Sexton 1959 Spatial and Temporal Movements of the Painted Turtle

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Spatial and Temporal Movements of a Population of the Painted Turtle, Chrysemys picta

marginata (Agassiz)Author(s): Owen J. SextonSource: Ecological Monographs, Vol. 29, No. 2 (Apr., 1959), pp. 113-140Published by: Ecological Society of AmericaStable URL: http://www.jstor.org/stable/1942200 .

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SPATIAL ANI) TEMIIO1RA MOVEMNTS (O)F A PI'(O)PULATION OF THEPAINTED) T RTL, H(JIYHRSEJIYS PI(CTA MALRI NATA (AGASSIZ)

OWEN J. SEXTONDcpart nint of Zoology, IVash intool l7nill'(sity, St. Lollis, Missouri

TABLE OF CONTENTS

PAGE

INTROD (lrITON . . . .. . . . . . . . . I1 3

lJo(CAT^rIONAND IF,)ESU(RIi-TION OF TilEF AREA ........ 113

MNETrHODS OF ISTruDY........................... l15

A IB)RIEF 1)ErRuHIUI OTII)Y OF THE

POPI lATrION ............ .......... ...... 1

Tii: ANNUAL (Y1CE OF' ('111!J1scings A(CTrIVITYr.. 117A Brief Synopsis of tlie Aniuli (y-#e ... . 117

The Pievei IiI Sn 5011.................... 118The VXeiii1, Sensoi ....... 119

The verIlIl I (ci igln tiOll ,l1n1 the

ellign llts ...........b.i.l.. ........ 12\

Eln vi iOnlinleIntl fen tillures of (rn ne Pond

,11141 Slllrrotlldluing ,1en durS11ling thle \'('1 11,11

emiiigrntiol. .. 12Tlhe 1thinluenice of Nvnter telileln-tUle-( 101i

('Illel-(t Oil ('liligl-nltioll .13. 1

The extelit of thellispersn I lilovemelilelits . 124

PAGE

Activities of the Ch ryso(myS reInining

within (Cr-me Pond . ................... 1 23

The Aestivnl Seson1. 126

Spatialt reorganizaition of the p)opl0ation1. .1 26

lResponise of the populaitionI to vegetation

(cla liges. 1-27

(espoilIse of iindividuIuIh turtles to vegeta-

tiolI ('1n:1lges .1 29

F'eattiloes ('0111111011 to 1)18 iits utilized 1)by

(7 h1rYs,;c'. ............................ 131

Advanlit:ges of the T-stintettnie ........... 132

D)istribuitioni withinii 1)1 llt eds..... ....33Activities of ChryScoys OilollnIatS of floa tiing

vegetationll .13. I

U(tillu1( of COhrscoinys to activity arleas of

forI er ven s . . . . . ...I,S 134The Antitimiiah SeaIsonl. 134

1I)uSCUSSIO()N.. . .. .. . .. . 13)6

SU M1\1AlARY .. . ... . . .. .... ... . . . 139

LITERA1T RE (TEPI)D .............................. 139

IN\TRO1)OD CTO-1ON

There has been an inerea sing amountofe informa-tionI aitulalll1llbltill over the l)ast two or thiee dleeables

which dlea(ls with the territolries, a-letivitv' Irangles,slandhome angesof nn111an imls, both vertebra ite andinvertebra ite, aquaitie aInd terrestrial. That this in-ter-est has beein aretively slhare(l liy investigators work-ing w ith turtles is shlmvnl by the pa1pers of Pearse(1923), Catg1le ( 1944, 195(0), Williamls (1952) anBre( kenr1lidge (1955) ()ii fresh watter turtles, b, thIoseof (Ca-ir &- Caidwell (1956) aiidl Ca17rr & Giovannoll

( 1957 ) ()on imairile turtles, anruidb1y those of Breder(1 927) , Niehols (1939), Woodburv & 1tIrdv (1948),in(l Stiekel ( 1950)) onl terrestrial speeies. These inI-

vestiontiois, ais wvell ais mo((st others deafling with thespatial moveui enlts of assorted anmails, Werle(( orleoeelrledw ith estaiblishing whether or niot the amnillsls studiedrestrictecl their -activities to limited alres or, if sueh<areas were foun(l to exist, with their size, shal!e, aun(

perluancnee. The lpresent inivestigaio 0 wa ls unldelr-taken with the follovinv , enls in view: (1) to verifyOr refute the gencral belief that the painited turtle,ch r,,secals pichta, restricts its movellients to certa.inIsmall areas, (2) to identify axny physical orfactor associated either with changes iii the size in(llocation of an activity ranige or with the spatial anidtempl)oral stabilization of those saiiie atreas, (3) toascertain the seasonal vairiation inI at(itities (of a.population of turtles over a period of several years.

A (lebt of g'ratitu(le is (due Professor FrederickHI. Test for his ail. Dirs. Pierre I)aDsereclu, Francis

v'ans, Nornian Iartweg, Herbert Wagnc er tl ad

I Ialipt()n (Carson gave imallny valluable sullggestiOnls.The laIte Professor J. Speed Rogers and 1P1rofessorT. II. hlubbell offered mlc the use of the E(dIwini S.

(G'eorge Reserve. The eurator of the Reserve, I)r.II Xill , Cantr all, and the custodian, Mr. LawrenceCaniburn, helped mne considerably wvhile I workedthere. I)r. F. K. Sparrow and Miss L. IIillis kindlyidelntitied the plants. Mr. Laurence Jobiiie dlrew soiiieof the fig-ures. Financial aid was provided by the

N'atioia 11 Science Foundation, the (e orge ReselveResearch Fund, an(ld the Summer Research Fund ofthe Graduate School of Washington Lniversitv. Mywife, Mildred Bloomshurg Sexton, was a constant

LOCATION AND DESCRIPTION OF TIlE AREA

The population of turtles most intensively stu(liedinhabitec( five bodies of water on the Edwin S. GeorgeReserve, located in Putnam Township, LivingstoiiCounty, Mlichigan (Fig. 1). These five are SouthwestSwamp, Fishhook Marsh, Crane Pond, the I)itch, andCattatill Marsh. During periods of great pIrecipita-tion, late winter, spring, and sometimes (luring thefall, some water flows southward from FishhookMarsh into Southwest Swamip, while the remimainderflows eastwar(l fromt the former iilto Cranie Pond.

As the flow continues into Crane Pond fromt FishhookMarsh, the water level in the latter drops below thatof Southwest

Swaamp so that the water fromlllSouth-xvest Swamp reverses its flow, passing hack into Fish-hook Marsh and then into Crane Pond. The wvaterexits froiii Crane Pond through an outlet to the east



114 ()x W en .J -IN 1((logic II loiiogras)hsVol. 29), No. 2

SOUT..EST t O

FIG. I. (raiie Pondl a(1n Ileighib)oring bo(lies of water

StLdied(l (lulilig t11e (COll^SC Of t1e presenlt investigattioII.

Sy1l Lake, not ini(licated on this map, is located about

400 iii south west of Southwest Swv.;mii). Direction of

wa ter flowv is illflicatedl Ilya1 r1rows.

and flows eastward through a ditelh until it loins a

lrmanch of Honey Creek, a tributary of the Huron

River dlraina-e svstemu in southeastern Mic'higan.

Southwest Swnivp, about 1.20 in southwest of.

Crane Pond, illsa;,n area of about 15 acres, of win cli

S are open dulring periods of high water. Inl 1946

a seni-circular moat was d(ug', ai(l this always con-

tains water except during periods of extreimie drought.

Frequently the more shallow areas are dry fromi midn-

suiimner until late fall.

Fishhook Marsh, about 2'0 Ii west of Crane Pond,

has an overall area of 10 acres, but most of the area

favorable for turtles is concentrated in an acre ponidsituate(l just west of the inlet of Crane Pond. Fish-

hook Marsh becomes (li\ (lurin- the sumiiiei.

Crane Pond (Fig. 2) is a permanent pond (lug' by

d(rag-line in 1946, with an area varvin- froiii 4.5 to

5 acres., Previous to its construction, a seasoiial 1)on(d

was present in the sallie general area after 1938, when

the tile dlraining the area was destroyed. At preseiit

the maximum depth varies froiii 0.7 inllduring ex-

treiimeiv dIr autumns to 1.3 in during the spr ingt,.

The water is clear except during heavy ra ins. The

substrate is clay, sand, and organic iiiuck. The ele-

vation (If the pond is 274 Ill above mean sea level, and

to the north all1(1 south a 11bills pa-irallelilng,the south-

west-noitheast orientation of the pond. These hills

attaiin n elevation of 297 i and clhannel the }pre-va ili weN''St(erly wvillnds over the p1)(1 surface.

The I)iteh, 170 in east of Crane Pond, was (lug inl

1950 and consists of three linearkl arrange(l poildlsvarying in depth from 0.3 to 1.3 Ill with occ'aslional

(leeper holes. Thes;es three pond(s ontalin water

throu-hout the year although the flow of water iiito

<anr(lout of the Ditch is seasoiiul. Cattail Marsh is

iiot (directly connected to the Ditch, but it is withiii

15 in. of it. The area of themautrshis about 6 acres

although the amount of open water is variable. All

except a small portion of the marshl becomes (lix

durling the summer.

45

S~~~~~~~~~~~~~~~~~H K/ ~~CONTOURINTERVAL-SIM,"

| 5

5~ CRANER PON

Fio'I. 2. Map of Crane Po01d(, Edwin S. George Re-

serve, Livingston Co., Alichigani. The ntumnbers around

the I)eriplhery rep)resellt certain of the fifty-seven stakes

arounidl the p)o01(1 itiargin. The inlet (IN) and the outlet(OITT) are shown.

Since water ceases to flow out of the t)itch into

Rloneh Creek during early summer and resumes flow-

ing in early winter or later, the five areas in which

collecting was (lone are frequently isolate( f rommithe,

other parts of the same drainage system. This isola-

tion must have been even more comiiplete before 1950

when the Ditch was dug. For these reasons the area

under stuclv may be considered as a partially separate

Unit.

Individuals of COmrisemyis picto inhabiting four

other areas were collected (luring the summitierof 1957.

One area, Sayl Lake, is a shallow inarl lake with an

area of approximately 40 acres. This lake is 300 mti

southwest of Southwest Swamp, but there is no (i-

rect connection between the two. However, prior to

1872, Southwest Swamp drained southward, either

into or close to Sayl Lake. Hidden Lake is a senes-

cent boo lake with an area of about 2 acres. Al-

thoug1h it is in the samne drainage system as CranePond and related areas, Hidden Lake is separated

f rom thein by a tamarack anld re(d maple swamp, and

there is l(Odireet passa-e through this swanip. Hid-den Lake contains water throughout the year. Neither

Island Pond nor Burt Pond, both artifieilal bodies,

are (lireetly connected with Crane Pond or related

areas. Burt Pond has an area of about 1. acre, anl

Island Podl, an area of about 0.5 acre.

TIhllemiost llabundant aquapatic lllats tounol within

Crlame Pond, the aiera most intesnsely studied, are the

followinig (1) emergent plalnts-T Iyph1m litit~oli,

A Iis 0)( triiUle, A(igittO rwi latifolio, leersia or1zoides,

a1(1l h'Ieoeh 0liS ocolotri s; ( ) rooted l)plmnts withfloating leaves-Potloinoq(ton i1iipl/'OolO/s' P.J 100tons

all(ldNifpl)(r odrenai (3) roote(l plants with sill)-

ierged le.ltves-.Potamog eton pe(( tinotus, P. folioslos,

10. inplflifols, NaOj(s fle(ills, EleocPl(iris O(Oic -irs,

amidhnon imliciflllS longirostris; (4) anchored plants with

submerged leaves; or thalli (hara sp. and (Certophlll-

loim demoersooinm;(5) anchore(l plants with floating

thalli-varlious filamentous algae.



April. 1959 l'OPULATION OF TIlE. PAINTED TU RTEI I'1t)

Other a(luatic or*seilfi-aquatic plaiits ot lesser iml-

pollrtiilce are C(qp)ersl.strs igosS, Elcochari8 sp.,

(/ mhphibrioum, 1'. h !dropiI)eroides, Ran1.1cUdlls scelera-

tifs, S cIte/lla ri eJviloliifolia, 3e1nth ( (arvlensis, ailld

Bideus sp. Epizoic algae are Basicludia cholOnliil1

ailld B. cro.ssa.

The more iuiporbtait vertebrates associated wvithCrane Pond inelude:

AlIuIIIII11aha: raccoon, IProc!/lo lator; miuskrat, Onl-

dat ll it)bethica.

Aves: pe(l-hilledl grebe, Podimlnihs p)odlicels;g-reait hlne heron, A rdea herodias; green heron, BIlto-

rides riresceenks; American bittern, Botamlirtis len tigi-

Ilsls; spotte(l sandlpil)er, Actitis mncl darial; blacktern, ("hdidonils nigra; belted kinigfisher, Meguaeryle

Reptilia Blanding's turtle, Emns, blan(linyi;

pIainted turtle, Chrysemijys picta.; common water snake,Na trixi Sipe(lonl; ribbon snake, Thu iimo/)lh is SlO iriths;

eomiiuiioin garter snake, T'. sirtalis.

Aiphibila cricket frog, Acris yr/i/ils.; bullfrogtR(aa (atesbheila ; leopard frbog, Rt. pipiens.

Osteielhthves re(lbellv dace, (Ihroi0llis oos; goI-lnl slliller, Noteiii iqon us crqs oleeau s; mud millnow,

Umbra limii.

METHODS OF STUDY

Aln attempt was masile to collect every turtle inthe population by employing the following Methods:

balited hoopnet traps, sunning traps, funnel tras)s in

the inlet arnl outlet of Crane Pond, a retainillng fetice

on land, inoodling or mnuddling froin a boat and oi1foot, use of a hand net from shore aInd from a boat,t11(l selning.

The use of a dip net from a boat and front shorewvas very effeetive. An attempt was mnade to netthroughout the entire pond within three or fourcollecting days, and the turtles( did not appear to be-reatly disturbed by collecting.

At times of low water, muddling, or feeling aboutill the water with the hands, was very effective froma boat. It was less desirable when depth necessitated

wafding-, since this disturbed the rooted aquatic veg(e-tation.

Three sunning tralps were used in 1953. Eachconsisted o(f four 2 X 4 inch boars(l nailed togetherill the forni of a square, 90 cm )11 at side. Beneath

this tranl1le Was suspenlded a basket of I ill iiesh

cliickeii wi me into whiech the turtles fell wheml they(lived off the 1)oards. The trapls were plctell olly ill

(aIr(eIs use(l as nlatural SUn11ning' sites or. ill other regions

of coemientrati(n. Turtles (1Joul easilyv e(scaie if: thecollector was not at hanml, thus activity was not inter-

rupte(l by a long captivity.

A rettaiiiinig fel(es 10 in hill and iniade of chiekeniwire with a mesh of 1 in wvas erected onl laod to the\vest of Crane I'Pol, an(l it extended for al)lout 100

to south of the inlet parallel to the Nvest shore of' the

lpomid. Its puurpose wvas to detain turtles tenmporarilvais they moved overland at that poinit. Escape fromo

this fence could also be easily accomp)lishle(l if thecollector was iiot at hand.

A very efficient trap, which took advantage of theiseasonlal movements of turtles, was construete(l in theile1t of' Cranle Po1n(1of 1 in chickenl wire. A ciruliiararea of the inlet channel was surroun(led by a feiiceof this itaterial through which a funnel was inlseite(d

oil the downstream side. The fence was 60 cmiihighlaind was supported by wooden stakes driven intO thesubstrate. From each side of the funnel a lead fenceextended downstream at an oblique angle until it

passed onto shore. One lead fence joined the retaini-illg fence described above, and the other exten(ledonto shore for about 5 ia. Thus, any turtle mmmov-ing up the inlet was directed into the trap aild re-taiiied there until the collector appeared. Since thecurreilt somiietimiies washed an opeiling beneath thefence, some escapes undoubtedly occurred. After theuse of a simpler model in the spring of 195:3, this

trap was in operatioll continuously from early sprinlg,in 1954 until June 1955. Similar traps were used iII

tile outlet.

A separate identification iiiark was given to eaclhindividual turtle when it was first captured. Eachmiar-inal lamilla was assigne(l a number, aiid anm'

combination of nunlbers could l)e given for idlenltifica-tioll merely by cutting a V-shaped notch into the freeedge of the appropriate lamina with a penknife.

The data recorded at the timee of capture iilclude(lthe iclentification number of the turtle, sex, date, timlleof day, location of capture in relation to numbered

stakes Pulace(larouild the periphery of the pond (Fig,.2), association wvith, and relation to, other aililmlals

aiid )lants.

All turtles were released as soon as possible. Thisgenerally varie(l from 53 minutes to 1 hour. 1)ur]imigperiods of heavy migration, it became necessary toretain captives 12-18 hours. Turtles were always re-leased in the immediate vicinity of capture.

Most temiiperatures were recorded with staiidar dchemical thermometers anld Taylor moaximuma-mumini-m1um thermomlieters. Water temperatures were takenat a (lepth of :30 cmii,but the thermometer in the inletwas in shallower water. Wind direction wvas nioted

an1(dthe velocity measured with a Birami anemometer.Thiis reading wvas taken just above the surface of the

water at a location which offered the least resistanceto tIIe wN ind.

Silnce the distributiol of CliilJlsemys thiomghlout

(mCane P0o1( was associatedl very strikingly wVith that

of vairious )iilts, thmelocatiolls of the beds of aqiu-Iitic

l)lants were mialpl)ed. Each timiie a turtle was cap-tlmed(l in Crane Iond, the types of vegetation iII time

imiiiiiediate viciimity Nvas recorle(l, mfmil iii 1954 an1d(1.19571 llial)s of the aquatic flowvering planmmts m11mdthe

niomm-lalanmktonicalgae were iosade at intervatils thtimougi-

ouit th)e veaim These two miietlods eaiable(l oII( to fol-low the, changes in location of the plant beds for twoyI ea r'S.



1OWEN J. SEXTON E(ologicallMoniographsV'ol1.29, No. 2

A BRIEF DEMOGRAPH-1IC DESC-RIPTI O)N

OF THiE POPULATION

Diuring the period of studly, froim Mlarch 115,19153,

uiitil Septemnher I5,, 19157 878 indlividual C1hryse4mys

Jpic1o were eollectedl nimarkedaii(l releasedl. Most of

thle aictive ciollecting wals (oiile IIIOI01 aro01ii1d CraIne

Poinl, hut soiie collectiiig, Was also (lone 'in SouthwestSwav,nipiII, Fishhook Marsh, the Diteh, and Cattail

MarCishi.The Craiie Pond( section of the p)opulatioL1was ohservedl aliiost (oiitiiiaill-v froiii March 15, 19153

to April 30, 19515. Less Hitensive studies were ear

iied out trout May 1, 1-955 to -Aug-ust 20, 191515; March

23, 1-956 to April 1, 1956; April 1-3, .1957 to April

21. 1957. Another intenisive study was iladle from

.JuiU11CI, 1957 to Septemher 12., 1957. InI addition to

thle 878 livinig aniiials calpturedl at least once (luringn

this'- eri-odl thle following iiibers of (lead, nakd

turtles wveic (ollectedl iii the area: :1953,103 ; 1954, 14;

1955), 1; 1-956, 21 ; 1957, 2 ; t )ta1 141. A few Chrq-

sum pluo wee ailso co(llected(lat thle lollowil1g loca-tioiis (llriiig the suimmercof -1957: 11idden Lake, 17-

Buit :and Islad Ponds, 18; SalLake, 34.

The prop)ortioni of marked -a11( unmarked a iii nals

(a iitiredl thrmoughout the course of the Stli(Iy variedl

regula1-kulv fter a ceita iii1 point waV.s realChiel JTahle -1).

TxnuEi 1. '1lie percentaige o)f nia rked anim.iflas ca.-ptured

lutring the varions timues of the yea i. The decrease in

thii eeci(iit~ige o)f imarked amniua is froiu the spring a iid

fall1 to the Siummiier Is the resuilt of the young aljlimal's

eiiteriiig the o('pulatioii a iii of the (liticreulltu~l1response of

theimaarkdclanil ttimiu ked1 an iii as to the (01 lector Iduring

Total P~ercenit-

iumbher age of

Period Activities of the of marked

anuimials anjinals animials

M~ar.25-Mlay 1, 1954... Emigrating 372 53.6Oct. 3-Nov. 19), 1954. ... Emigrating 225 84.0

Mar. 25-Mlay 1, 1955 ... Emigrating 103 76.7June 1-Aug. 20, 1955 ... Various 44 45.5Mar. 31-Apr. 26, 19)56. .Non-emigrating 01) 65.2

turtles pillsdead ones

Apr. 15-Apr. 21, 1957. .Emigrating 68 69. 1

turtles plusdead ones

Junme11-Sept. 15, 1957.. Various 121 54.4

During- 1954 the numuher of turtles (captured (lurlig10

the spring10 em11igration waIs still rela-tively 0 w, hut dur-

ing) any eiiiiratioii thereafter, the perceniitage of

marked amnimailsea1)pturedlvaried from 69.1 to 84.0.

Af ter thle sp)ring eniigration of turtles from Crane

Pond, few returned to the area until the mntlvi-iig

hodies (oh water hega-n to dry ulp. The p~ercentage of

marked animals among those ea lptuiedl in Cranle Pond(

during- the suimmimerva-ried from 45.5 to 54.4. This

drop in the perecnittmge of marked aniinials, from thle

spring to the suntmier wa,-s almost certainly due ta the

differenit c-ollecting techniques usedl. During the spring-

the iiilet andl outlet traps were responsible for the

ecpture of most of the animals. These traps were

evi(lentlv not associate(d with eapture by the turtles

aind the niarked and unniarked animails di'd not re-

spondl (lifferentialily to them. However, (lul ing the

suimniel' when most of the aninials were collected by

netting froi a boat, the inajority of the turtles whieh

remained at the surfaee as the colleetor approlachedto within three or four feet prove(l to he uniiiarked

ninialIs while those which (love beneath the surface

an(l lswain wayv while the netter was still 10-15 ft

aiwayvwere (chieflv marked inlivi(luals. This (IiffeellrenC

in the behalviVorof the nlarked and unnIarked turtles

illnreasedl as the studly p)rogresse(1. The lower pro-

portion of imairked aninials during the suinnier wasalso (dec to the ftat that the young of the yeari ( de-

posite(l as eggs (luring the previolls y(ear) eiliergefroimi the nest ill the sprinog and11 a ficst axvailable

for clij)tulle (lulring the sulilIiler. The grea test pro-

portiomn of Ina rked turtles collecte(l ( 32 of 34) was

from Alnay 19 to A\lav 29, 19 515; 1miost of' these aiiinialswere lirge f'eiiialelles iilvillg a1bout oii Ia1l(1 Ilringll the

II est iII0' S(elas(o.

()I thle hansis of the ab)ov e Statemiients it wo muld

appear thiait al miniliui of' (9-S4'` of the aniiialn s ill

the poplillhitioi llan been mari-ked, amid a value ((1t

.'a.()'/, iv be ta kei as averag-q(1,-e.There werIe at leclst

716i (Chril/se s (i'(t aliIve Ill 19513; 5(0 (hilitioiia

iil(flii(lullls of ulncertafiii(W'a w(ere Ponba bl1aso 1iieni-

bers of this ye(allls pop)ullltion. tIsing these ligllres,

it c11ibe a ssuil ed1 thalt there were ughllv 1 0(000

pll inltc(l turtles iiihacb1itilng Southl\0west Swnll lp Fish-

l1ook Mli sl (illCine Pond, the I)itelhi a11(1 (-tttliil

AIl rIsh.

'Tlese 1000 ti ltles were (listi'ib)lute(l ONver.lIl aii't'a

xNhlliel vnIlIe(l froiiiI .1bout Ii li'ies (1r11'illo 1(l0(o(I Iof

ext1(11e a (1rlloglit to about 25 11tes (lurinig periolls of

IlighI wnter, (a1tll-1thog ill neitherl.l nse wXIIs thle tOtIl1

ea1(11limli'olrilX'1! suitalble for the turtles. Thu1Is, tlle

eCOlllllI il (lemisitV varied froill 166 turtles per (1Iler

to 40 turtles per lore. The highest (lelnsitv oll)serelel

w\1II aillg giegil tion ot(f at lelAst 422 nllniilals ill a bed(

of Poto(11(1oy(tonl JfoliOSll5 illeasurilg 15 X 5 ill (807

sq ft) a (ei lsity of 2265 turtles per (acre.

The )ge 1111i seIx (listlibutioii of the 75fi turtles

known to be alive ill 1953 is shown In Fig'i. 3. Theiiethtod bv which the age (f the turtles wsx.l estilllnltc(l

will he (lescribewd in (411ilil elsewhere ( Se'xtonI, 111ivu-

scrlipt). Briefly, it a.tteiiipts to cstiniiiate the agOe o f

inllividllllll nIninlals by collip)aring the miedlil length

(If the growth aniiuli visible oin the right .abdomilnal1

l~l illn~l to exp)ectel vaflllesxalculate(l froiii the enitire

:opilll.4till.

Fenili-es evi(lenltly olutnuillber 1111('s ill this lolpull-

tion ; the Iletusll sex rnltio is 1.49 Y Y / 1.0( for- the

(G04 nlililllwlls whisbe sex w5s known. Since soiiie of the

juveniles were not c.ipturedl tifter they had(1 beconle

Sexu'lll i. .lllture, theil sex couldl not be detelri ilied,

.111d they were cllssed(l .Is juXeililes. Al ll(es Illltureenrlier tharn feilllm1es; the sex ia till of thle II iiiiiils

inrge eilnougli to he sexillydv imlltulre is 0.76 Y Y/ 1.) .



April. 1959 POPVILArION OF TIlE PAINTED TrlRTL]E 117

OVER /40 Oft

13 BEFORE

13-FTTI

141

12- -'42

I1E .-'43 z

0 - FEMALES ad/MALES -'4

z 10 4460

? a8 //////// \\ \ 46

?7 -47

6 48wd 0

5- _ c///,////////'49 4

4- *50

3- -1

2- .-'52

I_1 _ _-'53

no 40 30 to 10 0 la t0 30 40 50

NOS. OF INDIVIDUALS

HL 3. The ige 111(se Sx diistribuitioni of 756 iin(l dllvldd Cli/.sm i/s picta uuilimibiting tue (1811e Pond a rca

11llrilng the growvlng sel0so11 of 1]93. Tue solid lhorizoiita' 1)818s relpreselt youlig turtles whliose sex wvas niever lefi-

iiitelv d(Iterhile(l.

About 210()t the 756 annals were ol0( enough to

tliltedlte the ((nsti-tictioin of CraneIneIond in 1946.

Thiese ()1(1(1 turtles uay wenl1I1ive b)eeInresident in theteilln 1)01y pmids an(11dsw8i1lll)s \vhieh existedl between

I938 and 1.946. At present there is aI simnuilarsitun-

tiOl ill :iotlthier p'i)t of the G(mcl-o Reserve. Two

small, tepllpmoiay 1)ponds support about 50 turtles in

their two 'lwres olu'ing0 S0111oieyears. These ponds be-

couiie liv' (lulring uuui(l-sunmlmer and remain so until

lite fall oi earlyI iIIt er.

The renlminilln 546 turtles began their season (o

glo(Wth (l11ridini 1946 or-hlater. There has 1)eenl a notable

(leeline in the nuimbers of young in the two most

recent agoe classes, but, otherwise, there seems to have

been a stea(ld population increase since the formationof the l)permanent bodIies of water. The cause of the

decline in the first and(] secondl classes has not been

i(lentifie(l.

During the entire period of study the following

minimial numbers of young-of-the-year turtles were

a(lded to the po)ulaltion: 1953, 63; 1954, 54; 1955,

21; 1956, 17; 1957, 1'); total 167. Corresponding

mlortaility figures are: 1953, 110; 1954, 37; 1955, 7;

1956, 61; 1957, 7; total )2)2. These( data seemingly

indi(iate that the p)opulation is in a slight decline,

but while most remiaiins of dead turtles (except those

of vervy youngo ones) (1o not disalpl)ear for manmy

months a d tcainbe found relatively easily, not enou1gh

time ws ,s1)ent in collecting, the young-of-the-yea-ir

from 1955-57 to make sure that most of these small

aninnals were obtained. It is probably more lerason;-

a1)le to cmjilp1arethe aver'gie nata lity ligure for 1953a11(11954, 58 young per sea-ison, with the overall mor-

talitv rate for 1.953-1957, 44 per year. Althoughthere aIre still ialiiv sources of erilol ill these esti-

11a.ates, the rough laIta. x(,o111(lseeni to indicate that

the ntlinler ot turtles in the population is- relatively

stahible.

TIIE ANNUAL CYCLE OF

(CHRY/SEWM S ACTIVITY

A BRI EvF 8Y NOPSIS OP THEri ANN A1L-AI CY(CLE,

A short review of the annual cycle of the l)aintedturtles inhahiting the Crane Pond area is plresenIlte(lhere so that the subsequent detailed study of the

spatial and temporal chanoges in the location of the

population may he seenmas parts of the entire annual

cycle.

At least a few Chrysem fs are atctive as soon as

the ice coVer hegins to thaw, uisually between mid-

February and mid-Mareh. During this initial coolperiod the movements of the animals are limited to

ptassing back and forth fronm the (leeper areas of thme

ponId to the more shallow areas or to the shore. Mor-

tality is very high at this tinle of the year.As the water temperature rises, the number of

active animals increases, an(l when the water attains80C, usually in late March or early April, the animals

emlirClte, leaving Crane Pond. Most travel westwar(l

to Southwest Swamp, but others move eastward to

the Ditch. A few renmain in Crane Pond. Although



118 Ecolo-ical MonographsI Ill-~~~~~~~~~ OWEN J. SEXTON IVol1. 29.) No.2

iilost of the e(xo(lus is over within aI4-wk period, a few

stlraggler-s (1o not leave Cratie PXond until mid-June.

A va8rietv of activities assoeiated with reproduction

takes place during, the s)riLng. Breeding, although itmay tfatkep)lace at other setasons, rea'ches a, highl pointduring the s~pring. It is first evi(dent about the time

that emigration begins. The turtle hatchlings, from

eggs (letposited the previous year, emelllrge fromn the

il est cavity in lnid-spring or later (Sexton 1957), hut

thev' (l() not emigrate. The dates on which the first

hatc1ht>ling0swere observed for any palrticular year are:

May 6. 1953; April 20, 1954; April 19, 1955. Nest-

in occurs1 (luring late M1,ayor early June, and, judg-

ing ftromi amy records, most of the females deposittheir eggs within a relatively short period. Positive

lnestin)g recordIs are as follows: ,June 7-June 11, 1953;

Mav' 21-May 24, 1955; June 8-June 11, 1957. These

pemrio(ls were usually associated with rain. Other

workers have indlicated that the nesting period of

(Chrsetiois may be much long er. Legler (1954), onl

the basis of his own observations, states that nestilng

took p)lace froni Jtine 16 to ,Julv 14, 1953 at Sand

Lalke, Nicollet Co., Minn.

I)nrin1g late spring and early summer most of the

turtles arne distril)uted between the bodies of wa ter

leril)her'al to Crane Pond: Southwest Swamp, Fish-hlomkMarsh, the Ditch, anld Clattail Mlarsh. As theseareas begin to dry up, the animals gradually move

back into Crane IPond,(aid bY fall mimostof them are

re-locatedl there. This imm111igrationis not as distinetas the spring emigration.

Growth of the animals and she(lding- of the lami-

nac also occur during the summer. Recogniizably newin HIem1entson the abdoniminal lanminae are first visible

betweeni id-iMay and early June. Growth ceases by

the end of August.

The activities of the painted turtles nmay followo0ie of two patteriis (luring the fall. If' the water

level remains low so that Crane Pond is the principalref ugiumn 'in the entire -area, the animnals will reimmain

here. As (0ol(1weather approaches they will move into

the (deeper sectionls of tile pom(i. At least some of

themmiwill be active until the perlmnalellt ice coverfi'omns in late Novemmiberor early D)ecemuber. If, on(

the other hIamid, there is sufficient l)recil)itationl to

lraitse the walter levels of the adjacent )onds andIIIarIsmes, aI fall emiraltioln will occur, and tile emii-gramm1tsxx'ill hibernate in the outlyvin' areas. Those

turtles wNlhich meimmainin Crlane P)ond ummder such con-

(litimos will emlmgraitethe succeedling sp)rillng.A s im(liicate(l pireviously, the po)ulmlation of l)ainte(d

tUIrtles living'1 in thle Cramlle 1)()11(1area is relativelv

stalble in mimummbers,but it iia.1bits aim environmiment

wvhiehulm ll(Idergoes immarked seasonal fluctuatiols, e's-

pec^iillx iii temmml)erature,water (delithi, surface area of

tIme waIter', a111(1iii the 1imatllreof tIhe a(quatic vegeta-

tiomm. rThe aIctivities of thme tilltles weresetronglv

aiffecte(l by these chmaniges, amil it was the pumpose of

thias imi1vestiga.1tiomito stll(lv tle effects of tile envilmomi-

mielmitalfluctutationls upon the (listributioll of the tur-

tles. Tlme behavioral patteirn of COhisoeiys aimd the

phenology of' Crane Pond are sufficiently (cistilict so

that five seasoiis may be recogiZn(l: the prevern'l,

the vernal, the aestival, the autumnal, and the hiemiml.

In this paper the seasonal. activities of the pJailltedturtles have been descrihed ont the basis of the first

four of these season-is.

TmHElREVERNAL SEASONTThe plrevernial season of the Chrilsem:ms annual

eycle begins with the fin.-alilnitingb of the winter ice

cover. lii 1-953 the ice (over hegan to melt duriiig

the first week of March an(l had(ldisappearedl by

March 11 when this investigation began. In 19.54the ict cover started to disintegrate on February 16

during an unusual warm spell, and a third of the

Crane Pond surface was open water by February 25.

however, the waters again becanie completely coverel

with iee subsequent to February '25. The final imelting

of the ice starte(l on March 13 aiid was conlleted hv

March 20. In 1955 inelting began on M1arch 11 and

was finished by March 13. In 1956 the iee begaiimelting at a very late (date, March 31. In 1957 the

exact (late when Inltting was initiated was unobserved,

but it was betweeii March 2' and March 18. The fif-

teenth of March represents an approxiniate averaIge

for the (late when ice cover is completely mieltedl.The end of the plrevernal seaisoni is heralde(l l)y a

mt'ass emi-ration of Chrlsempqs out of Crane l'onld.IIn the spring of 195.3 the first emigrations were no-

tice(d on Marchi 21. Eniigration was well under way

by March '25, 1954 and March 31, 1955. 11owever,the data for 1955 are scanty, for most of the turtles

had left the pond durinig the previous fall. The date

for 1956 is uncertain, but emigration evi(ldeitly oc-curred about April 7. SomIe COhrqlscms were movingl

out of Crane Pond about March 18, 1957, but an un-

seasonial cold spell interru)te(l this m1ovellelnt, and

emi-ration was not resumiie(l until about April 18.

March 25 is an average date for the termination of

the prevernal season.

Environmmiental condlitions during the p)revernialsearson are such that the activities of the paintedturtles are severely curtailed. A niaxiniumo-mininiunthermnomimeterlocated at the western end of CranePo01(1 registered air temiperatures which range(l froij

-9.4?C to 150C in both 1954 and 1955. Wcater tein-

l)ematures (luring the saime ,yaIrs varie(l from I C to1)CC. The observed lmlaxilllUIi1 velocity attainie(d bythe wind 1roaring over the unmobstructed1)0o1(1 surface

was 380 ft/nunin. It is these two factors, teimuperature

l1 windl, which influence the aictivities of the turtles

verv strly-mi(-INliiii this tillie of the yea in, but o)ther

faictorsi such as redu(lice(h oxv'e tesllsiomi i the wa'.terl

a'Ie also iniporta't1t.

I)uming thte late hietmall (wintertl) or pIevernal

periods miost turtles are observed only ini those p)laIicSwhich aire p)rOtecte( froII the wind. Such 1)m'otected)lI(''es include i(T-coMvere(Id wa1ter, the lee si(le of shmre

pojeections, alnd areas protected bv veg-etation, suchas clunmps of Typlhu. Tie few (Curyscouqs observed

in situations where they were eXp)Ose(lto theft orce ofthe wim(ls durinig these cool pmeriodswere alimuosthelp-



April. 1959 EVIDENCE OF PHOTOPERIODICECOTYPES IN TREES 119

less. On several occasions Chrysemrys were found

entangled in floating vegetation which had been cast

up O1n shore or rolled up onto the shallows. Such

animals were unable to escape from the debris. Tur-

tles observed in open water were carried in the diirec-

tion of the prevailing winds and coul(l not swilm

a-ainst this force. One aninmal, seen March 16, 1955

was in shallow water and was being transported in anelliptical path perpendicular to the shore by the

waves. The cloacal temperature of this animal was

7.SC, and the velocity of the wind was 380 ft/min.

Turtles collected in protected areas friequently had

lower cloacal temperatures, sometimes as low as 1.4?C,

but they were able to move slowly away from the in-

vestigator, indlicating that they were still inl control of

their m11ovellmelnt.

The Chrqsemojs observed swimmingl beneath the

ice appeared to be trying to reach the air. One of

the nine turtles observed swimming beneath the ice

sheet on FebUarY '23, 1954 was Iiiovinu, shoreward.

The water temper ature was 1.5?C, and the dissolvedoXg enIl was 6.6 ppm. The Chrysemys alternately ex-

teIl(le(l and withdrew its head; the rostrum was

piresse( against the lower surface of the ice. Occa-

sionally the mouth was opened, possibly in pharyn-

geal respiration. Other turtles were at the edge of the

ice sheet, the head extendingli into the air while the

body was still beneath the ice. One iIl(lividual pro-

tru(le(l his head through a small crack in the ice.

Similalr activities were observed (lurIing the late winter

aid(l early spring of three different years, indicating

that this type of behavioi is not uncommtion for Chry-

D)imriiig the'l)evei-ntal seasoii the turtles move into

locations where their body te ml)eratures can1 be inI-

(1case(l, that is, iiito sh-allow waeter or up oil shore.

Ill suclh situations the (Ialkene(l car-apace absorbs the

loget-r wave lengths -11and the body t'eml)crature of the

trtlfe many he higher thanl that of the sullrroudl(ling

mendiumn. Foi exampl)le, onl MAlrchl19, 1955 a Chrly-

N,*M'I/S (Ia pltu ed hellenath the ice had al Cloacal tem-

l)(i'-tuic of 6.()C(0 while the wa-Iter tinepcrature, mneas-

ulred hy thie same tlhelrilmonletetl, wmasonly 40C. This

in(lic(aItes that evelnt turtlesXhelneth the ice are ab-

SOrbI hgil enroughll of the longel wasve lenllgths to raises

theli! teilhh)craltur e aibo-eA that of the water. Addli-

tiolial (Icses of diffelelles betweell the temhl)crature

of individna(ll tllrtles a lmd that of the sillromil(dillng medi-

umnaic presente(I in Table 2. There ac-e four ilstaneces

in xlhieih the temnlm)erlAtur-eof the animal is mtorethan

l C lowerl thian thit of tile surlrou1ndilln medium, but

ill thllree of these thle tur tles were ('1o1ining from loerl,(m0(1 (l1)thls iinto siallow watecr or up) oIn liI(. There

alre sevell tllrtles with cloacal tenIl)erl-atires withill 1C

Of the 1me(dIIu; thc((t o al teilll)ratulre of the Ie-

HICIinmiing14 Ch iS-q .mys is nmor1 thani 10C" above that

of the suromun(lidming medium, iii some cases 100 olr

mmc highelr. The grI-eatest (discrepalnlecs. ill tellnpera-

tulre ocur ill those an11iinmlalsvhicllhlae sunlnling. onl the

shor~e.

The movements of the )ainted( turtles withini Cramie

Pond~ alppear to be relatively limited during this

TABLE 2. Cloacal temperatures of Chrysewnys active

(lurilig the prevernal anid early vernal season compared

with the temperature of the miedium in whieh each inidi-

viduall was captureml. The temperature of the imedium

was measured twvice, once with a black cloth wrapped

arounl(l the thermometer bull) to simulate the dark cara-

pace amid ommeewithout it.

TEMPERATURE IN ?(

Medium

Date Activity Cloaca Bulb not Bull)blackened blackened

March, 1955

1 . Sunning 1)o shore 10.4 12.8 ....

11............. Just on1shore 8.6 9.8

13.Sunning o01shore 19.8 9.8 ....

Resting in water 9. 2 8.0 ...

Swimming 8.0 9.4 ....

Sunning on shore 15.0 15.4 ....

Just crawled up shore 10.2 14.6

14.Sunning on shore 27.0 10.2 ....

166.u.. . Suig o01shore 10.0 10.6 17.4

Imwater 7.8 7.0 ....

199. . I ater under ice 6.0 4.0 5.6.

Sunning on shore 14.6 8.8 20.8

20 .Su.. . ing on shore 32.0 20.0 29.1

In water 8.0 6. 8 ....

21.Sunning on shore 8.0 7.4 12.2

28.Sunning on sn)oW 8.4 4.3 16.4



March, 1956

31 ................In water )11)derice 5.0 2.8 ....

II) water )1))derice 1.6 1.6 ....

Imwater under ice 1.4 1.2 .

Il) water urlder ice 1.4 1.0 ....

April, 1956

1................. I water underice 2.9 1.4 .

Is water urlder ice 4.6 2.4 ....

April, 1957

15. SunIIiIlg on1shore 13. 8 11.8 .

pertio(l of late winter 1a1(1 e(ally spring. In 195)4 five

Ch ry/S(slyo4 wX'(r captured two or immor'etillies befor el

thmeadivenlt of enlligrationl; the llinilllml (lileet(iitallnee

between ftathest points of lz-mtllturewitilill lCUIV OlIC

actetivity area va iied f room 3.4 to 124 mim, alVela gillg

41 lot. D)ulin- the analog-ous in 1955 sevemn Oh roil ifps

NNere cal)ture(l two o0 11mor e tillies. The (distallces

b)etwVeen1falrthest j)oimlts wvithiim at sing-le aeftivit tarea

vallie(l fromim 9.2 to 92.3 oe 1111(1averaged 45 111.

THE VERNAL ',SEASON

The vernal season eXtendls 0111 MAarch26 to Alay

.-31. Thle erite-iomi by wilich tile first (late was seleetel

Iias been Imlenltionme(dp-eviously. The vernllal s(eas0o1

is eo( elu(I( whemi Ceetil11 Sublnerge(l aIqUaItie pllIXltS.wimiell ale imimpor-tamtto (Io ry.semoys pict(i to to time



I 2 () OWEN e1. SEXTON Ecological Monographs120 OWEN 4. SEXTON ~~~~~~~~~~~~~~~~29, No.2

Wvater sflilwf. Jli 1953 Cluirai sp. was first ob-

s(iV(l nit the suiifawe of Cra1Ie Poind on June 1;

Rmm ullUIU1U( s lon ustris anldl soille otlhei species hadi

nttai(d(l the suitaict 1wbJune 14, but they had prob-

a ly be1)1 at the surface somiiewhlat earlier thiai this.

In 1954 (h Ui usp)., Vutoilmouyton foJliosmU, 1'. pecti-

Jul.I(si (11Rd 1llu(ld1Us iou ail-osti s18 beca e evid(lent at

the Watel surface l)btweein Max )20-2. Iln 19'5., (Ch(,ura

S1p., Po(mlo(JctoIJ f)lwslfs, and Rmoll 111d111ll/ Ili-

rostris-1rew to the Surface b)etweeil laN 1:3-19. III

1957) 1Potmnoyc((J(tons foeli.Slwms P.p)ec('nil{{tl..

fit'le8lun-

c ills iuuyii-ostr is ad111( ar11ius specles f(f iilanelt'llls

ait'1{ wxveieat the surface by eJuine 15. These varioii5

(dites ilnlicate that iAI v 131 is about the tiiiie aqinati c

phiits iii (ia ic Pond reach thel surface of the water

acilidtllor exteiisive floatillg Iiiats oflleaves aull thah1li.Ihllis lpeniilIl is ('cli:arateriZed l rilliniilyb' a.1111ss

(1lilIiiltioil ot iilost of the (hrls(111/ ill (Irane Pondto sliriolllnlllhilng bodies( of water anli bv the localiza-

tiol o t tllse tur tle s III; ill(i 1C1rne l'ollonl to

ceitail ii a ie iniWhich there aie Stinniino sites. These

tWv) o1(1(uli (i5esi the eilli-ngtionl anild the localiZat(li60,

-i ie (N-iliietlv il-l/itedl to tIe hi k 1)11 surface ve-(t a-

tioll ini (raile lPondl at this tille oIf year. Other

(evilts liiIllh Illiacterize this sea si0l11aie tlle initia-

t oillot fct(dini , niiating activities, aiil(l tl( eiergei(ice

otl ti Iultcllliiig turtles fillm the nests of the iprcviOUisva11. Nesting takes place (luring the eindl of the

xciria I ealsonii1 ai the beg-iiiiiiiig of the aestivzl one.

Tlie teililmperatule is very variable (urillg the vernal

seasl Iil (v'ei it it is iCIlTeasedl over thlat of the pie-

veriia 1 sealsoi, an11dthe wiilll veloeity ('all e qIuiite high-l.

I)uriuig 1954 the ai r telmllerature at the westerii eud of

(ane Ploidl vailed froii -12'C to 32.5?(. Air

teiiimperatures b)elolw (OT Wverl(lonllllllonly reco rdle(d

tlrllnollulOlt the vernal scasllli o(t 1954, the last such

lo1W tlill)tlati're lre bliog r llrdlll be(tweenl Many 25-28.

Noliixiui-iiiiii therniaoiiiters wr eti\'0~~~~Wei~illlllllillli h.lllIltlSstre kept ill

the water (Iduinng 19;54. The wildls attaiilled velocities

olt at lenst 740 ft/miii just over the Waiter surface.

T11e venial Seasoni (I .19.955 was i1ul11 illmOie placidl

tliaiil that lt the pvrecedlinlg vea.sl The air teiiiperatuies;

varie(d ftroit -3O to 30'(CC. There were few tinies

when the nir tetmperature fell below 0?C in 19.55,

the last time beiiig between MAylv10-14. The water

templeratulres(lduinig the saiiie year ralnge(l froin 6TC

to 260C in the verna'l season. The inaxiinnim Nvind

v(eh()eittvwvas 480 ft /mnin.

Throug-hout this stu(ly the terni mi-uIratioii will l)e

11se(l to Sinifv ". a.i 11iio1v eiit whicll involves

a jo)Urney(\inlto .1 (defillite area, and a return j(lle to

the 'nin Awhence the niovemIent arose (I lealp)e

19321). An emi-igration will l)e a imovemiient away froiil

(Cane Polnd, aild aI i liil-ngrtion will be a IiiovenIlent

iiito Cr.Iie Poind.

T he iiolCc Oi(] 0tiolon 0(1 t[I CmCO iy ((tilts. The aiii Im'd

activityrccle of. the (pi rsciiofs J)0J) olotioiiio i the

( i iil(e Pond area iicludes at least oiie migIratory

n(ovemluiemtallthouhall- aIninlulaIs (10 liot aIppearl. to

pa1rtici pate iII the 11iiiigatioii. Typica'ly, the emlimgra1-

tiOil takes plo ce (durilng the veiiial seasoil, the (e11-

gra1tiing turtles hleadiiig eastwar(l 011(1 \vestar(l dawav

from I(riieoin l(Tamnble 3). The hills rising 20-225in 11(1an iiore above the 11(11(surtace to the north and.

sout l)l ielule a iiy extemisive iiioVeliienlts iii these (Ii -

iectimi s. The aninias disperse emitlier hy tr xne'ling0

overla iid or biluOving throllugh the iiilet or onltlet.

Those going0 Overlaiid (uld stw-ard froimi (Crae Pond

prl)i()lbYs aire soon ftuiieled into the outlet by the

top)ogl~r.phy. 1 i1(lee(l, aIll turtles miiovill eastwanrd

tlllhoughl the outlet mlust first (c1rossanar111ow\ piece of

land, ahout 12 ini wide, hetore e iterimlig) the ()utlet

pro)per, for they will not pass thrlough the b)uried

111lvert which dri mis the ponud. Turitles nuigratillng

overland towa d(1sthe wvest iuiust travel across a 111i11i-

Ilmanunof 120 in of gransslan11dhefore aItta.iningt,South-

west Swa mop. Thlose which emnigra-te through the ill-

let lmeiuulin In water for miost,of the jonrlley to Soith-

west Swamp, but they first cross a road which is 5

]In wide separatiing C(lraie Ponid fromuuFishhook Marsh

and then cross amnilumuni of 40 iii of 1land to reaclh

Southwest Swanimp. -It is po;sible to travel between

the swapl) and the imaIrshwithout crossing such an ex-

tensive tlac( t of laid, but there is no (efinlite water

T~n.BE 83. NUIIIbelrs Of tull-tes uuCoving into aend out of (rnaie Pond during the various seasons. The seasons are

alblbreviate(l as follows: P, prevermal; V, vernal; Ac, aestival; Au, autumnal. The (lashes indicate periods when the

tralps were,not in

contiiualol)eration.

YEAR AND SEASON

1953 1954 1955 1957

P V Ae Au P V Ae Au P V V (part only)

Turtles Leaving Crane Pond byMoving:

West through the Inlet........ 16 37 0 0 2 277 12 175 12 61 35West Overland ............... 2 3 0 0 1 20 1 5 0 0 20East through the Outlet ....... - - 0 - - 9 6 6 0 15

East Overland.......... .. 0 0 0 0 0 4 1 0 0 0

Turtles Entering Crane Pond by

Moving:East Overland...........0..... 0 0 3 0 1 6 5 0 2West through the Outlet ....... - - 0 - - 6 15 7 0 2



April. 1939 POPULATION OF TlE IAINTED) TUIRTLl 121

li1111(ll1 betth.eel the tNN-' aireais. The turtles dlo notseeuu to t vol tIns ioute, for ione Ihtsveis beenleI

tiured(l osillg it. Itelee, aIII Illngra nts (lOss Somue bind.The 1lii! herl.of ( '1!/.11st,1 ios imveiielits througih the

illet dIin ellmilra tioii is shlowxnlinI Ta.ble 4. These(hiti (10 iiot 1e(1)reseiit the total iiumiiibei of iiidividual.tlrtle s a,.ssill tlllh()Ughl the illet, for Smiiie eliiiigrated

tllolmli1 ocl(e, milv to returnl to Crane Poi(l and thent ,vel n11pto the illet againI. lIi the vernl" seasoll of,1954, 18(5 r/5s(y00/ moved out o.t (ia iie I'oli(l twi(e,

2 three tinie.s a1inl I 1(111 tiilies. The iiioveiieiit imtaediii-in- the tall of 1954 will be coiisi(lerel laIter.

T a~m:4. rThe mimliwrl f(f (C FlSccl1/S eiiiigratiligwcstws.trd( tilroiugli tile inlet daring the spring of 1954 aiid1955. (O1l tihose Iates a re inlldiea.te(l on whlic tartlesW01 c,1.Iturled( inl thle ilde(t.

March 1954 1955 April 1954 1'95512 0) 1 2 15 7 0

14 0 2 17 12 I15 0 5 1X 0 l1S 2 01O )9 0 320 0 1 21 15 121 0 2 22 0 125 IO) 0 24 1 027 1 0 25 1 028 24 0 2 2 029.) 0( l1 29 2 030 0 ) 30) 0 18s1 0) 11

1\lavApril 1 4 0

1 1 5 12 1 02) ! <3 it) 14 1 0:8 0 15 1 0

4 O ) 21 1 0a

6 43 O) Jlneb(;) 0) 1 1 0)

9 3 6 5 2 O)IO) 1 2 6 1 011 22 (O I1) 2 012 6 3 21 .31: l7 4 22 1 014 23 (O

July-5 1 0

The miunmbersof niovemnents iln the inigration rapid-

ly reac.h aI peaik and theni (liminsh, but. the eniigra-tionl 111ay1VeonItillue ill (lesultorv fashion well into the

aestival period. These stra.ggt lers mtay be movingaibout ait raml(doIil within the lower areas of the Reserveso that it could be erroneous to consider then here,hut they aire iilelu(de(d for completeness.

The percentag-e of juveniles, adult niales, subadult

feiiiales, aid11(1aIult females emigrrating through the in-

let is preselited in Table 5. Juveiiiles are those ani-

mnlls vhich have anl ablbdominal laminar length less

thanl 2.0 (mo anid whose sex eainnot be readily deter-

lninedl. They are sexuailly mimnature. Adult mnales

a re those Chry/sem, i/,S with an afbdominal laininar

length of 2.0 em or moroe ahi(1 which have elongatedcehiws (onI the lorelimmibs (Sextoni, manusicript). Sub-

adolt f1emales are those p)-iilted turtles having an

a hdomlina1 hi la Vwhoselelltii is betweell 2.0 and 2.9(i Cll11(1which (1o iiot have eioniigated (laws. Thev are5exua li iiiii.atu Fe. Adlit feiiia les are those turtles

ill Nviliiel the length of the ahdoiiiia 1 hiiiiiial is gr1e1ter

tim21i 2.9 eiim 11(1wnichi (10 iiot hita (e elonateil ela whs.

hlie 1ll:1jolitN of theseate11 Sexuatlyllv itiature. As i

1)si toi eoiiomparison the 756 inidividuail (Chrlscm (/

knowii to hbe alive dIuring the .1953 growillg sea2son1

(FAzig. .3) eoiisisted of 2.8% ,juvei lies, 20.3% slba(iuitteiiiaides, 20.2)6`c eiiaultteim-f1(s , anid 26.7C/,d dult im-des

oiista uit cheek was iiot nillait:it1(led over the emiiiiral-

tioi duiriing 1953 aild 1957 so thait the data tfoi these

two yea(1rs ale incomill)ete. 1li the spr nigo of 195419.3%, of the eliigtaiis were't juveniles, 21 .4 suill)-

a iliiit teiiia21les, ')29.(i%("aidiilt f les a iid2 9.6)(j a (hltiiiaies. InI 1955 11 of the emioii2graits wvere juveliiles,

2)1.9C`j, sub~~adult females 34.2(/)/' tIdult f-des 111d32.9%/' atduilt i.iiles. It call, be seen that iewer iiUVe-

iii (elligra te tihmii oiie woulld exp)ect oil the basis of

('hai111ee, l)llt iliiore aIllilt telles an: d11 iial-es ellmiigrate.rl1lie pIiiie italeo of slilubidult Ftei ales ill the (iltil i(1953 plolllatioil aiiil ili the pl)piiiiationi of eiiiigaiitsis all)1bt the saiiie.

Thlie(dita fio Tab.1e 5 iniidieate that a1 .hii-rge o-

ti(oll of the si1iillerl turtles ieii iaiiis in ( a11ne Ponidwhile the 1:Iagelr illflividulals of both 5seXes elio-inate.

Sever'11 iollieetiis W(e'e( 111a(1deill the 1)011 (1111dur

peliols of hea.1vy e(liiri'g1tioil to deteliiile the stinle-tiiie of the( residuia,1l J)i)f)lopitiioii. I)uriig Api-il 9,1953 tlhere \va s an11 elij-orati on of 27 (Chrisc hlqs id

wliic 3.7(4 were juveniles, 14.8%6<subaldit fenaul1es,25.9).( a duit teiialesl , a1iid 5.6((/ a(dllt iiia es. ()hi

thle Sa ii(e (hiy 11 pi11 iitedl turtles w(erIe Iletted wNittlilltille pt ll, amil thlese cioisistetl of 72.7%j' uvelliles,9.1 % suba dult feiiilesx, andid .2% a(luitteamt ies.I)uriiig A pril 6 and 7, 1954, 11 ) turtles were eanlglit

ill the iiilet a1d(1 14 ill tillp loldll. The emlli-ra tOi-v

groN)up) comlsistedl oft 14.3% juveniles, 19.6%. subaldultfeiiales, .34.86%Vladlult fteiiales, 11(1n31.3%1 *(allult 111iides.

The resi (lelits were c l)opsed(of 71 .4%f ,juvemiiles,7.1 subad(multfe'males, and 21.5%/, a(lult feiales.Even though the lnulmliers (If turtles ca1ptured withlii

the ponid1 is iiall, the results seeiii to (orrohorate thebelief that the younger turtles (d(onot tenld to elili-grate .

There is also a tenldellen for iiiore females to enlli-g-rate than niales. Whereals the sex ratio of the adlultaiiiimals in the 1953 population of 756 Chryserntys was

0.76 Y Y /1.0( ,that (of adults emigrating through theinlet during the spring of 1954 was 1.0) Y /1.0 Sa8(d that for the spring of 1955 is also 1.0 Y Y /1.0 .

hfence, it would appear that although prol)ortionlatelymore adlult (Chryseiails are among the emigrating,

group than One wouldl expect, the two sexes responl(ddilfereitly. The (chnge in the sex ratio is evidentlybroug-ht about by the increased iiuiiiber of adultfemiiales which eniigrate.

The relative abundance of each of these four

classes, juveniles, subadult felnales, adult feminales;,and males, didmnot remain constant throughout theeiiiigratorv period (Table 6). Iin 1954 the adult



129 OGWEN J. SEXTON Ecological MonographsOWEN J. SEXTON y~~~~~~~~~~ol29. No. 2

TABE 5. (CompositioII of the total iumber of painted turtles emingrating through the inlet.

Mar. 21-May 27 Mar. 18-May 31 Oct. 3-Nov. 19 Mar. 12-Apr. 30 Apr. 17-211953 1954 1954 1955 1957

No. No. e No. No. % No. //o

Juveniles. .. . 3 5.7 54 19.3 35 19.9 8 11.0 1 3.0

Males .. . 24 45.3 83 29.6 53 30.1 24 32.9 15 45.4Subadult Females 8 15.1 60 21.4 43 24.4 16 21.9 4 12.1Adult Females. 18 33.9 83 29.6 45 25.6 25 34.2 13 39.4

Total .. . 53 100.0 280 99.9 176 100.0 73 100.0 33 99.9

TABLE 6. (Coiposition of the emigrants nioving west-.ird through the inl1(t.

COMPO- ITION OF MIGRANTS IN

Date in Total1954 Subad. No.

Juv. Q

Mar. 25.. . 10.0 20.0 20.0 50.0 10Mar. 28 4.2 41.7 8.3 45.8 24Apr. 6. . 7.0 44.2 11.6 37.2 43Apr. 7 . 18.8 23.3 24.6 33.3 69Apr. 11 . 9.1 18.2 45.4 27.3 22Apr. 13 . 35.3 11.8 29.4 23.5 17Apr. 14 . 26.1 21.7 30.4 21.8 23Apr. 17 . 41.7 33.3 16.7 8.3 12Apr. 21 66.7 13.3 13.3 6.7 15Oct. 12 . 25.4 27.0 14.3 33.3 63Oct. 13. 25.8 29.0 29.0 16.2 31oct. 14 . 6.3 50.0 25.0 18.7 16oct. 23 (0.0 9.0 54.6 36.4 11Nov. 19. 27.3 18.1 27.3 27.3 11

fenuuales were the first to reach their peak of abun-

ulainee, relatively early ill the eiuigration. The males

attaiule(l their g'reatest relative abun(lanee shortly

aifterwar(ds, n11(1the niuales were tollowed( by the sub-

ad(1ult teiiiales which reached a uuia1iUIui on APril 11.

rpe pereueitag(e of juveniles ainiolng the euinigrnits was

erratie durii-g thie (elly Ilart of the einigr ation but

iiCre11asedl greatly towar(ls its e(nd(. It is interesting

to note thlat tie seqjueince of these four classes ill endi-

giatioii is the saniencs the (lescending order of aibun-

(lanec of thiese ftoir (lasses ill the overall make-ul) of

tle enill-(laInts. That is, the a(lult females are the

fitSt to eililgate in numibers, and relaltively morefeniules elntigrate thian (1o ineiubers of any other class.

The relitive abulndalnee ot these saine four classes

a nuoign the eluuigrailts leaving (C1ane Pond bv other

ro0ites is )Iesenltd(l ill Table 7. tnfortunately, these

(lata alre tenlious sinlc( thie aisolute nuiubers passing

out of (iaCre Pond throughli thefise other egresses are

low . Even so, it (a1ppel uIs lthat the uveniles d(1 Ilot

leave thie 1)0on(1 by m)oving through the outlet or by

going overlai(l, n111(1it apl)nlrs that relatively high

p)roportiOms of a(lult 1ma -fles nil feles (,comparedto the a niiuals alive in 19c53, Fig. 3) (lo utilize these

othier p)antis. 'The relative Abun(lanee of the subadult

felIlales varies aI grieat deal vear to year ain(l exit to

exit.

En r iron ln n tol1 e(ntn res (If C rnine Poda(1 d11(1sii rromtnd-

ing aereas datring the vernal emigrationt. There is

little surface vegetation present in Crane Pond during

TABILE 7. The composition of emigrants leaving

(Cranle Poll(d via various routes.

West West West Eastthrough West through West through throughthe inlet overland the inlet overland the inlet the out-

let

1954 1954 1957 1957 1955 1955

Total number of turtles 280 21 33 20 73 15

Percent Juveniles. 19.3 4.9 3.0 5.0 11.0 13.3

Percent Subadult

Females.......... 21.4 33.3 12.1 15.0 21.9 26.7

Percent Adult Females 29.6 33.3 39.4 45.0 34.2 20.0

Percent Adult Males.. 29.6 28.5 45.4 35.0 32.9 40.0

the vernial seasoil, for Nuphar (aLdreiaais the olily

species which grows to the surface liuueh before the

enAdn(of the spring. This species was first aj )j)alrenltonl the water about April 14, 1954 anld Marecl 9, 1955.

The majority of the plants reachetl the surlface and

fille(l ill imost of the outline of each lily be(l l)v May

6, 19.t54 aid(l April 222, 1.955. Thlis samie (colIditioll,

lack of suiftace vegetatioil, dloes ilot prevail ill South-

westtSwam11p (Illg the Ver1l: seasoll. IHee the

area colltalilled withil the co0lifIles of the m1oont re-

sen bles Ctmauie Ponl, but the shallow a1reats oft the

Swainm) supp)ort a relatively high corcenltmlatioll of

surfa'ce vegetaItioll, including such philits as Lcc)s,

Oei,.'o i(led.s, )p(irgaoa ilam ea Ci.jarpi)a _.1isi)i t)a i viale,

'A qittirioa ltijlia , Sp)irodela p)ol!/rl 'a anl Leia no

trisalc(a. Durling the verlial seaIsoit IllalilY of these1h)11its, especially the gra(mminoids, (o llot projectat1bove

the waIterl. Rlathler, tile listal .ttlds of the plaits., float

111l)01 tle suifa( cc, torm ing a imaIt. Sp1irod elp )OlI-

rb La hebcomes eitaligled( il this nauit ami1i l)ovitle s;

addi tima I (cover.

A temperaiture giradienit exists withini Cra,me P'on(d.

Time thler llId va.1na1'tionls of the illel(t currellt w\vere (0omm-

1)p1ittI to those re(o'(rded(l ait other statiolns throughout

the Poinld. I)uringii the prevem'ial alid vermiad1 sea sons

a mmI1liaxmmmllm-mnimiiinumntherilt)lleter was place(d Ill the

waltel at e(1ach of the followillng statioms time ilnlet

stakes 57, 13, 32, and '26 (Fig. 2). 1)urnimg this

peli)(1O the i ildet reg-istere( the greatest (lifefmemce be-tweemll illmax1i mi111aimd ilii nltum temllp)eratures ill 15)

of 24 timmies. Il. 5 of' the remnalinin- 9 cases, the dif-



April, 1959 POPULATION OF THE PAINTED TURTLE 12.3

terence obtained at the inlet was as great as that

obtained elsewhere so that there were only four daysin which the differenec between the two extreme

temperatures at the inlet was less than that obtained-at other points in the Pon(l. Evidently, the shallower

water in Fishhook MNlarshis heated imore quickly(luring the day and cools more rapidly during the

night. As this water flows into Crane Pond a thermcalgrladient is established which is reversible, for theinlet current is wariner than the water in Crane Pondduring parts of the (lay but cooler at night.

In additioii, the difference between maxiimumnand

minimum values recorded at stake 57 was greater

than the difference for similar recordings at stake 13

a total of 11 timues out of a possible 14. This indi-

cates that at least the western third of the Pond is

divided thermally. The inlet (current has the muost

variable templlperature, and the water off stake 57 is

less variable than that in the inlet but more so than

that off stake 13.Fluorescein a1( lcrvstal violet added to the inlet

current in(licate(l that the water passing through the

mimainchannel of the inlet bifurcated into two branches

soon after leaving the SalixJ zone which delimnits the

mouth of the inlet. One branch continues eastward

into Crane P0on(1or mOves parallel to the north shore.

The (listance over which this water mnass will retain

its integrity within Crane Pond is not known, for the

(lyes become dissipated too quickly. However, the

lve is evident for a( distance of 10 mnfroin the inlet

mouth. The seconid branch miade a sharp turn south-

ward and continued about 3 muoff the western shore

for '20-25 m.The influence of' wilter temnpj)eratureand current on

emigration. (Chrilsemils is primarily a diurnlal ani-

ial, and emigration is restricted to the daylight hours

(Table 8). The (lata in Table 8 indicate that the

dlaily peak in emusigration (luring the vernal season,

measured in number of turtles emigrating per hr,

TABIJE8. The hourly variation, in miumberof Chry-c/S1 ms iemigrating per hour, omithose days durinlg 1954 01

which 15 or moore Chrysemys nlove(1 westeward through

the Crane Pond inlet. The questiomi marks refer to data

for -which tile rate camimiot he accurately deterniied

;although somue emimigrationi occurre(d.

Mar. Apr. Apr. Apr. Apt. Apr. Apr. Oct. Oct. Oct.Time in hours 28 6 7 11 13 14 21 12 13 14

6- 7 0.0 0.0 ? ?

7- S ....... ? 2.7 2.0 ? 3.0 2.3

8- 9......... ? 3.0 2.7 2.0 0.4 ? 3.0 2.3

9-10 ......... 1.3 3.0 ? 2.7 1.7 0.4 8.5 1.0 2.3

10-11 ......... 1.3 0.5 1.0 2.2 1.7 0.4 8.5 2.0 1.0

11-12......... 0.0 1.3 0.5 1.0 2.2 1.7 0.4 10.3 2.0 1.0

12-13......... 9.5 10.0 11.5 7.0 2.2 3.2 0.4 10.3 8.5 1.0

13-14.. . 9.5 10.0 11.5 7.0 2.2 3.2 2.0 10.3 8.5 1.0

14-15 .... 2.0 10.0 27.0 3.0 0.0 3.2 5.0 0.4 ? ?

15-16.. .. 1.5 7.0 3.0 0.0 3.2 5.0 0.4

16-1......... 1.5 0.3 3.0 0.3 0.0 0.4

17-18......... 0.0 0.3 0.0 0.3 0.418-19.... ..... 0.3 0.3 0.4

19-20......... 0.0 0.0 0.0

occurred most frequently between 12 noon and 3:00

pmll.

Little or no emigration took place unless the water

temperature in the inlet rose above a certain critical

level. This level was 7?C in 1954 an(l 6?C in 1955.

However, 8$C appears to be the lowest water teml)era-

ture at which Chrysemys migrate in numbers (Table

9). The discrepancy between cloacal teltl)eratule

TABLE 9. Relationship l)etweelL the nuImi)er of enmi-

granits moving through the inllet ai1(1 the teillp)erastu ie

of water at the inlet.

Inlet Water Temperature in ?(

5 6 7 8 9 10 11 12 13 14 15 16 17 18 19| 20 and over

Number of Turtles

Spring 1954. 0 0 2 31 0 17 1 11 5 36 0 1 50 0 0 0

Fall 1954........... 2 o2 2 2 9 011 8 0 2 12 28 21 0 0

Spring 1955 ......... 0 2 2 4 5 2 1 12 2 11 ( 21 1 3

and the teisiperature of the itiedium whichl was noticed

during the prevernal season (Table 2) was not as

extreme in the emigrating Chrysernys (Table 10). -No

turtle captured in the inlet had a cloacal temperature

below 8.4?C. These data again indicate that these

is a threshold, approximately 8?C, below which ena-

gration does not occur.

TABLE 1(0. Conitrasts ill temperature betweeni imidi-

vidulal emigrating Chrysemys al1id surroumIdisg medium.

Asterisks idl(licate animals which had beeim ini tie sir.

Water Temperature of the Cloacal Temperature of theInlet ?C Turtles ?C

6 8.7, 8.87 8.98 8.4, 8.68 8.5, 9.0

10 11.311 11.711 11.812 13.413 14.413 13.2, 14.2, 14.3, 15.0,

15.2, 21.2*

14 14.614 16.115 15.715.5 15.8, 15.9, 15.9, 16.115.5 16.2, 16.7, 27.0*15.5 16.115.5 16.018 18.719 21.020.5 21.5

Table 11 shows that certain telslperatures niust

be attained in both the inlet water mass and the waterwithin Crane 1Pond( before entigratiom. will occur.

During the short l)eriod in which emigration wasstudied in 1957 one maxiu-mn -ailminniuss thermsomuieter

was placed in the inlet ancl another just benseath the



124 ( ) Wl<.N .r. S ExrrON Ecological Monograplis124 ~~~~~~~~~~OWE:NJ. SEXTON IVol. 29, No.2

sulrface of tlhe water wvithin Crane Pond at a point

48 in east of the inilet month anll 15 in off stake 9.

Ihe water 'as ; i(57 ledeep at this position. Chrgq-

.Pemi li(1diot eiiiigrate in numbers uniti.1 both the

Iiiiillil 111d(Iiiaxillial tenllwIratures weren bove 9-1()0C

ait bothphila e-s.

T.uIIK II. The muiiiher of emigrants aiid the mininnal

.11d11a 11xillal water telllmperatuies ill the ildet 1lld1ill (ilaiie

Po011( hetweeii April 15 a1u1( April 20, 1957. A naxinxiuni-

millimiiuiii tlieriiioilieter was pIlace(l ill the ililet for this

elitile period, indl aiiotlher wa'S sAitnated. just leatilhtl the

surf fwe of the wnatei at aI poi t iii ('ra iie Pond 48 ii

wvest of the inilet Iiioutit.

WATER TEMPERATURES 0C NUMBER OFEMIGRANTS

| Iilet Crane PoIid West WestDate -- through Over-

Max. Miin. Max. Miii. Inlet land

April 15. 14 : 3 11 2 0 0April I . 10 5 1(0 6 0 0April 17 1 1 8 10.5 8 0 0April 18.. 12 9 12 9 2 0April 19. . 19 10 17 10 12 -13April 20( 21 15 2 0 1_4 l_

Fi<li ''e 4 illlusrates the reversal of the theriiial

i1(li'lilt wi thiini til westeiii a1 11t of C(Ial |ie Ponld.

The ulilrXv tIl thil tepillpera turie 1o1 till' ilelet raittl 15(1s

111101t' steplyl thii that olf till' \\ltl o1ff staike 157 oi

til l(o11er 11os05'1 the aittei hun iig till 111011111111.

ElIligiatioll is llaexie'st wiiell till' culive1 o1 till niet

teiii 1111r1tiil s ablove thiat otI the 1)1ond1 t pli1)tl iatUl.

e'lia s)s it iS thiis 1)11111111i i 11ll IoI t 111111111 Ieve Isiliility

Whicli ii Ilelulnts for till 1)ank in the lill (vel oIfI lill-

iaIti} 111 (U11111riim ill the a ttellIooll, fo i flw turtle.s;

mlovt' Olit bef'ort' thet tt'lplrnt'lxirel po0h11 ityt }11s, bet't

17_

'5 -

13 -

N M N M N M N M N M N M wHOUR

w / 1M.-s

I 2 11 5 I0 2 wM'GRANT

Fim,. 4. R~elatioiishiip (If the water temperature of the

iniiet (solidl line ) and that of Crane Poiid (d~ashed, line),

as11rlPlreseiltell hy the water off stake 57, to the num-1hCr (If eiiigraints pIassinig up to the inlet. N is noon

a1-111dM~is midlnighit. The danfti are froiii the spring of

1955.

reverse(l, 11(11ln11d (1()Idot exit before it is well es-

tbilishe(d.

WXhile the exodus of the (Cbrl/sC/i//s is corre'ited

with (ertatill temllll)peatUre ('a ('teristics oft the ValliouS

Wat'1tei' lmssesT there are inl(Iicltionis thaif the crlIlelnt

itself ix (-I 1ositive force iniflueni1nc t(lli-i ItioB. N.

11188 (Islep tUt're of turtlest tromi the Po1 1was ever

()obsl-ere (xce})t during plios when wnter wv1asflow-

iII- into the Pond tfrom0 thle test. Su1cvh occasliolls

occiurtedl uriing the springs oft 195:3, 1954, 1955,.1957 (1lrinill the fall of I1954. Ac t.l.lll!, thev Ull-

(lOubted(ly take place eac(h sprlling n(1iiit those autuiiins

inll ii(h ate(lite tnters X(r lle Pomld. ID)lll il tleh It-

ter' pnrit oft April, 19 55, the inllet (clltrelt was blocked(

to see if therew( S (a111 ('1a111ne ill tIe lIuIIIhes of(71/F/'scml/s emigl-ratinog 01 if thci'e wnSal lay (lillli ilitiOii

ill thea (tiVitv ot, the all111 ils a bout the inlt. Illemlotlh.

AMost (4 the tinlte ti (Ullrent eould not IW sto)pped,but it x-aIs reduce(d to at least hnlf speed. Severall

ti iies theretv'ws no flow of Avatei throu11g the inlet

It (a111. These experimllents Wtere vel irlyoiiliisi te

silnce most ot theallt liaxlIls had( alIeadv (Itt (rnle 1Polhd

so tfint too few tllltles Wtr' (cla)tulred to iiake a

generat' .lI( iz(t)11t . lI oxtever, shor tly- a ter the rI-

mlov:1I of the (la I11on April 16, there WalS 8111 inCr(ease

ill the a iulliit (t aIctivitv about tle itoutli of the iII-

let aitiltOUil- 11104 of thie tulrtles s(Ieed(I to he seekillg

h.lskiill Sites. Trle eXperlimllelntIavs rep)e ted1 )ii April21, -19571. rTh1is (IaV Il( Ibe })ltbnpeceded by two (Iays Oil

whlihll fa ilbtv (XtellsiVe elllira-Iti(m1 Ila (1doccl ied. Tlhe

('lille'llt ba ciked( at 8 :20 a 011 the 21st. Tilet'

d.Ia111 dhid IlOt inllttlfel(c ithl tile 1llOvemllelt ot0 the a1l-

11 1Sillto the tir p. No (Ih/rye is wvere ill tile illlet;

tia p at thl, tillte; tile Awater teuupeatuve NNa8s 15 (C

('eltajill 'V a (le'(jI te for (illnigra tiOII. No turitlhs were

found ill the tia p at 10 :35 nll ( Iwatei tetll peratuie -

177 ) 1101 at 11 :45 nill (Nwater tell)tlrtllle= IC(1).

Thre(l( Wele 4 Ch rposeiimis sulnnlling at the louth ol tie

inlet a ld 6 ill the water oft the iliet aIt this laltter

tillt. rhe block was reuoved(l nt 12 :3() lil ( water

tetm)rlature = C19 ) anld rechelekei at 1 :00p)(I)), but

there Wtlte no turtles ill the trap. One (71,ryisecmys wtis

(81)tul(1 tat 1J:130 pill (water t plleltatule = 20.5 C),

an EmyIJs bl(uidyi fit 2 :30 1)1i1 and a second011( ry-

sennsa at 3 :45 pin (water telmlp(r.ittlrle - __ . The

(lataI tare XtlremlleIV illegl, rbut theyv at least arce inkeeping- with the idea that the clurlenlt itself is Ifatactot

in (iriectihg the emi-atillg Chrlvisemls to IlnoVe west-

walrd.

The extent of the disper(w l mol(olmenlts. Tultless fTol

all parts of CraIe Pond enlti-late through the inlet,

:1ald the dIlrleellUlhllll (11re:t (listanlee a turtle Illust travel.

withiii the pond before reaching the inlet varies fromt

0. 111 if the anlllhil i's Cat the inlet Illouth to 315 1i1if it

is At the etastrern (1 of (CraIne Pond. Ir 195-4 ?

Chry/se/m/s wCeIre(capture(d a total of '27 tillln8 in CranePond hefore they were again captured while cinigrtat-iIItg through the illet. The nIllinill di icet l1(li) dis-

tanlce between the site (f original capture tand theinlet mouth was 41 i11, the 1im-1?iXmum315) ill, the aver-

age 15) ll. Trhe shortest time intervnl between the



April. 1959 POPULATION OF THEPAINTEDTURTLE 1

orlgitiotl ajptUre wvithiti C(atie Ponid and the captureill the tilet wa^s 3 hours nil 15 iminutes (the tinilltullm

tIm-a) (distalice traVerse(l was 120 il1), the lotig'est spatn

was 4.3 (days (two cases: the (listaite tlaverse'( was

65 III ill otie itistaitic anid 295 i1 ill the other), anid the

avelage ititeival was 16.5) (lays.

Thelt is int) evideiiee thalt the plainitedlturtles closest

to the iHilet iOUth artae the first to etitigrate. Three

p)ailtted tllrtles were capitUrel two or titore tiIIties ill

(Ciatie Ioidl prirl to their etlig-ratiomi. All three had(I

nioved awayv tfrot the tilet rather thean imoving di-

twesttl to thte itilet. Il (l(lditioll, xvhelt testedl for a iiv

(otelatsiotil eteet\ itllheti the two va riables, niuniui

tia (Plitsta(te l)etweetll thel site of the orlginilal cC1)tpuiewitliji (talle Potllol aiol the illet touth an1ld the titte

ititrtvi I hetweetll the orlgiitialI (a.pture a llot the itilet

(aiptute, were showit to be itimlependlelit with r - 0.24

atio1l N-= ,

Tiihe iau att se"as into which Ch 105s(e0 /s5 jourlltes

firotii (i 1ltllt aIte tot the xvest atith southwx-est a iold

tot thle ea.1stott (Otata Pottl. Southwest Swaitip sul)-

po its titatiV itihiolltadls ot, this species, toiitst if titetllfrtoti (t0 tie Pond. Thlis ltiecessitxtte's a jouittev ott at

leaist 120 ii to iealih Sotuthwest \Sva npl) atidl a111toe-

t'oitit ( tatimothler 280 ito tot teach the titiost dista,ut

,ollt ol thle Sva tip. Other Ohrittse(!,ys, p)teviouislytor ke(l illt Crtatie Pontid, have beent reca iptnte ill the'

I)itelh, 1,0SO( ii(llowlistrea i tfrotm CratiellPtiol a.1ild tin

a hillsi'de eaIst of Ca1ttail,I Marsh, about 1 000 II dowI-

stteat11i trott (tatie Pottiol.

Tlie o1lispetsalofX,

CitP//seat/ s ftot i (iaate Potld

seettsI to he lillited tot Soutlhlst S wait,)p, Fishhook

iNIalni4, thle D)itech, atiol Cattail MLarsIhs I )urilln the

SUtIttie(t' of 1957 foulr b)o(lies otf water peripieral to

the (i tie lotlid arei, RIiddetl Laike, Islaln Ponld,

ButtlloPid1 atlld Sayl lake (Fig.. 1), were ilivestigateol

to see it aill\v ttarkeol animt-ils frotti the Cralne Poitoll

a tea lotIld ttoved itito thetti. Althiouglh the fi st threc

ata'11 are Withlill the saille(Itue lit"iagesvstetii as (t11Ittie

Potld. tlere is nlo dlirect water h t li cl cotlillects

tlietli to (tatiePotdl. D)uring periods of highlipie-

(i i tatioti watet ftrot Hiddetn Lake anld Burt Pond

flow.s itito the l)itcli after passing through extetisive

tatslhes ati(lndswattpl)s. Notie of the 17 COhroilsettot

(altlutel ill IHiddentiLake, 12 juveniles, 3 su.ad(lult

tetlta1's, 1 aldult feltiale at(lld1 adult male, were tti-1-mals whlic(hi lot )eet timarked l)ieviously. Nor were

tillv of the 18 p)ainte(l turtles collected1 ill Burt ati(l

Ishlatd Potids from Crat-ie Pon(l. These 18 attnimals

etisistedl of 6 juvetniles, 2 subadult females, 7 aldult

feutiales, atd( 3 ad(lltlt mtiales. Savl Lake is 40() ll

soUtthwest of Southwest SWallltp anld separatedl trotti

it hv a toad anh by (ldrygtound. The total dlistatice

l)etweeii Crane Ponld anld Sayl Lake is ,about 800 tll.

Notie of the 34 Chrqlsenils captured iii S.-ayl Lake

were reca ptures from the cetitral population.

A(tilities of the C(hrxsenoos remoining within Crane

IFo)I(. ()tldv a few turtles remail within Cratne PotId

for the entilte veliatl seasoti. Counts of turtles weretitatle iii the spring of 1.954 to give some itndicatiomn

of their relative abutd(lance itt Crane Potid in ( Otl-

trast to their abundamice itt the northern one-fifth of

Southwest Swanip. On May 1, 11 ChrYsemys were

coUlite(d in the Swamiip and only 1. in the Pond; Mayv

6, S ill the SwaIIIp anrd 0 in the Pond; May 9, 3 in

the Swamiip and(l in the Pon(l; May 1-3, 22 ii the

Swa1111)-and 4 in the Pond.

It became evi(lent that the (listribution of Chrq111-S(?sc l/.q ent aingin the Pn11(1 was correlateti with

certaili envirotimentat-l factors. Onl April 22, 1955, aI

Iiiap of the surlfaIce vegetation of the pond wa-s (Ira n,

a i(l onl April 23 the location of aIll of the Ohrilyse qsobservedl iII the p)o0d1( XliS superimlposed ()io this bac-k-

g,1r1oumidmai-lj1 ( Fig. 5 ) .The lcatiomi ot pa imited

turtles (captured or' observed dlrin' Mayx 1953 was

also recoilded on tills nap. III comiiparii n, the (listribu-

tioll of the anli tails (lulrinlg.these two vernal'l1seasomis,it hecOities a1pp)al'.e1t thaIt there a.1re four aIrea1s. ()of

turtle conicenltra tion0 (conitoonolto the two utitaps. The

use of these tonui areas by (Ci 'ylesiolis aippears to be

relted to the fact that these arealrs Provide the onlly

sunuting sites ait this tiutie of year. One sectionl, 1i-

ceate(dbv the fallen trees, haIlssshifted sllighltly over the

two yea ll perliod. Inl -195 3 there wN-ere only ai few

fallen liuiibs which xx'ler eXposed ellough1 to p)rovi(lesunu11inig0(areats. D)ulioig the spring of 1954 two largeoak trees topp)led into the waiter, and thiese f)m'ied(

more de-sira)le sunllilng' places. A second area used

by the Chi-'qsemoos is the Thipha bed. Tle ciuui(l)sJ'

dea(i Typhi pr'ojeetioig ab(ove the water surface pro()-

vided pl)atformiis suitalble for sunning. The dIeadl

.Salil in the mouth of the inlet is the third allerl of

conceuitration. rthe, fourth arei, inI the xest sectiOli

of' the p)oid, is the bedIs of NAfooh0' (ad1(r(a whose

floatillg leavesplr)ovidle

sunning stttions. In1,955,the turtles wNere alsssoeiated with the mat;s of'

filamtietitous algaie which gre\x' alongside ai1(l within,

thlei I)ltcles of Nolphor. It is noticeable that few

C(hryscmlss were founl in those alerts lackilln, sUnrIng

sites. i)urin, the vernal season the banks X\'ere nlot

used for sunning ais frequently as the' wx'ere dur1ing

the pl'eve'rdal sea soli.

Thie noiniuni (listalices between falrthest lpointsof (ca-ipture were iiieasured for Chrj'lseols calptnlreltwo or itiore tiues withini Crane I'ond during the late

vernail seasomis of 1953 and 1954. The limiting (lates

were airbitratrily set at April 15 an(ld May 31 so that

tiovetentts; (lue to eiiiigration could be moore or lesseliminmate(d. Nine painted turtles were caltured twoor moore times during this 6-wks period in 1953; the

distances raug-ed from 0 Im to 301 ill aftnd aiveraoged

144 ill. Eight turtles were collectel dulring the same

period in 19.54; the range of variation was about the

samiae as in the previous year, I ill to 279 ill, but the

niverrlge was onlly 63 ill. Both (If these aiveraiges are

higher than those observed for the prevernal season.

Chrysemiys begins to feed when the teniperature

of the water rises above' 1j50C. Anim,-als were ob-

served eritimig in Crtrne P0n(1 at temiiperatnres of 16CC

and(h17?C. Turtles froiti areas wNithin 1(0 kill of the

George Reserve were kept in captivity ill a large1)001 ul1(leil fairly miatural conditiomis. Fee(dinmg be-

"nite eCxtrellely (desultorv as the falling' teniweratture

rapl)Ioaehed 15?C.



126 OWEN J. SEXTON Ecological MonographsVol. 29, No. 2

A.

c23

FALLEN

FALLEN / TREES

TREES.

NUPHAROD2NPA

0 26SCALE INM.

A. MAY, 1953 ALI B. APRIL, 1955 SAI

FIG. 5. location (circles) of all individual Chrysemys observed in Crane Pond ill May, 1953 and April,1955. Each circle represents a single individual except as indicated by the attached numbers.

THE AESTIVAI1SEASON

This period of the year extends from June 1

until August 31, although there may be a leeway of

one or two weeks in either direction. As iiientioned

previously, most of the aquatic plants which are im-

portant to the painted turtles as loci of activity have

reached the surface by June 1. The vegetation con-

tinues to increase inl weight as the season progresses

until the biomass of the air-dried non-planktonic vege-

tation averages at least 1300 kg per acre by amid-July.

The air and water temimperatures attain their annual

imaximummiduring this season. In 1954 the air tein-

perature at stake 57 varied fromt a minimum of 20C

to a mnaximumimof 35TC during this period. The

water temperatures are less extreme. In 1954 the

minimum water temperature registered 13TC, the

maaximumii29TC. In 1957 the temperature of the sur-

face water (shaded) ranged from 17TC to 33TC while

the temperature on the bottom of the pond in water

53-65 eIm deep varied fromn18C to 31TC. Thus, the

water temperature rarely falls below 15TC during the

aestival season. This is the temperature at which

Chrysemys begin to feed. Renewed growth of the

animals is first noted during the first week or two of

the aestival season and continues until late August.Shedding of the lamiminaeor scutes also occurs during

this time of the year.

The activities of the painted turtles during this

season are characterized by dispersal amovements from

one body of water to another and by movements from

areas of one vegetation type to another within a single

pond as the water depthfluctuates and the nature of

the surface vegetation changes.Spatial reorganization of the population. There is

no mimassiliinioratiomi of Chrysernys which can comimpare

in intensity with the emigration, for the animals

gradually filter baek into the pond from outlying

areas. If one assumes that the first aestival recapturein Crane Pond of a known vernal emigrant indicates

the latest date by whieh that individual returned to

Crane Pond, one ean obtain sonme evidence of the in-

tensity and duration of the immigratorv movement.The dates on whieh known emiigrants were reeap-

tured after returning to the pond indieate that immi-

gration is a steady process whieh begins during the

emliglation period itself and extends into fall (Figure

6). It is also indicated that the height of the inmi-

gration probably occurred during the latter half of

July and miost of August in 1954. There is a three-

week period in late August and early September for

which there are no data.

The entire nmigratory cycle in ChriJsemjs., then,

consists of a sharply peaked movement out of the

pond during the spring (occasionally the fall) and a

gradual movement back into the pond in the summer.

The peak in the former is very pronounced and

occurs soon after the start of the exodus. There is

no distinct peak in numbers of returning animals.

Table 3 shows the number of animals caught enter-

ing or leaving the pond during the course of the

study. It can easily be seen that most of the animals

caught in the spring are leaving the area, while a

higher proportion of those captured during the sum-

mimera-re returning. This is true not only for the

inlet but also for the outlet. Actually the six ammimnals

miovirmg eastward out of Crane Pond in the aestival

season of 1954 and ten of thetwelve turtles leavingvia the inlet that samie season were stragglers frommi

the vernal emigration. These sixteen turtles left dur-

ing the first three weeks of June. In the vernal



AI)ril. 1959 POPULATION OF TIHE PAINTED TURTLE 127

NUMBER RECAPTURED EMIGRANTS

4/14-4/20

5/26-6/1

0~~~~~~~~~~~~~~~~~~~~~~

" 6/30-7/6

7/28-8/3

9/22-9/28

FIG. 6. The return of vernal emigrants to Crane

Po0n(d (lurilig the summtuer of 1954. The ord(inate repre-

snIts the Inuiiiber of emigrants recapltured in CraIIe Poi1(1after they l1l(l emigr-ited, 1ind the abscissa the week

(lurilig which aIIy emiiigranIt was first recapIture(l in the

po01(. No collectiiig was done from August 25 until

Septemiiber16.

season of 1954 thle greater number of C(hri/sem/s

moviii- tlfiougli the outlet are headed eastward awav

firoi thie pond. II the aestival perio(I the treLId

tlhrough1the outlet is reversed, for itiost of the painte(1turtles are now iliovinlg wetward into the pon(l.

Response of' tie p)oulatiotn to regetation (chan>ges.

I)urimn the afestival season of 1954 three censusesNvere 11d(le of the Chr/j semnqls in Crane Pond. ThereWere ')2) ill(lividual Ch ryjsemns (counte( on June 1(l1i~ltt the fi st celisus, 71 oII June 22 during theSecond cemsus,la(nd 152 oni August 13 (luring the final(Celsus. This inCrTease in numbhers of turtles as the

suIIIIIIer proglressed also ili(licates that turtles returi

to Cra iie I'(:l(l (luriLng the aestival period.The census of Juiie 1 (lid iiot illclu(le iapping of

thie a(etual )ositi on of each ill(livi(lual, but 3 were

,suiiiiiii On exPose(l branches, vwere swi lliing inopen Water, and 17 were associated with ql(1ultieve-ebttio((, iiiostl1 R(Jinfc ifllfls lonytirostris, Potamin o-

flo~toll (o istilssWs,andl~I). ~trictil olin s.r1iioI to tlhe Se(oIn an(Id thil(l (ensIUses in 1954,

1h8PSp of Cr(1ie Pa1,(1 wvere 111a(e (depictinig the 1y1eas

of openi water a1(1 of surface veogetattion. -In1aIddition,

(8(1 }lplant hed( W8s (described( by species so thllat :11i

(Icliate )picture W..ts flored( of tfle vegettation withiithe pOnd(1:it the tiilie of each1 ensus. Tlhespositiono-f c(a-li turtle was superimip)osed(ol ttiese, base Iiiaps.A similzir imapwaxv,-s isimde onl June 15, 1957, anlaid 78

(ChrySc(my /s were obse Ived.

Ini extai-iiriiiii the 1111)s, it becaitie ap)p.1C1rt tflitttlie turtles wvere not (listributeCl ait iandoiminill reh l-tioin to tfie 1)ond1( surface but vere(clumlped1 ill those

areIas which had vegetation floating at the surface.

()II June 22, 1954, the ratio of the area containing

surface vegetation to the area with none was 3 :1,

while the ratio of numbers of turtles observed was8 :1; the difference is statistically significant (Table

12).

TABLE 12. Chi-square tests for habitat preferences of

Ch rysc myis.

Per CentContrastirng of Total Nurnber Number X2 P

Iate Situations Area Observed ExIpected

June Aquatic Vege-

22, tation Minlus

1954 Nuphar 75.5 63 53.6

6.81 P91 =6.63

Open Water 24.5 8 17.4

June Kanunculus 92. 7 39 54.7

22, 61.8 P99 =6.63

1954 Potamogenton

foliosus 7.3 20 4.3

Aug. hanunculus 88.4 134 127.3

13, 3.04 P95 =3, 84

1954 Filanientous

algae 11.6 10 16.7

June filansentous

15, algae 38.6 53 26

1957 45.8 P95 =6. (3

Potamogeton

folisosu 61.4 14 41

Chi-square tests were also imade to see if ChryI-

denojs were distributed at ranldolil aiiion- several (

vegetated areas colmlpose(l of different species of plants;

(Table 12). On June 22, 1954, itiore Chrylsemls were

found in beds of Potaumogeton foliosus than in ones

of IRanunculus lonyirostris than could he expected on

the basis of a randomi distribution of anillmals. How-

ever, on August 13, 1954, nO difference ecoultIhe shown

in the plroportionl of animals found in the areas of

filamlerltous algae colltrasted to those in the areas of

I(tonuneotl1otslonyirostris. No other tests eould be used

to( compare the distribution of ChryJsberros in different

are1.1s because the relmaillimig aireas were ra'ither small

irl 1 954 and did not contalitl miarly turtles. There

were sigiitificaintly imiore painted turtlesI observed in

areas of filamlenlto(us allgle thaIrl in a1reas( of PotamoyFge-

ton loliosY.s Oll Julie 15, 1957. It is so(miewhat (liffi-

cult to iaterplret the status o( filaimentous algae.

Theie is aI temndemity for the 111-11e to o(lclur isli ilower

water than (1(1 the (other plaiits. Hiowever, there' is

11(1 si-iiifilant (lifferenlce in tile (listributi(Ill (If Ch rij-

.se (l lS within beds of filaimlleltouus algae wx'hich aIre

along shore 01' in the lli(l(lle( of the poiid.

I)uring theSt1111111er (If 19.53 the surfae ( If(o CranIe

Pon1d was aI nll(sa;it (If various p)lllts and openll waIter.

TIl )lalInts reclle(l the surface ait (hiffterelt tiiles sO

thalt aii idlidictioll oIf the preference by turtles for

certa ill vege'tatio(l tyl-es coul(I be (leterllleide(l by ob-

servillng the miiovemiients (If turtles' i'itol 111(1 (lilt of

(crt'al iriol r'egionsli as new l)lanlit beds (develope(l. By

c(alipiilr'ilg- vege0tati(Il I)as with thle' distribution of



1 8) OWEN J. SEXTON E(OlOgi(alMIOngra1phsVo1 ,N(.2

STAKE 50 0

A

RC

STAKE 9

STAKE44' 0

x 0

R,6-14

B

STAK ;0~ R, C, 620

C %%6-20

C6-2014

\ - X ,tA K E,

OSTAKE17

P RE 7 - ,)- R

FIG. 7. D~istrib)ution of' eon1Petratio11s Of Cliryscwmys

ill rela-tionl to tile apmpearancee andl disappgearanee Of

ni, -ua--tie; vegetfintiol .lt the surface durinig .1953. Each

eire le reptl esenlts anl inldividual almimlal caught lby anly

metliodl e.xcept balitedl trapls. Solidl b)lack aI eas alre b)eds

of' .Xtp~ltar advt ena; area.s encllosed<- by) dasiledl files tire

o)tlier plint beds(1. II1 e~ieli nlofiition tile letter indieti;tes

Hlev pblflt loenited inl tilat arleal ns f'ollown s: C8, C/lara~; P,

Ramiancidlus longJiro~stris; P. Potanl0ogetov foliositsx; RI,

riv-ulkrine(eous (i~g,-ie. Tle nlumb~ers inl enlel. nlotation referto tile jumoiti li:md dafy n 1),,rticulnr pbluiit lbed was first, ob)-

served'( a:t tile sul-ffle of tlev wffite~r. C:omlpare wnitli Figulre

X8.

Chrysemys captured by nietting and inuddhli, it was

possible to follow the shifts in population. centers(FigS. 7, 8).

The vernal distribution of Chrysemys dluring 1953

was centered about four areas, and it is evi(lenit that

T'Iypha latifol/ia and Nuphar advena were the only

aquatic vegetation utilized by Chrysemys (Fig. 5).

About June 1, 1953, Chara appeared at the surfacein the area off stakes 50-51, and Chryseoiys quicklymoved into the bed (Figure 7, A). At the sinie timlle

the tuirtles abandoned the Naiphar which never again

was highly utilized that year except occasionally about

the periphery. The floating leaves had risen above the

water by June 19 so that the plants were emergent.

Painted turtles were not con1on. in other parts of

the pond at this timle.

New clumps of Chara., llixe(d with Ranca/luas,

broke surface off stake 44 about June 14-16, and

turtles were evident in this area about June 20 and

'21 (Figure 7, B). Chrysenmys had also nmovezdintO

an area of lianunculas which had reached the surfaceoff stakes 8-9 (exact (late unknown), and they wexre

still present in anl extension of the Chara bed near

stake 50). lowever, the Chara in the area adjoining

stakes 50-51 never again attaine(l the number of turtles

it hlad previously contained(.

Aln extensive belt of Cliara apl)eare(l at the Surface

fromt stakes 17-30 about June 20. Turtles wverefound

in this aIrea'I (Figg. 7 C) , but largely iln those pmortions

()f the (C/.ar whilch also eontailled a highI p)eleentageotf Rana nca/as. Scattered patches of /ao aii('01(s in

the aiea froni stakes 1-4 harbored soiiie turtles. 'I'Tle'

area aft Ranimcitlta and Ch(ara (Ramlnc/fas heeaiiie

the iiior-(eabund(ant) off stake 44 still containedl (Irlr-

yscmij in Somilenuiiibers.

On July 19,IPot(an oycttoanfolioos wats lat the sur-

face off stakes 11-141, and ttliles so(11 appear1Tdlill this

a1'ea (igUlre 8, I)) which had Jpreviously been devoidIof teiiti. Ainothei area o'f J* fo/iosl was at the

surlface by Julv .12par'allel to stakes . 52-5 3. Ch)'i-

s('IOI8 were ca ltght in this alrTca.

Ilie most inte(esting shift o(eurred in A ti-tst of

195a3. Thebelt of Clr(/ia iti the eastern porotion of

(8lalev P(id now exteanle(l froiti staikes 1.7-sl. (Fig. 8,

EJ) It had previously beell inhabited iln number s by

painted turtles only ill areas where Ranatm oitlit.> was(o-(lOiilillant. (,n)et species of the aalg,(alI'a olily Rivu-

lalri-aReaC (p(robably Ri ca/aria inin a (a, although

(Glocotric la niatanfls is also, found in Cr.a1ne IP1(l),

which lhad beell go'winglle' adnate to submllelged stemis

a11(1 (lebris, broke loose and floate(l to the surface.

The )revafliing westerly windls swept these Jplaiitseastwar11(lwhere they becaelle entangle(l ill the CmI(o'a,

(speeially off stakes 29-31. This aeullaulationl of the

rivlarliaceous 'algae in the Chaio beogan about Aug-ust

7. There ivas also al heavy influx of CrlSrsr ilso into

this aretla which started no later than August 14 aln(d

(eoitinue(1 until the en(l of the month. The floatillng

algae then (Iie(l,d and( the C rlyseiiils moved out of the

area..

The situationl in 195)4 wsas ver y (lifferenzlt, for



April, %159 P0PU'LATION OF TILE PAINTED TlURTIE 129

\, '4 0

\ \ ~~~~~~~~~~~~~~RI,C

C :0

/~.STAKE 8214 '0'

\-0As~liO*1

17,19 OR

I 'p SLIGHTLY EARLIER 0 %

II 100%

0ItI

D~~~~~~~~~~~~~0 00

~~~~~~~~P,7-15

FIG. 8. 1)istribution of (coliceiltr-ations of Ch ryscoins in r-elaitioll to thle ai"i(earic 111ead disappearance ofa(luatie vegetltiOIl at the surface (lurilig 1953. Each ciicle repliesclilts aii ilidividual aninial c'auight b anylie'tiO(l ex(epC t ba ite(l t-aps). Solid black areas a ie(e(lds of Aitphar (t(r1(1na0; areas eliclste )~ daslie(l lilies a ic

othert l)aint beds. InI each notation the letter iln(licates the plant located ini that area as follows: C,Cdashed alR.

Ranitt1i(t11is lo0. firoNstris; P, IPotamooioton foliosl/;; RI, r^ivulariaccous alfl/a. The numbers in eacli 1otltioli

efer to the iiilot anid lay aI pairticiular plant bed was first ohser-ved alt the surface of the water. Coiiipaiyewith Figure 7.

(01(l( {Ihfs XvS the pi)le(lo)lillinltn l1ilt of the entiie

1o)l(. HIeIlce, this Pl0(I'(lIle o(1 (0o1ill)arlsOl1 (OUl(l

not heemipl)l0Ve(l(dil

ing1954.

Chryscti(l.s 'apipp vs to hanve 8 hilei i elly of plfetlr-(lice o01 ceit'aiill 1)1h1t t 'y)es

811( eoliditiolls wNithill

rane P11(1. Tih is is the or(der oft illerensill- )itreir-

t'll(" (1l)(p waletr, floa titing N (I-(o 1(d((1co, C(hof Sp.,R-((0 i(11/15 /onl Qirostris ( 81((lie or1 with (o11r/mo sp.),

tilhimllitolls alglox, hrlXIla'iCe(' With (l/ol) Sp., 81(1

Pot(e 1lc()!to()1 f0i/osols. H0(il(('(1cof((s, filainentoliutos lI'xlgle

111( th e Ii vuIhiii8ee (115OUS8lgo8 1ip8p)t1 Ir 1 8bout equallyta vo)'(( :11(1 8lre so eollsid(11r11) hi(11. V). folioNs)) is

po ohatbly thie p ie1f'11r1( pIt iut ill this p mld, und(ier1the(Oliditiml s obs1ervd(l.

0(cr alt Ijit1ic p) lilts whlih (11Sll to be alvoi(le(l, at

It st (our 'n the aestiv Il seasons Studied are P'ot( oa-y/-to?) mli(t((s, 1'. (mp 0/li/fifs, 7p1/1)1( 1(th(/ oli, Cf'roto-

/)1l/l/lI) (/(c'/("fsl(/i/, eiieigeOtiit ' 01)h(/r and E/eocoriss). The T1/I/h1 sectioii (f the ponid is heavily popu-aIted(, but this aipea 1ils to he (lue to the nailts of lila-telietus 8l-nae extenlling out fiomii tiel p111)h(1. Pot)(-

a1loyeton /)fftim(l tis is plrohahi I8 Prlelferel dpi lit, hut

the area lovereli hv tilis speele(-s was too sii,-ill todetermine the plIee it oIluepiedl ill the hierarehy.

Ifespn)oses oIf inl/iridll) thirt/es to eget(otion (h((ayeCs.

The turtles llovino, into reeenitlv suitable area is of

Crane Pond (o111ul eonceivahlv (colife troiil two source's

nilllals whlich enli-ratedl dlulrilng the spling and have

recentlv retlurnell to the pollnd, Il alliliiis; which haveheen establishe(d iii the 1)pon(dsolmle tiiiie p)rior to theappearance of the surface vegetationl. Many of the

inva ders of new masses of aquatic veget'Ition doliit-

less areIIttnte

111 i.t tIil,,ligralits to the p)n1d(1, bIlt

it is known ti alleacpture-reea 1)tule datac1tllhat soli e(t' tile individualis wvhich licave previously heeill resi-

(lhe t iHt ar s(lll1 lwat restrlieted a1l'e will ov11 et'i Iito

liewviv d(levclh(11d regiolIs. Indeed, if' ceit'a.ill tvl)es of

l)iailits ale' p)rertlred over others hv (CV11qscoo,,s,thishellmlviOl \rXv (l hbe expected. The stiulinli lrespollsiliefor i li ti Oatiigl li'eint out of olc carleaa'c Id il[toaill (the( (a.Ill he l)ositivet' 0I, Lnceative In (lh ia (tel, 011)0tl. Thu11Is,the animal ayleative ommea.le heao'1se

thiat airte Icks a necessa lv reqluirelenet, su(h cals(l(l((h miica'cl Siloplpot, a11(1 may restrict the aletivities,to a Ilothelr arlea h-,icli supl)lies the Illissilng fteature.

A hed of Pot(imofyeton foliosifs realle(i the soil fcee

(if the wvater off sta-kes 11-14 ahout MIay 26, 195,4.All ni(midentifie( agelicv destroved this vegeta tiollaftt'tJulv 8 so that the area was open water hy Julyv .18.Fios. 9A ain(d 1(C show the successive sites of eal)-ture of' 2 Chr(/sei,, wxvhichhad beenn established inthe wvesternpt'lart of the p)on1( prior to Maay 26. InIJune hoth turtles m(oved into the '. f!olilosus and sllr-IoiIIlidillng arei(5l1. A third (Chrysem /ls (Fkio. 9,B) wasalso resident in the same area Which had l)eenl occu-pied hy P. Ioliost.s. The turtles shown in Fi. 9Iovel into the western section of the pondl after the(lestruction (of the l'. oliosius and didl not return tothe mlidlle imimit;the indhividual in Fig. 1(IC remalined

nearbh at least until the miiddle of July but thentook up residence along the shore fromii stakes 44-48.The shifts iii the honme ranges, or activity area, of



18() ()xvv:N ,J. SEXTON F.> dIIOgical.NEMoiio-,raphisVol. 29). No. 2

these aummialswere coreilted( with the fo-rmation and

(lestructioi of certaini vegetation units.

\SCALE IN M.

)@ R |TA~TKE_14

8,8t}-0 3 6-28

P,PTR R FA

9,I0-12 6,8-6

I ,4-17;2,4-2 5, 7-16

A. JUVENILE IN 4TH

SEASON

SCALE IN M.

\' 0 26

\ I tei-t5, 6 -2 1

* ' !O t4,6-9 g 14,8-21

\s --", \ /ffi~~12, 8-15

\ ~ ~~~~ 15,99-25

5/

<i~~~~~~~10,8

- 4

6, 6 2 8; 8,7-16 I,

7,7-16 a%

Z,5-16

16,10-9 3,6-6

1, 4-7

B. FEMALE IN POST-I5TH

SEASONFIG. 9. Loentions ((irclesn of two Chrysemys in

relation to aquatic vegetation during the aestival season

of 1954. Sequences are, shown hy the first numnber illthe notaition; the remniajing figures in the notation refer

to the month imld(la1,ys of aphture. The vegetation types

a11reill(licatte( by letter as follows: Chara; R, Raom.uii-

colas ion yirost'is P, 1Potalloyctonl folio.is; ll, rivul-

irianceous algae.

A slightly iliffereiit case is preseate(l in Figure

101). A strip) of Ch/wr sp. had reache(l the surfaces of

the wa-iter off stakes 29-31 before Aunoust, 1953.

About August 7, colonies of on(eAof the rivulariaccous

alolac, which had been attached to submer-e(l stems

throug-hout the 1)o01(l, floated to the surface 111(1

w ere arNied eastwa dl( )bv the wiryi. The rivulari-

('e(oUs (algae heca(imie'ent.aimgle(l ill the eXp)ose(d portions

of the (Cmra off stalkes 29-31. and formed a, fairly

fle'llse mal1t,there. This conditiomi remoaiime(l until the

endl of Agmust. By late June a painted turtle (Fig.

101) wNasalready( established in an area of Ran aun-

c-ahis and( Chara( off stake 26, but it move(l into the

region off stakes 29-31 some time in August although

nothinig, appeared to have change(d in the original

aiea. After the disappearance of the rivulariaecous

algae this imdividual moved westward away from the

former areas, going into the central section of thepon(l before returning on or before october 3 to the

eastern part. It seems noteworthy that this turtle

(lidi not movet into the region off stake 30 before the

rivulariaceous algae were present even though the

Chara wv.ais-.Irea(lxr at the surface, aioll tilat it left

the area after the rivularitaceous algae (lisappearel

altlhough the Chara was still present. It is also

interesting to note that in the latter part of Septemn-

bler it remained in and near a be(l of l'. foliosus

wIichl relachcd(the surface about August 21, but which

(lisapp)eare(l about October 4. In October it returned

to the eastern part of the pon(l.

It is easy to imagine that animals just returning-to Crane Pond encounter these v'arious areas by

chance as thev move in. Less clear is the method by

which residlent animals become aware of (lifferent

areas in Crane Pond other thanl those in which theyare locate(l. Presumably all established aninial is

soMIewhat sedlenttarv as long-- as its reqluiremnents are

1(t lv its imnimeliate environiiciit. As examples, all

the turtles in Figs. 9 and(l 10 remained in the one

areal w'ithout moving ilntO a(ljacent a reas. When

they (di(l leave, they sented to leave for good, an(l

exotlus was correlate(l with ain environimental chalge.

Iloweverl, mity (lata indicate that (iChi/scm!is somietimiesiakes extialiinital jOUrneys. 1)uring one 18S-dlay

Ierio(l in niid-suinmer, a nmale occupie(l a small areawithin the middle part of the pond, left it, movin-

eastward, an(l then returned. The shift was evi-

(lentlv not aassociated with any known vegetational

chaiige. This type of movement could( indicate that

an occupied area lacks sone essential, or at least

preferred, feature, an(l thy deficiemicy acts as a,

stimulus. The response is movement out of that

area. If a more favorable site, e.g., one containinrg

necessairy sul)port elements, is located, the turtle re-

maillns hiere. If oillv less favorable areas are en-

coillitere(l, it is conceivable that the tur tle woull ie-tullrn to thle original area or coiitinue wanlering until

a favorable ole was found. Ill the aestival periodl it

ap)p)e'ais that the structum(e of the v-egetatioii is the

featiture of tlhe habitat iiiost iiiflueitial in (letermililln

(lis~tib)ltioll

Th1e1nuinbem's of Chr ilsebnqs which slift the site

of thleir activ ities within (CrallPeII(l(Illluing the

aItstival seasoln is iiot known Imr certaiin. Since ther-e

is nlo iil1)i tial niethodl fIor judginl whether or nmot

ain alil mal's travels alre all with4ii the b)oul(ls; of a:1

single activity area, (an a rlbitr-a stanl(lr(l was used

to g(aill a Ilrouh estimiate of thle number of aninlals

wh-11ielIcestric;t tleilr activities to Ole l'fllo e thlroulglIolt

tIle aestivxll seasomi. Tlleme wN-ere22 turtles which

wi'('l capture(l 4 01r imore times (dii'-ing either the



ApI~ril.1959() ISPOPIULATIONOF TILE PAINTED fURTLE 131

SCALE INM.

0 26

5,66-29

7,7 -17

6,6 -3 0 4,6- 21

STA KE 4

9,8 -20 ~ ~iSTAKE 11

9,8200 -

8 ,723 3,5-2 3

2 ,5 -2 2 4 --s_-

1,4-14

C. MALE IN 7TH SEASON

2 ,I-1 STAKE26

1,6-273 ,8 -23

RIC ,

STAKE3I8

6,9-12

10,10 -3

C

8,9-28_ -_ \9,928 )

*P, ' \9 -

7 9 - 20

I (

'SCALE IN M. - -

0 26

D. JUVENILE IN IST

SEASONFlni. IU. Loc.utioms (circles) of two Chrysemys in

rehi tioii to 8(1mi8tic vegetuitiom durhiig the ilestival sc.isonof 1954. Seqiiences ;i re shownv by the first nuiiiber in

tlie iotfiltioll; the lei 11illilig 111111 ic rs refer to the 1iioiithnid (hiv of e.iture. The veget~ition typies are in dic.-ited

bY letter Is follows: (C, Chal; R, Ralincll iulas 10u(1i-rostris; P, IPothamoo('tol foliosus,; Ifl, r'iVulv.'in.icet'oUs

ilgo'.c.., 1t.9

1953 or the 1954 tiesti vii seuisoii. Anps sioilig the

oiiits -at xwii i each iiilivi dunil wns (eaptilledl wver

eXuilililid, (iil1 tiii siasoll's lilovelllits for each iliiii-

viiiual Were (classified n-,s follows: 1) restrictei, if theenphirtie polilts were all w-ithiii aI sing-le limoion'eIemisO

part of ( nine 1Pond; 2) exttnilil itnfi, if a sing-let

("iaIptuLeoiitsiiie ofi ,-I restriited area wa5 prei d)(((l atid

succeeele(l Iy clatures within one locale; 3) shiftillg,if the turtle had been sedentary within one area buthad later shifted the site of its aIctivities to another

locale. Using this arbitrary (hisstifitication, approxi-iatelv 20', of the aniiiials were restricted in theirmoveitients, another 2()0s, had extralimital movements,anld about 50-60%/ of the Chrisevos had shifting

Iiioveinents.During the aestival season of 1953, 68 painted

turtles were captured 2 or niore times within CraneP0o11d. The minimium direct distance between the mostdistant points of (eapture for any one turtle rangedfromii 3.5 ma to 300 iii and averaged 89.5 iii (thestan(lar(l error was 15.7 iii). Fifty Chrjse;m ys were

colltured two or iiiore times duriiig the 1954 aestivalselsorn. The niinirnumii direct distance between theliost distant 1)oimlts of capture varied froiii 6 in to2)92 im and averaged 91.2 iii (the standard error was16.7 iii).

Features common to plants ntilized by Chr.semqs.

A comaparison of features comnion to the severalspecies of plants which are preferred by Chrysemysmany reveal factors to which painted turtles respond.The llaits iiiost often selecte(l by turtles includedPotamoogeton foliosls, Ran ue11fwkul1uslon girostris, andfilanientous algae of several species. A second gfroup,so(iimewhat less )referre1 alnid consistinrg of Leersi(a

oryzolleides with Spirodela polyrhiza anid Chara sp.

with rivulariace(us algae, were conipared to this firstgroup. The plants of these two groups shared several(characteristics. A third lot of lplants consisted ofuiiused species anld species initially used but laterabandoned, such as Chara, sp., Ceratophqllum demer-stun, Nmphar a(idena and Typha latifolia. These

plhints were comiipared to the first group to establishoutstaiidiiig differences.

Other authors have suggested that the structureof the vegetatioii inhabited by animals is a featurewhich they select (Beecher 1942), and the plants inCrane Po01d were examiine(1 with this in aiind. Struc-ture in this l)aper follows the definition of Dansereau(1951) : "Structure is the organization in space ofthe individuals comiiposing a vegetation type or asso(ia-tion."

One structural feature coimmon to both used andabandoned plants is the mat of leaves or thollli

at thewater surface. Turtles avoided areas of open waterif otherwise suitable submertrged plants were ill thoseso111ie almoos, amid thev also aivoide(ld regions in whichthe 1)10mits l)oj'ecte(l beyonol the sufoie so that nosut ce III,-tfolrmied(l.

The preferred )lomits- possessed onl( e characterwIi1ch was evideiit when the beds were observed invertic-al cross-section. These )lhint iiisses could becmisiilere(l to hotveo 'F-.stiuiitiie. The horizontol barof the T -ejl)teseiits the dense iiat of terminal leavesflootimig fromii the surface downwardl for about 10 ecii,while the verticail b)ar rel)reseits the isolated stetis in

the lthlerwise Ol()ei water heiieatli the miiat. Sincethe mtllia steiis branlch out into great miass'es of leaves

(listailly, there is miuch greater milass near the surface.This arIa migeii-eiit is miioditied for tilhimmintous algae,



1 32 OWEN J. SEXTON Ecological MonographsOWEN 4. SEXTON ~~~~~~~~~Vol.29, No. 2

for most of the filaments are at the surface. Some ofof the thalli are attached to submuerged plants and

(lebris, and others are submerged in shallow water

so that a T-structure is attained here also. Actuallythis vegetation type is better compared to a table,with the top the thick mat of surface vegetation, andthe legs the rooted steims.

Another common feature of the structure of thepreferred species is the porous nature of the surfaceniat. The finely dissected leaves of IRanunculus

longirostris, the ribbon-like leaves of PotamogetonJoliosuis, and the filaments of the algae have littlein common individually, but when each species growsinl dense aggregations, the floating leaves become en-

tangled to formi a mat strong enough to supportturtles. However, this mat is composed of so manysub-units that it retains a certain lace-like quality.

Leersia ory4zoides, with Spirodela polyrhiza en-

tangled in it, forms a mnodifie(l T and is evidentlyuse(l by turtles during the vernal season. The gramni-

noid is not emergent at this time, but floats on thesurface of the water forming a thin mat composed oflinear leaves. Spirodela engages in these surfaceleaves, increasing the cover.

(7ha'ra, an abandoned lplant, has a cross sectionwhich is radically (lifferent fromt the T-structure.The strandils of the algae fill miost of the space be-tween the bottoml anld the water surface an(1 resist1m1ovellmietthrough thilel. Henlee, (hora niasses tendto he cuboi(lal an(l fairlv solidl. NAa1)har adl 'na,another al)-iii(lone( l lant, has a T-structure when theleaves float at the sullface, hut each leaf is a sing-le,in ige, cirnla m'ele aent ich contrasts stronglv with

the leaves of the pireferred )lalnts.(,., ,topllo le(}eisa11w, eigenerallyan1 aban)llen(e

)h mnt diii ing the perio(d of stu(lv, is coluana'- r1 inlshalle when growing attache(l to the substrate as it

(hwesin (Crame Pond. At tin0es( this p)lant foills imoats.

at the sntuace when the stemis are longer thanr theaiter is deep). However, the sublmlerged portion of

the pla nts is still quite colnmnar .

The h(Ohaa-rivularltiaceosalgae combination of

Augulst, 1953, is miore difficult to interl)ret. Perha-ipsthe rivuhlavia ceOUs aIlg'1ae on to1) of the Chll0 folrmisai miodie (l T-strnicture althotughI a 2-layered( unitwould appear to replresent the situation better, the

Upper layer' b)einlg cmposed(l of spheres an(l the lower

layer oft cube of dense (Ihara strands which di(d not

Ireach the suimfa-ice. There is also the distinct p)ossi-bilitv that the turtles were fee(ling0 upon the rivulalria-(eous planllts, but this waslmever observe(l.

The plants in Crane IPond(Itended to grow in purecolonies until there was a (dras,-tic change in soine en-

vironmnentll feature, generallyl water level. When-

ever'l this changii-eoccurre(ld it was followe(d by a ra-ipi(lincrease iii the nunaber of l)lailt sl)ecies foumlI in thatarea. However, the areas of I(mananelus and IPota-

anogeton Jolioslts in which Clh'irseoyJs were foundwere quite hoiogeneousu()u ntil August. From the latter

l)art of the vernal season until the ini(l(lle of the aes-tival season in 1954 the plants found withi llai area

were scadle(l for sociability oli the basis of covera-lge

(l)ansereau 1952). P. foliossus increased from 3

(small, wvell concentrated colonies; local coverage 41-

60%) in the spring of 1954 to 5 (pure colonies; local

eoverage 81-100%) in the summer with otily small

amounts of Ranunculus present. The P. folios/Is de-elinued an(l was replaced by many other species, butthe area was never again inhabited by CI/rysemils in

ally numbers. A typical Rainncultus longirostrisstan(l was scaled at 5 by late May, 1954. The IRonun-colus continued to be (lominant throughout the aestivalseason, but some filamentous algae appeared in. theareas of Ramnnculus by July 4 anrd Ceratophyl laia

demersum by August 24. The areas of Routiaacullis

continued to be inhabited by Chrysemijs all summer-.Adleantuges of the T-structure. InI plants with3 ;a T-

structure the mat of leaves floating at the surface pro-vi(les a platform over which all but the largest Chryj-

scmy/s can move. The turtles are not comipletelv out

of the water, but at least half of the shell is eXpoied.1andthe head may be easily exten(led into the air.

At the 5same time the animal is in water (lep elloughso that when the head is extend(led straig-ht forwardor (lepresse(l, it is beneath the surface. The turtlesforage in this position and food may be swallowed

easilv.

Thle pOO(US and yielding nature of the mllat per-minits easy access to the surface fromnm benieathi .ai(1

elasy egress fromii the surftace to the deeper water so

that an alar11d(1 (ir/semoys milly (live quickly throulgh

the malt anld swill awNayl1'ill thie (lealed regionll bellen.eththe maudt.

Tfen)mi//atures taken onlAugust 24, 1954, inlhieated

thlat the sum1face te'lllplc'aturc of the w\ater' ill l)lait

beds was within 10C of the' .lir teml)elaltuile. I Io w-

ever1,? the waterl just above the bottoiti wa 30Cto(

90 C cooler thanr the surfaced water. Tlis lr(''elrOVl

of emol water could provid'e a shelter (dl img lperndllsof ligh surface tlll)emeratules. Inll conltrIst, observa-

tiOmIs mitad(e()011 Septemtiber 24, 1954, iii a bel of fila -

nemito;is algaze inlllicate tlmt this wa 11111 111)1i('1 ltyeil

may also be advantaeaous. The temlll)eratll'e of tills

sutrface water w1as 18?C. That of the suirfaewewatert

6 Ill distailmt amld ill whichl there was no suit a cc ve'g-

tatiOmi iegistere(l 14.50C(. Themte was ai (/)l/n1/sC i/s

feeli ig at the tinnc ill the fila inentous miHiat. It ((mild1

easily be that the water surfacee of the IlIat nay w.arm

Ul) quickly inOughi (luring c/ooil perio(ls to permiiit

Ch/.sc//uils to feed there while nearby aireas 11/v be

too ((//. It was ind-licate(d (arlier that (/Ci/Se// *s

lrobably begins feeiling when the water temlplleratureis aboiut 150C(, so that the importance of this xZamine'r

stlatumll would inl(crlease at this critical level.

Perlhaps, imlstea(l of inlhabiting certain plant beils

because of structural advantagq,,-es, painted turtles ill-

vcadle these areas to feed upon these plants in prefer-en(ce to others. Two exeellemit studies ofi tlhe fee(ding0habits of (hrly.isciiys (Raney & Lachner 1942; I agler

1943) indicate that this animial is a very generalized

feeder. The former paper showed that volumetricallythe fto// wa1sabout evenly (livi(led between lplant an(1am/il//alsources, while the latter autlhor foun/l a slight

pieferemIce for plant mnaterial. III any of these



April. 19.59 POPULATION OF THlE PAINTE;D TURTIE 183:I

stu(lies it is difficult to separate the plant materi,al

elatexi per se frao the plant material aecidlentally in-

geste(l with animail f(1oo so that the, actual volume of

i)Iant foo0( may he slightly less than indicated. At

any rate, neither paper shows that Chrlqsemys had a,

strong predilection for any particular food, plant or

animal. Plants found in Crane Pond an(l vicinity

which were mentioned as food were various speciesof filamentous algae, Nuiphor, IPot(ilaogeton, Najas,

ASpirodela, Lemna, and Ceratophyllw1n demersiimi. In

a(ldlition I have sight record,s of Chrysemys eatingChara sp. and Ranuncubls longirostris. The wide

variety of food eaten, consisting, of plants hoth fav-

ore(l and unfavored, and many animals, seemns to

miegate the idea that Chry semnys seeks certain areas

because the plants therein are preferred as food. The

method of huinting(, to be described later, also pre-

eludes this belief.

I)istribution 'within plaint beds. It has been shown

that Chryjsemys is inclined to inhabit certain areas

more than others, so that their (listribution is clumped.It (cala also be shown that the distribution of painted

tur tles within ai society of one dominant plant species

is (clui)edl anidlnot m ldomilize(l throughout the entire

bed 'evin though the vegetation may appear honmo-

ge'net'OUS. (lark & Evans ( 19J-4) have presented a

letlho(l utilizing- dIistatice hetweeii meiarest neighbors

ais ai metaiesure of the sp)acing of indi-;d(luals in a popu-

latioll. Fdllowing this technique the (listance l)e

tweeii nearest ie-ihlbor"s within al Pea"rlsof Baa ofwlus'111?l

WaNs teaIsuure(l atied the lR values (leterminlel for their

(ist i bution on .Junei 2'2 ad(1 August 13, 11951. Clark

& Eva us state that the va:lue oft R will 1iatige frotii 0.()

foi comi)lete clumtiipti through 1.() rndoim (listri-

butioti to 2.1491 for uiiitoiti (lispersioln. The values

ohta i lled for Ohr(/seol/s ( 0.453(3 amd 0.42504() respe-tiv'elv ) ilndica1te that th1e a nlilila ls were ( il1lped within

a11eals of Rmana l(alas, a11(l the average (listance be-

tweeni iea i-est neiilihor \vas 71.(itii andil3.9 III, r-espwe-

ti v-el . Al sitilala teeliti(ile could not be c'iiiploved

fol other llaplt beds, for thlelre were iot etioughl turtles

iii them. The two R values, 0.4536 anmid0.4250, ate

not sinitficatitltv different, indicatinlg thlalt the popula-

tiI( W(Iswa5 ohal)lv respond(hing siiiiila lv- at these two(i fferenit titles.

A (lifticulty in atiV stuldy of sI)ae( illtg of wild alli-tals is that ot1i (1dme itot ktiow hlowNiiiuch ar-eaaliI

atiiall or populatioti is a(ecu)yitig. This is especiallyvtrue if th'e allil at (liestri buted thlrollulgout only

onte ))ti)t at ao iin appa etlitlv hoollogeieous allrca, asi

is the (c ase with (Ch1r/semy,.;withimi the areas of Rana'a-

co111a1sin CraIllie Pon1(1. Clark & Evxan1s (195,5) have

1)l-(t'ided a iielithod fol detttoitlintig the distributioti ofatiiiiias which is iltidependet of area. This techniqueutilizes the 1)ereenItage of' reflexive pairs of indi-

viduals, that is, the iutohbelrof palirs ea'(ch inldivi(lual

of whllch is icar1er to the othier than to ainy other

indlimhiitital. For randoImIhilvdhistributed( populations this

ert'i(tage is 62.15. The paopulatioii of turtles in thebeds at R( n1lllWis far the Jute atlid August census.

(lata had a1n3 d(1 60.5%/ reflexives, respectively.

This would seem to indicate that although Chrysemtysis clumped in areas of surface vegetation, and within

ainy one plant bed, the individual. turtles exert little

social influence upon each other. Thus, in(lividuals

ap~pear to be (listribute(l at random inI these sub-

clulilps.

Ac tiities of Chrysenqls on mats of floating reyetation.

ln(lividuals of Chrysemys were commonly observedfeeding as they inove(l over the mats of surface vege-

tation. Field observations indicated a general simi-

larity in their actioIs, aliel a (lescription of the ac-

tivities of several foraaging Chrysemys should suffice

for a general account of their behavior. A Chr lsenmlYsin the first season of growth was observed 10 :05-

1() :30 am August 21, 1954, feeling in a patch of

tilanIentous algae over sonic Raanflculus lon yirostris.The path of this aniimmalwas about 11 in in length,

ai(l it generally paralleled a I5 lii section of the shore-

line so that the path turned back on itself. Most of

the feedin- was (lone in the areas of filaimentou.s

a,4sIle, andv while the turtle appeared to eat the algaeper .se on onle occasionl, iiost of the effort was (di-

recte(l towards obtaining prey. The jueeile iiioved

over or' throlugh the upper layers of the nat with theca1ra-1p(aCe just above the sur face. The, head was ex-

tenl(led forward or sligltly (del)i'esse(l so that it was

bene'lath the water wh1lenhunting. Most of' the tillme

the jIlvelile nosedl ahout ill the Xvteoctiotni as, it iiioved

throlluh it, biting illto certainl)atcllhes. OI one o -

SionI the turtle ('aught Sontc uni(ldentified(lpre which

re(uire(l albout a iinute to (crush and swallow. Aln-

other ti iiie it dlisturbed sOIiti alinil h1 liwhc (larted off,

with thei turtle followinig for 5-1-0 (eniIbefore (ai l)tur-

ing it. A thiid ('alptuie required( 15-20 secoiI(Is ot'chiewiI-11'llgTe Oh I7/(Si/s l)asse(l a Smaull stick which

)rloje( te(l almout .-3 ('ii a hove the surfailce ot thle wa teml.

As it Passed beneath this sti(k, the turtle struck per-ftiictoII'tilv aIt it, ilissed, alI(l ('olltilliued o( . This

s(11ils to ellitolIlize the 1111hitill techili qne e'iiq)lo ed

111)01l imiost (i('caliOlI0 : exp)loratorly strikes of thle he'a1d

iiito Vcgetatioii to (disturl) potelitia1l pl-ev siificieitly

to tiake it move, theil active puisuit.

Wh|en' aI (I -/sc s8l/s1 XOII011m 1)1ev at (a lidst'iiii'e

e(very effort wais iiade to cai)ture it. A wjuviisile was

s(ell to tove raplly tov lIer the Sntrace of the ve-l-ta-

tiOII ill ii liusu('ccessful attempll)t to capjitiure aii odot-ite

rIe'stilno onl the vegetationi. Onl June '22, 1955, al lairge

ma1le paiiited(l tuirtle was o1)sel'ved beneath the surfa c e

ill a(nI aret1ca of failly opell water aS it Swa11ii tIIwai(ls

ai traiisforimaiiig Hana (0temSI)eiO floa tin OII the sur-

fitce. Th'le(frog julped(l awav when the turtle wa\is1

still 20-30 cia distant. The Ohry/S;cai/s l)e'esiste(l ill-following it iiito a patch of Iot a)mogetOan folio.,ms,

where it (attetlptetd to appioach troni hticatlth. Atte'r

two miliire atteniipts at capture the tu'tle g1ave Up the(

(hase. Onl the saiiie day a haige teiidile h rqisemaypwas obseived huntin- frogs ill aI i iilaI failshion. Theturtle was ait the sui'face (ld evi(ldeiitlv saw a siiiahi

1?. ca tesbeiana about 30 ciii ahead ofi it in s0iiii Chara

spl- The turtle swain beneath the suiface to within5-10 (cmnof' the frog, but the fiog leaped aiwax'K. The(h rlse1oy1s siirfac(ed, saw the fiog again, aiila ti'ied to



134 OWENJ. SEXTON Ecological MonographsI' 4 OWEN J. SEXTON ~~~~~~~~~~~~~~~~29, No. 2

ecatchl it in the same way. The ranid again eludedthe turtle alld disappeared.

The following is another fairly typical example

of fee(ling activities of Chrysemyqs that also describes

the hehavior of l)ainted turtles when they come toulldesirable areas. This turtle, a juvenile in the thirdseason of growth, was observed from 11:20 amauntil

12) noon onI August 9, 1954. The animal was origi-allv feeding in Rananclus, moving at, or just be-

neath, the surface with the carapace partly exposedat tinies and covere(l at others. Its head remained

beneath the water except when the animal breathedor watched inte. Movement through the vegetationwas fairly steady but interspersed with frequent shortrests, a minute being the longest time taken. At times

the juvenile appeared to eat only the Ranunculus,especially ol0(, brownish pieces. Even when feedingon this the turtle continue(d to move about. At other

tiimmesit seemlmedto be searching for, and biting at,unidlentified prey with rapid thrusts of the head.

Initially the turtle was located in a bed of Ranunculuslongirostris, but it soon entered aii area of open water,a space 1 ill inl dianleter. The Chrysemys swamn

through1 this area quickly, returning to the Ranian-('8105. It continued moving through the Ranuncitlusumitil it caine to the margin of a Nuphar bed. Theturtle starte(1 to enter the Nuphar but then returned

abruptly to the Ranancalas. Finally the aninmalcaimmeto the open water at the edge of the Ranunculus,then it turned back into the Ranunealus, in spite ofthe fact that I was now in front of the animal. The

juvenile continued in may direction, moving throughthe Ranaitnculas until it becaiie wary and entered

soimmenearbv Naphar. During the entire period ofobservation tlme anmial. seeimmedto avoid areas which-re less favored by Chrqsemqs, i.e., open water andand(1Nuiphar.

Oin other occasions it was observed that a Chry-

senJ.S, mnovinig across open water fromn one patch of

vegetation to another, generally would swim well be-neath the surface of thmeopen water and frequentlyjust above the submnerged vegetation. If the dis-

tance across these areas of open water was not toorealt, the annimmal(lid not coimmeup until it attained

surface vegetatiomi. Chrlsemnys were also seen swilim-maimingjust beneath the mnatof surface vegetation. At

times they would remain there after they had become

alarmed.

Return of ClhrqsewJs to activitq areas of formeru/eaNs. It has been shown that somtieChrijsemqs movefrom one area to another during the aestival seasonof any one yea m and that other turtles will reimmain

within relatively restricted areas for the entire season.

There is also somlleevidlence that so58e turtles will re-

imlain withlill, or will return to, the stame general. area

iin successive aestixvl. seasons but that other Chrqlsemqswill not itlimabit timesammegenmeral area in two succes-siv e sulmlimiems. The extent of this voluntary return

to aireas formmierly oecul)ie(h was deterimminmedOil the

hasis of tile mabl)l)ed aestival (cal)ture points of 33

O1hrysemys collecte(d during the suimmmnersof 1953 and

1954.

It was arbitrarily decided that for each animal theactivity ar-ea of one of the two seasons mtiustbe repre-sented by at least two captures while the area of theother season must be indicated by one or iuiore cap-tures. In those instances in which the animal wascaught umore than twice, the activity area was repre-sented by a closed figure made by drawing a con-

tinuous line tlhrough the fewest number of points sothat all of the capture points were on the line or with-in the closed figure. Where only two capture pointswere recor ded, the area was represented by a circlewhose (liamueter was the distance between the two

points and whose center was the midpoint betweenthemum. Single points of capture remained as such.If, for an individual turtle, any portion of one boundfigure intercepted the figure representing the areaoccul)ied during the other summer, or if a boundfigure contained the single point of capture of theother season, the two activity areas were consideredto be coincident.

O(n the basis of the above criteria, 43% of theturtles returned, at least for a short period, to thesam1neactivity area occupied ini 1953. The remuiaining57%) did not return to the same area occupied theprece(linlg year. Actually, only 13%f of the animnalsrestricted their aestival activities to inore-or-less thesammiearea during the two summummuers.

THE AUTUMNAL SEASON

The autummunalseason, extending froami September1 until the formumationof the permianienit ice cover, isone of thermal extremes. During 1953 the airtemmuperaturevaried frommia maximum of 33?C to aminimiimummof -10?C. The air temperature droppedbelow ()C before Septemmuber15, 195:3, aln(l themi flu,-tuate(l considerably. It reached a second maximiiumi)of 29?C before it dlropped to -10?C at th, en(d of

Novemumber. The water temperature ranged fromii ahigh of 27?C to a low of 0?C durillg the fall of 1953.The permanent ice cover formned on December 13,1953 and on December 1, 1954. Somie painted turtleswere active until December 6, 1953 and Novemuber20, 1954.

Somite of the activities of the turtles during thefirst immonthof the fall differ fromii those of the remiiainl-ing part of tlme autumnal season. I)uring mumostof

Septeamber the animiials continue to eat, but they (lonot (lo so later iii the autumnal season. On Septellm-ber 20, 19.53 a Chrysernys was observe(l feeding in a

l)atchmof filamnientous algae. Thmewater temiiperaturewas 2 )'C. Oii the saimiie(lay anotlher 1)aimted turtle

capturedll(l lm(partly (levoured a Rane (atesbeimln 5.3(lii in simout-venit length. The latest date on which a

Chrlusemilsiwxas observed huntin- for food was on

Septemiiber '24, 1954 when two turtles were acetmve ina bed of aq(jualticvegetation. The temperature of thesul'face water was 18C while thlart of tlmewtter be-neathi the malt was 13?C. The insulation of the upperstratumumof water fromii tlme lower,

colder one, by thevegoetation iumatprovi(les a volumite of water whieh camiJtc warmmme(lsufficiently (luring the (dayi to enable

(?hrysC1111Js to feed until late in the season. Since



April, 1959 POPULATION OF THE PAINTED TURTLE 135

C(hrysemys feeds lethargically at temperatures of15'C and below, the presence of a warm upperstratum of water is undoubtedly an additional factorin influencing the animals to move into or to remainwithin areas of surface vegetation.

Although the painted turtles continue to eat dur-ing the first three or four weeks of September, they

cease growing by late August.The spatial distribution and movements of the

painted turtles during the autumnal season differ ac-

cording to the height of the water levels of the variousbodies of water durinog the fall. During a dryautumnal season the turtles concentrate in CranePond; during a wet season those animiials which haveimmnigrate(l into Crane Pon01 will emigrate out to thesurrounding swanips and marshes.

During,+ 1953 only 26.1 in of precipitation wererecorded at the George Reserve weather station forthe entire year. Neither Southwest Swamp nor Fish-hook Marsh retained standing water during that fall

although the substrate remained moist in areas. Theonly active Ch'rysenqos observed were in Crane Pond.The behavior of the animals within Crane Pond wasstill strongly influenced by the location of certaiuplants, but the effects of the wind blowing over thewater caine to play an increasingly important rolein influencing the distribution of the turtles. Theeffect of the wind and of the concomiitant tempera-ture changes was demiionstrated on September 27,1954, when the distribution of the turtles visible intwo areas of the eastern part of Crane Pond wascorrelated with variations in certain environmentalfactors (Table 13). Light, water temperature on the

TABLE13. Grouping Of Chrysemys in two contiguousireas with cerftain comitrastimigenvironmental features.

East end of (CranmePo0d(1o01 Septeamber 27, 1954.

Variants Sector A Sector B

Percentage of Total Area........... 44.7 55.3

Number of Chrysemys.............. 45 5

Wind Velocity in Ft/Min........... 130 430

Light in Foot Candles.............. 6000 6000

Temperature of Surface Water inRanunculus in 'C ........ ....... 22.0 17.0

Temperature of Water 30 cm belowSurface in Ranunculus in C ..... 14.4 14.4

bottom beneath the niats of vegetation, relativeaRmounts of open water annd areas containing Ranun-(ulus were similar in the two areas. Area A waswell protected frommthe westerly wind by a peninsulawhich projected out into the water at stake 38 (Fig.2), but area B was subject to the full force (of thewind. The wind velocities of the two areas were 130ft/main, and 430 ft/min, respectively. The tempera-ture of the surface water was higher in area A thanin area B, 22TC to 170C, for the strong winds over B

probably mixed the warm upper water with thedeeper, cooler water. The portion of B which wasleast inhabited by Chrysemys at the time of this sur-vey was the site of a dense concentration of Chry-semris during the aestival season. This was also thearea most exposed to the wind on September 27.Thus, the preference for A, or the avoidance of B,

is correlated with the relative exposure of these twoareas to the westerly winds and to the difference inthe temperature of the surface water.

The distances moved by the animals during theautumnal season of 1953 were greater than the dis-tances nioved during the aestival season. The iainimumdistance between the points of capture most distantfroni each other varied from 0 to 336 ineand averaged130 in for the 54 Chrysemys captured 2 or more timesduring the autumnal season. Since many turtles emii-grated during the fall of 1954, comparable estimatesof the extent of movements were not obtained for thatyear.

Field observations indicated a general movementby Chrysemys resident in Crane Pond from regionsof shallow water into regions of deeper water as theweather becamnecool, and animals were relatively moreabundant in the eastern deeper part of the pondduring the fall, prevernal and early vernal seasonsthan in the middle and western sections. Evidently,for hibernation, painted turtles move into areas whichare mtiorestable thermally. As a check upon thesefield observations the pond was subdivided into 3units, and the positions of successive captures of indi-vidual turtles were followed to see if there was anydirectional trend in movement from the aestival tothe autumnal season (Table 14). The 3 subunits con-sisted of the eastern, middle and western parts of thepond as defined by the nmajornatural constrictionsof the perimaeter.

TABLE 14. Changes inl location of Ch rysecisys within

(Cratise Po01(1 fromn the aestival season to the fall. Thesubi-ponisis refer to the natural sectiosis of the pond which

are formed bsy the indtlenitations of the shoreline (Fig. 1).

Position of Chrysemysin the fall relativeto that in the aestival season

Percentage Percentage Percentage

Location in aestival Number of showing no moving movingseason individuals change westward eastward

1953

East sub-pond......... 19 73.7 26.3 ....

Middle sub-pond ...... 14 35.7 28.6 35.7

West sub-pond ........ 32 28.1 .... 71.9

1954

East sub-pond......... 7 100.0 0.0 ....

Middle sub-pond ...... 8 38.0 50.0 12.0

Westsub-pond ........ 9 77.8 .... 22.2

I)uring the fall of 1953 the amaxinsumodepths inthe eastern, mid(ldle,an1( western units were 24 inI

(61.0 cm),12

in (30.5 ciii), and 18 in (45.7 cIii),respectively. However, most of the eastern section

variedl from 12-24 in, the Ilid(ldefromti6-12 in, amidthewestern from 6-18 in.



136 OWEN J. SEXTON' E(ologi(alMonlographls

About three-(lllarters of the ainimals caught iln the

easternil unit durilng the aestival season of 1953 re-

iiiainil ill the same aiea (lulirng the fall. One third

of tile turtles eal)tulled in the mid(lle section relmaille

ther-e, but the other two thirds whi-ch lnove~d out were

al( Ut eqJuallv divi(le(1 between those alloving eastward

al4)d( tilose 11MVilig,westward. In the fall there was a

very striking shift (721',) eastwar(l of those (Crq-se k!/s which hadfo( toi ivly been (apture(l in the

weC Sten'il p)i rt of thle p)(id.Preeil)itatiOhi Wa15 iiiuch greater (luring 1954, amil

('Onis(neiUtyl the water level was higher. This

scemei(l to sfith)ilize tilhe (itilt)ution of those turtles

which (li1 hlot eiiiigrate in the fall. There was no

lliovellileit out of tile eastern uiiit, laiid only reduced

iovNte'Ient out of the western section iii the fall of

1954. Ilowev-er, thle turtles from the idldlle unit left

that -ai niost, going westwardl. Thle (lelptl of all units

ill tle poiid was about 1Xin greater than that of the

peievous faell. A iiiiiials winch elaiigrltel thlrough the

illet duruiglt that -;(vEsasoiin 19-54 are not iuieluded ill

TIal}e 14.

Ili 1954, 40.8 ii out preeipitatioil Were( recor(dd at

the Gerorge Reserve weather station, ald, whilet the.'re

was no flow ol xvater 1)etweehI Crane Po1d(l and the

Suloll Ol0llillo bodihis of walter1' (lurilig the atestival

Sea-soi, tllheS(elattelr areas (lidl cotitatflin1sonic water

thiroutgohout tile suiiuiiicr. Rainfall, totali.ig 8.5 in,

flooded aIll of the balsilns (Uling Oc(.tober, aldl water

b)gt'o i1 to flow ilito (raiie PoIId ftroiii the west. This

influx of' wa tei was followed by, an1 emiiigationI of

( rlqsco'' s ( Table 15).

T'1i.LIK,15. The iiiiilumersof Clhry1siys emigratingtli rough tlhe ilet to (fllne POIl(1 daring the aUtumn1lllof

I954.

Number NumberDate Emigrating Date Emigrating

October November3 ....... 1 7 ...... 49 ........ 4 10...... 1

10 ....... 1 11 ...... 311 ....... 9 13 ...... 112 ....... 63 17 ...... 213 ....... 31 18 ...... 2

14 ....... 16 19)....... 1119 ....... 122 ....... 623 ........ i24 7.......25 ....... 2

The auttuiiinal ciiiigatioii is vexry similar to the

v-enuial ones. The p)eak in tile number of aninials

emigIrating is rapi(ldv reached in both eases (Tables

4 amind15), an(ld miost of thle animals exit via the inlet

(Table 3 ). The p)creenltae omiil)ositioni of thie (lifter-

calt (lasses of turtles seems to be sinilar to the (0o11-

positionof the

animiials emoigratinigduring the

springof 1954 and 1955 when substamitial numbers of enmii-

grantits were capture(l. l)uring the fall app)roximnately19.91> of the emiiiramits thtrough the inlet were juve-

Iiles, 30.1% were subadult females, 24.4% were adult

females and 25.6% were adult males (Table 5). Thesex ratio amongc all the sexually mature autumnal emi-

(,-rants was 0.85 Y Y / 1.0 S. This ratio is somllwhat

lower thaln that observed (luring the vernal emigra-

tions, 1.) Y Y /1.0 J iln 19554 aill(l ill 1915.5, lut it is

higher than the ratio observed for .adult animmals in

the entire f)opulation. This latter ratio is 0.76 Y Y /1.0 S. One (liffterience between the emiiigrating turtles

of the vernlal and autuimnal seasons is that the juve-lliles emaigrate relatively earci-ly ill the fall as contrasted

to their time of emigration ill thel spri-ng (Table 6).ITe (liel pattern of Illovellient throutgh the inlet

wxxasgeiierally tile saiie (lurilig thle two sca:isols. Ilnthe fall (Table 8) tilhe grteatest rate of emitiigatioMnoc-

urred(l about 110011 alndl shlortly thferefafter. lhe teiii-

petmature of the water flowing1 through1 tilhe inlet wxIas

lOore' varailale thain the temiperattre of water at sta-

tion's withill (CrameP11l(1, just as imi the vernal Season.

lII a(ldltioll, therle was little muioveaent out of Crane

P.011(1 (11 those (la's whllen the illet templ)ertatture (li(l

iot exceed that of thle pond.Ilie sarfac e vegetatiolon within CranmePond becat-me

i11u1(ldate(l with the infflux of wa(iter into tile pond~iduriing thle Ifll of 1_954. Taliking the (lepthl of xwterin (irame Pond o(n August 2'3 ais aii arh-itramy stalnd-

81(1( withI ai xvalue of 0 ciii, tile in(crea11iseill (lepthl can

he foll(owed thiough the course of the ('emligra.tioll.

On October 8 the depth of the watterl 1lld( incre'a1sed to

-3.5 cmii. OnI October .1.0 it was 8.('Ill. Fllligration

startell ill full onl (.)ctober 1.1. By October 15 the

(leultll () it \ltliff lE1'1t( O'(.- 1'11,(1l itdem of the xv-ater' Ilad illrelased to 20 .13ciiialo,relllaimle(l at tlitat level until Mla, .1.955. Tl'lis imlerease

ill tlle (leptl of thle wa't( 1 in (CIlll( P0o11( covered(l aa-ny

Ot thle b(lS of su-fla(ce vee(Y(tItitoll so) that thle Illat Il()

lon-er' floatted O11 tOpJ Of tlle, XXlt( 1. I ll ad(itioll, the

lhetlv rails 11151) l)eat tll(t ('t -1t1itll (tI IX'ol. Tlhe end

i'esult XX'11sthllxt the sui f(ac (If the fpo)ll(l, Wili c' it stillconblltaille(l so)1111. siirfa tce v\({ttlilIl ap)l)t'cil1r(ld s(IIlX'Wllat

like (C'ane Pon(d (lurill, tilhe spiln before the 1a181ts

attaield the surface in late May.

The autuninal emlligratioIn indicattes that thle p)hle-nomuenon of emoigration is miot limited temIllpoIrally to

the spring 11l1(1that, if the )1'roper (comistellation of

factors are present, it mllayoccur at any tiue. TImeautumllnal emigration also

su--ests rather stronglythlat the exodus is not under the influence of somesealsllnal factor, such as inc'reasing length of (laylight,which is Illediate(l through the endocrine system.

DISCUSSIOMN

The distances llmoved by Cllrysenlys dumimig any

seasoIln seem to follow certaimi )atterIls (Table 16).The average (listance traversed (luring the prevernalseasomi is relatively constammt,41 in for 5 turtles in1953 anld 45 almfor 7 turtles in 1954. Admittedly,the samples are small, but they tend to bare out thegeneral observations in the field. There is also littlevam'iation in distance traversed during the aestivalseason. The average distance between farthest pointsof ctapture of imidividual turtles was 89.5 Ili for 68

turtles in 1953, 91-2i mnfor 50 animals iii 1954, and



April. 1959 POPULATION OF THE.PAINTED TURTLE 137

TABLE 16. The extent of the spatial niovenients of the paiiited turtles, Chrgysenys picta mnarginala, caught two or

more tities duriiig any one of the aniinual seasoiis. The (listallces refer to the ninimum dlirect distance over water

Iietweeii the two inost (listaInt points of capture for each iiidividual aiiinial.

Average Average timeNumber of Range of minimum between first

animals minlimum distance Standard Length. of and last captureSeason and year captured distance in m in n error in r season in davs in days Comments

Prevernal 1954. 5 3.4-124 41 .... 21 days + 12.4 Data collected before16 days with emigrationice cover

Prevernal 19555.... 9. 2-92. 3 45 ... 20) 1.4 Data collected beforeeniigration

Vernal 193539....... ( ).0-301 144 ... . 46 13.1 Data collected afteremigration

Vernial 1954....... 8 1.0-279 63 .... 46 2.5 Data collected afteremigration

Aestival 1953. 68 3.5-300 89. 5 15.7 92 28.5Aestival 1954...... 50 6. 0-292 91.2 16.7 92 30.3Aestival 1957..7 6 -276 85.8 . ... 92 32. 1Autumnal 1953 .. . 54 () -336 130.0) 21.8 1)4 29.7 No emigrationAutumnal 1954 .... 1 11 -306 88.1 ... . 92 15.9 Emigration

1S .5 fo 7 (7/C'rI/s/i/i Is ill 195i. TIie /1//ta 0foi1 tuevel'/a:ll 11 I/ tautlIll-SIei/50/ alsCire I/Olle V/Iiaxl)Ie. III

the velii1i l seas/lll of 193h, 9 (h r/se/i/s tlavelsed an

aveV/ae (/istal/e/ o .144if whlile iIi 1954, 8 traveledia ii avciCtia of 63 lin. Tef lil/mitedl samIples all/I the

litt'l'ellee ill theaverag"'".e lellgth's of tille betweenll first

ali last (1n)tlllues, 1 3.1 (days and 2.1 da) s amakes it

(liffieullt to illtelp)let ti/c (liscrel ic11(v ill (listallice. Asil jIilal disc lCptnlleypreva' ii ill tie falIl. F1iftv-fOUr

(Chl//sel 1/love/i 1111aVer/ge of 1:30(ill dui'iig the

nuti/llumi/il sec/soil of 1953, hut 10 Illove/i only 88.1 ill

hlullilng tie sal/e pemodl in 19'54. The fact ti/at /I/Il/V

(Il/i/s 0I/S m/1//Irat fe/i ini thle fll of 1954 aln/d I/ot il

195:3 uillnohuhte(div aecounts fioI ti/c (disclrep'll(/y in

a V(1'al'x (list/Iiilce all/i tillie o})serwedi for tile tWl ye''ars.

(Wt c/ l's(, there is molet Valiati/ll ill various ell-

Xl11oll/I///l.t/Ii taI'ct/s (luring these latter tw/o se/asosll

than1/ill the preverna I al/d aesti val1 seasolls. For il/-

stIll le(, IllInilig ti/e pr)lexv/11al selIso/ls there I're inever

/11V ili//lts //t the surface, aln/i the/lre //re / IIW/lw soe

p)reselt /lul'ing the //estival. I-i contrast, X/lll/' ph)l/Uts

ll/ lisc to the surf/ace (luring tue late velrnll s5e1son0

(/s ill 19 )4) /1/ /llay (lisappear (lululig tile1 f/ll r11s

(1/s ill 1954) InI addition, the w/ater level rl/(l/illS

inlgIl (illling the plevesrlal seasonl/, is colnstantly (Irop-

pinlg dlurilng thie summ1//I/er, but fluetuates (llrin/g the

S l il/ / 111/ f /laI.

Alti/ou-h the p)aintedl turtles inhabitil/g Crane

Ponlll l/Iove' f1o/1/ onIe/ area to al/oti/er hetween seas/sIll

/11 Witi/ill a sil/gle sCe/a/1 sO l le l)tpuiati(olns of Chr/f-

,sCln//s observedl for various lelngthis of till/e by other

WOllke/ls /Ippe//r to he imlore se/leldt/lry. Pe/Irse (1923)stu/lie/i ti/e (C/ sc f/in/ys inhahitilng /i1/arlea of 547 acres

I/(/te// hehinId//i1 s/llld h/lMill /1 bhay (f Lake Aleldota,

Wiscollsil/. The turtles were n/ette/l, il/dili/(luallv

i/laIke/i /11//d rele/asedl. ()ine huln(lred sixtv-six turtles

wel e le//I l)tured/ /lurilng thie c(Iouse of the il1Vestigl -

tiO/l l)btw/ele 1917 alld 1921, al//i of these 30('ic/ had/

o/vedl /Iwav frol/I thie ilnitial poilnt of capllture /1n1d

70' /I/ia l/ot. Pe/ll'ses c/licludedl ti/at ". . . paintedttlletis /11'r /Iti/er seledI/tarv anIil/I/is, and, if their en-

Viioiiiielliit lreiaiiis ifavora)le, will remiiaini ii on)ie Jo-

allitv bmr \t'eais." Lake eIil(lota is probably al much

more staible hiabitabtthimi Crane Pond.

Cagle (1944) eOnelud(1I on the basis of homillng

eXp)eriimtents aid(l by following the iiiovements of

mIiiaike (I C /lsenos; in 1I.lliiios a111(d i elilglan that

im.liiited turtle(s (a-s Well as( other species) inliabit a

1). Irtieula r area to whieh they wNill lreturn it released

elsexx-liei-e. Th1 data fior tlis eoiielusioii eoneernnigi

(Ch5rsemoqs aire rather ,sketehy siiiee thler e w-elre few

ara(su Sitable for. Chrilseos8 inI the vicillitv. (agleI

i ec ignizeel that the return of the painted(l tuiitles to

thlese aiea Is 810ld1(1 n(ot lbe caiistrued as nil(tlial'ified

evi(lenee for homlliang. Ie also found that somiie speeies

o)f turtles inlclu(linig C(5ysemyos maike seasoiial liiove-

ients aiXwayftromi the hoille rang1e,0sduring each spring

ailot lbte fall.

(ahln (19,37) mentioned observing Ch)r !'mscoy pictl

ioor(]inoto in Illinois on1laii(l (luring the summer and

fall aind stated that their miiovemients had 1o(0connee-

tion with age', sex, breeding, Or hibernation.

Williams (1952) observed the movenments of

)aiinted(l turtles at Fish Lake in southeastern Ali(higani,

and his data show that so501 p)inIte(l turtles return

to their hoiiie range after reimioval from it. However,

WTilliamiiis nleglects to iiiention that imiost of the a reais

in which he eollecte(l were the best turtle habitats in

the lake. The present author is aware of this faet

beeause lie eolleete(l tulrtles at Fish Lake ()11 several

occasions himself. It is not surprising that the Chrq-

senmJs returnle(l to those areas. Williams found that

other Chrqlseaijs wail(lered about the lake and had no

alpliarenlt hom)1e raiig(.

The overall conclusion to be drawn fromi the work

of these four investigators who studied Chrypsemys)itoo 'argotiato is that indlividuals of this subspecies

may or miay not restrict their activities to limited

areas.

It is now essential to provide an integrate(l view

of the factors (leternmining the spatial an(d temporal

distrlibution of the painted turtle as represeiited by



Ecological Monoographs138 OWEN J. SEXTONVo.2.N.

the Crane Pond population. The importance of cer-tain factors, such as the need for water for a semi-aquatic organismn,will not assume large proportion inthe following scheme. This is not because such fac-

tors are trivial, but because they are so essential tothe physiology of the ariiiials that it is understoodautomatically that they figure large in determining

the distribution of painted turtles. The following dis-cussion assumes that sufficient water is present to

support a population of Chrysemys.

The factors most constantly associated with shiftsin location by Chr!,semxs is the presence or absence ofvegetation or other structures which can support theanimals in the water. The spring emigration occursbefore the plants have attained the surface in CranePond, and the fall eiiigiration occurs only whenautumn rains raise the water level to such a degreeas to inundate the miats of vegetation. During the

aestival season the turtles in Crane Pond are prac-

tically confined to those Ureas occupied by certain

species of plants. Typically these plants are thosewhich have a thick mat of vegetation floating at thesurface with stemnsrising from the substrate to themat. Shifts in activity areas of Chrysentys can be

correlated with the disappearance of some plant bedsor the appearance of others. All in all, it may beconcluded that the structure of the plant beds, theirorganization in space, is of overwhelming importancein determining the distribution of Chrysemtys. The

possible role of vegetation will be discussed shortly.

It is first necessary to stress that factors otherthan vegetation can and do influence the behavior ofChrysemys. Amiong these factors are currents, suchas that flowino into Crane Pond through the inlet,and the temperature gradients of such currents.Other investigators suggest that the behavior andmovements of turtles in general are influenced byother factors. Parker (1922) found that youngloggerhead turtles ( Carettt (pretta) inoved towar(dsan open horizon and away from interrupted ones.

Since Chrysernys can distinguish between lines which

differ as little as 1 mmiiin width (Casteel 1911), itis certainly conceivable that the painted turtles canorient themselves in relation to the hills north and

south of Crane Pond afl(1 to the lower points to theeast and west. Noble & Br'aslovskv (1935) showedthat hatchling Chrysemnys picta and Chelqldra serpen-

tina can detect light reflected from water surfaceseven if they cannot see the water. Terrapene carolinacan orient by using the sun (Gould 1957).

It is possible that past experience is important in

influencing the behavior of Chrysemyl. Casteel(1911) and Tinklepaugh (1932) demonstrated learn-ing in Chrysemijs, and the experience of emigratingor of shiftino activity ranges could modify activitiesin successive periods.

Although the factors affecting the shifts in loca-

tion of Chrljsemys have heen tentatively identifiedl, it

is essential to present a conceptualization of the in-teraction of such extrinsic factors with intrinsic ones

as a basis for explaining the movements of the paintedturtles in the Crane Pond area. The overall behav-

ioral pattern is composed of appetitive and consuninia-tory acts (Tinbergen 1951).

Turtles, as secondarily semni-aquaticaiiiima_-ls,needphysical support to remain at the water surface. Thissupport is offered by the water and by aquatic plants(or partially submerged rocks, stumps, etc.), or by acombination of the two. It is clear from the evidence

provided in this paper that turtles will concentrate inareas having surface vegetation. Here they canlcrawl about at the surface of the floating niats. Theycan obtain air easily, yet are in water so that they(an swallow their food. Turtles oIntop of thie suurfacemat are exposed to the sun, and the insolation of thewater surface by the mat fromi the cold wateri pro-

vides an area thermally favorable for eating in cool

weather. Contrariwise, the cooler depths beneath themat can serve as refugia during torrid weather.

The behavior of a Chrysernys supporte(d by these

mats of surface vegetation differs considerably fromtone in water containing no surface vegetation. The

supported turtles move over the mat surface half sub-merged, half emerged, snapping at and into various

clumps of vegetation as they feed. Air is readilyavailable for breathing, and the animial is in the water

it needs to swallow its food. Some turtles remainrelatively motionless, evidently sunning in the shai-low water. In contrast, Chrysemys in deep openwater rarely swim at the surface but dive down andswinmjust above the substrate or above the submergedvegetation. They generally move directly to areasof surface vegetation.

This difference in behavior suggests that thie (0o11-

plete lack of support by plants or the wron- tvpe of

support plants induces a formi of appetitive behavior

in which the animal moves from place to plhcmeuntil

presefnte(l with a stimulus which rele.lses (oeisum-matory act or acts, generally those alluded to above.

The nature of consummatory a ivl app)etitive acts

have been discussed by Tinbergen (1951). This stimu-

lus is of a general nature in contrast to the specific re-

leasers identified in consuimmatorv acts of a social

nature. The T-structure mats of Plaints, or P)altlysubmerged logs, would be examples of such generalizeJ

releasers. Such imats of mearly plant species, I? utnl-

ciulus longirostris, Potamogeton folilosus, filanllentolus

algae, all induced the (onsuLnhllatorv acts, and theturtles in such plant beds would reniain withinyi're-

striete(d areas until the character of the area (heln-ed.

As is well known, field studies of miiostvertebrates,especially those dealing with birds and nmainmiiaRls,in-

dicate that the young animals have a girea-ltertenf(-

enevy to wander than do mature adults. That the

opposite is true in painted turtles is evident froni theobservations of Williams (1952) and from the p)resenltstudy. Williams found in his homing studies of the

painted turtle that the larger turtles did not returnto the site of their original capture as readily as didthe smaller ones. It was observed in the Crane Pondstudv that there was a

greatertendency for the adults

to emigrate than for the young aninials to do so. This

odd exception can be explained oIn the basis of the

present interpretation of Chryseriiqs behavior by as-



April, 1959 POPULATION OF THE PAINTEI) TU RTLE 189

suiling that the heavier aniiiials need structural sup-

port iiiore than do the lighter ones and that thethreshhold at which the consuimiiatory behavioral pat-teiii of traveliiig is elicited is lower in the largeaaillamals than in the small ones.

D)uiing the eiiiogrations of the vernal and autuiiinal.seasons this varliablel, al)p)etitive, sea1rching, pattern is

Se(on(larilv infilueined by other factors-thermal0i1r(heiints, water (cUrrenslts, an1n topograph)ly to name a

few. The overall result is that a ninalds' niovemiients

alre oriented iather thlaii random.The final conclusion is that the stability of the

activityv llrange of plainted turtles is (lepenldent upon awide va rietv of faetors. Under the relatively un-stable coniditionis of Crane P'ond, the turtles frequent-lv shift the locatiomi of their activities, and while

their travels are all confined to the area from South-west Swallip to the easterii end of the 1)it*h, it isiiil)nossible to saw that this tsentire ar11lea (constitutesthe activityvtviaage, of a single aniiiial. U'n(ler more

stable eoniditioIis, as is presuimiied to be the case in.Peaie'.1st, studlv, thmeactivitv ranges of the animiials arerestrictedl to very limiteil areas.

1. A Iopulatioi of' apl)i)nximiatelvly1()0 indhivi(lualsof the painted turtle (Ch'risemils picta moaryinot Agas-

Siw watis studlie(l iln anmdaroumi(l Crane Pond on theE~dwin S. (George Rleserve near Pinckney, Michiganll.

2. Turtles were cal)ture(l by various iaethods. Thefollowing, (lata Were recor(d(l: i(lntification number,seX, (late, tinie, location. The turtles were released at

the poi at of cap turc as soon as possible.

:3. The aminimalactivitv eycle of Chrqseuol. was (Ie-Scbibd(l omi the basis of seasotial (litfeeies in be-ha viol. The followingI wIerletme Seasons studied: pie-velrnal~ venia1'11,aestival, and autuiinllal.

4. The preverma season, Mabich 15 to Ma1c1clh,25,w1as the period' durinig wxhich ChsIna/s1,11/.s ca(1Inet<out ofhliehriiatioii. There wais little activity ait this tilie.

5. TlIm'vermiaI saisomi, extendiling fromI AL-rch 26tMa :31, is tIme })peliod ill Which (h llr(/s( (/5 (liii-

gra-<ltes from CranmelPOmi(to outlyinig bodies of water.Tme miiigra:ti)mi OCCis oiilv(dlirimgl periods of highl

ater, III)ost of thmea'n<limalls leatvilng, the pond throughtie ildet. ()llte () the im-till factors orienlting em10iimCgr-tion through thIe inlet a1ppea'ms to be the teliipera' turereimni01t'elof the inlet. More aldults e'niigr-ate aIlld mlIore

jilxeniles reimtin inI thmepond tlraa would be expectedOni the ba-tsisof malmice. There is a1teidenen for morea (lilIt teaitles to (emiiiirate thliai imldes. Turtles WhichT'cIIIairid(in (I i ii1e P)ond (lurilig the vernil ' lseason

beca;iiie (olicenitra ted a1bout the four av-ailhble sunnings)ots.

6. The aestix <1 sea soieXtends(l fromii Jumme 1 toAu-igst :31. I)urinmithis seasoni the vernal emlimigriantsra(~lualiv filter hack iiito (mImine Pond and become

(-olicentra1tc(l iII areas in which the vegetation reaches,hmt (oes iot p)roJct, beyond the surlafce. The pre-ferred v-egetation has at structure in the fori of a

T with thick imats of leaves or thalli representiag thehorizontal bar. The plants with this structure are:I'otamogeton foliosus, Ranunculus longirostris, andvarious species of filamentous allgae. The turtlesmove about as such types appear or disappear. Itwas shown that the distribution of Chrysemiys wasclumped even within a bed of one particular plant

speeies. The activity area of individual lpaintedturtles was not restricted to one locale. During anyone season, Chrysemys may or may not return toareas inhabited during similar seasons of previousyears.

7. The autumnal season extends from September1 until Decemnber 1. It is not as well characterizedas the other seasons. The animals tend to move intoareas of (leeper water. Emigration may also occurat this sealsoi un(der the proper conditions.

S. Other authors have concluded that Cbiy'i>lscmIysis rather sedentary. The fluid nature of the move-ments of

the turtles in the Crane Pond area suggeststhat this species is rea(lily adaptable to varying conl-li tionis.

9. The lack of suitable vegetation ind(luces an aj)pe-titive behavioral pattera in. which the turtles moveaibout until they comaneto an area containing the properveget'ation ty)e.

IJI TERATURE CITED

Beecher, W. J. 1-942. Nesting birds and the vegetationlsubstralte. (Chi(ago: Chliea1go Ornotlbological Society.

Breckenridge, W. J. 1955. Observations on the life

Ihistory of thle soft-slhelled turtle Triotiyx 'crVox, w\itl

esp)ecial referenice to growvth. Copeia: 5-9.

Breder, R. B. 1.927. Turtle trailing: a lnewv teclhique,for studying thle life Iial)its of certain testudniata.Zoologica 9: 231 -243.

Cagle, F. R. 1944. Home range, homing belhavior andinigratioll ill turtles. Mise. Publ. Mils. Zool. IUlliv.Mlich. 61: 1-34.

. 195). The life history of the slider turtle,

P'e/Isctdcmys .scrip~ta troo~sti (Holbrlook). Ecol. Mlollog.20: 831-54.

Cahn, A. R. 19837. The turtles of Illinois. Ill. Biol.

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Carr, A. & D. K. Caldwell. 19,5(. The ecology amlll nmi-

gratioms of seai turtles. I. Results of field work iiiFlorida, 1955. Amier. Mus. Nov. No. 1 7983: 1-283.

Carr, A. & Leonard Giovannoli. 1957. The ecology andmigrations of sea turtles, 11. Results of field \ork inCosta Rica, 1955. Amer. Mus. Nov. No. 18835: 1-32.

Casteel, D. B. 1911. The discriminative abilitV of the

pailitel turtle. .Jour. Aniimal Behaivior 1: 1-28.

Clark, P. J. & F. C. Evans. 1954. l)istance to iiearestneiglhbor ats ame1asure of spatial relationslips in

ol)opllltioiis. Ee ology 35: 445-453.-. )1955. Oi some as)pects of spatial p)attern in

biological l)olulatioils. Science 121: 397-398.

Dansereau, P. 1951. i)escription and recordinig of vege-taltioii tio)01 ai structural b)alsis. Ecology 32: 172-2239.-. 1952. The varieties of evolutionary op)povtuiiity.

Rev. Cainaid. (le Biol. 11: 305-88.



14() OWEN J. SEXTON }Ecological Monographs140 OWENJ. SEXTON ~~~~~~~~~~~~~~~~29, No. 2

Gould, E. 1957. Orientationl inl ')ox turtles, Terrapenec. carolina (Linnaeus) . IBiol. Bull. 112: 336-348.

Heape, W. 1932. Emigration, migration, and nomlaldism.

(Calmbidge: W. Ileffer n111(Sons Ltd. 369 pp.

Lagler, K. F. 1.943. Food lhibits and economic rela-

tions of thie turtles of Alichigani withi special reference

to fish mniaiigement. Amer. Midland Nat. 29: 257-312.

Legler, J. 1954. -N7esting habits of the western painted

turtle, Cirysciys pincta bollii (Grray). Ilerpetologiea

lo: 137-144.

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l)ox turtles. Copeia: 125-127.

Noble, G. K. & A. Braslovsky. 1935. The sensory

meclhaniism involved in the migration of newly hatched

freshi-waiter turtles. Aunt. iRec. (suppl.) 64: 88.

Parker, G. H. 1 922. Time crawling of young logger-

lme<(1X towar(1 time sea. Jour. Exp. Zool. 36: 323-331.

Pearse, A. S. 1923. The abundance and migration of

turtles. Ecology 4: 24-28.

Raney, E. C. & E. A. Lachner. 1942'. Summer food of

ChryIserys picta marginata iii Chautauqua Lake, New

York. Copeia: 83-85.

Sexton, 0. J. 1957. Notes (concerning turtle hatebllings.

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tionships of the box turtle, Terrapene c. carolina

(Linnaeus). Ecol. Monog. 20: 351 -378.

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Clareudon Press. 2'28 pp.

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Sexton 1959 Spatial and Temporal Movements of the Painted Turtle

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Transcript of Sexton 1959 Spatial and Temporal Movements of the Painted Turtle