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Recognizable Forms

Subspecies of the Dark-eyed Juncoby

Ron Pittaway

IntroductionThe Dark-eyed Junco ijunco hyemalislis comprised of many forms that arerecognizable in the field. Just take alook at the six forms of the Dark-eyed Junco illustrated on page 403 ofthe National Geographic Field Guide[Scott 19871. Before they werelumped by the AmericanOrnithologists' Union (AOU 19731.Ontario birders eagerly checked themigrant and winter flocks of Slate-colored Juncos U. hyemaliss forOregon Junco U. oreganusl. Reports ofOregons almost ceased after 1973!Yet juncos are a good example ofwhy birders should look atrecognizable forms. By looking just atspecies, we are limiting ouropportunities of seeing interestingbirds and learning more about them.In the following, I describe theidentification features and occurrenceof the recognizable forms of theDark-eyed Junco in Ontario.

TaxonomyThe AOU Check-list (19571 listed thefollowing five species of juncos thatwere later lumped as the Dark-eyedJunco: (11 Slate-colored Junco U·hyemalisl; (21 Oregon Junco U·oreganusl, including the Pink-sidedJunco U. o. mearnsi); (3) White-winged Junco U. aikeni); (4) Gray-headed Junco U. caniceps), includingthe Red-backed Junco U. c. dorsalis);and (5) Guadalupe Junco U. insularis).

The two well-marked subspeciesincluded in the above were alsoformerly recognized by someauthorities as distinct species: thePink-sided Junco U. meamsil and theRed-backed Junco U. dorsalisI (Sibleyand Monroe 19901.

The AOU (19731 lumped all ofthe above species (except the Gray-headed junco] as the Dark-eyedJunco because they interbreed wheretheir ranges come into contact. TheGray-headed was later merged withthe others (AOU 19831. However,interbreeding is "minor in mostcases" according to GeorgeBarrowclough [pers. comm.] of theAmerican Museum of NaturalHistory. Michel Gosselin [pers.comm.] of the Canadian Museum ofNature stated that "the forms arequite distinct in most areas and this isborne out by specimens".

Currently, most ornithologistsfollow the Biological Species Concept(BSq which means that populationsthat freely interbreed, or if separated,could potentially interbreed with oneanother, are the same species.Recently, a new species conceptcalled the Phylogenetic SpeciesConcept IPSCl has been gainingwider aceeptance. The PSCrecognizes as separate species thosepopulations and subspecies whichhave distinctive traits and areevolving along separate evolutionarylines. The identifiable forms treated

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Figure 1: Slate-colored Junco. Drawing by Christine Kerrigan.

in this article are considered to bephylogenetic species (GeorgeBarrowclough, pers. comm.}.

For a list of the junco subspecies(races) in Canada see Godfrey (1986),and for Ontario see James (19911.

Plumages, Ageing and MoltsThe following describes the plumagesand ages of the Slate-colored Junco(hyemalis group]. The molts aresimilar in all forms.

Adult juncos (definitive basic]undergo a complete molt on thebreeding grounds before fallmigration takes place. Most adults(particularly females] in fresh fallfeathering are tinged with buff orbrown. The brownish feather tipslargely wear off by summer, resultingin a darker plumage.

ONTARIO BIRDS DECEMBER 1993

The streaked, sparrow-likejuvenile [juvenal] plumage is seenonly on the breeding grounds - seethe illustration on page 403 of theNational Geographic Field Guide[Scott 19871. Juveniles undergo apartial molt to first year (first basic Iplumage before autumn migration.First year birds are duller and moreuniformly brown than adults. Juncosretain their first year plumage forabout one year, after which they moltcompletely into adult plumage.

Slate-colored Junco:(J. h. hyemalis.group)This is the common form in theprovince. In winter, it frequentsfeeding stations in southern Ontario.

The Slate-colored Junco is madeup of three very similar subspecies:

nominate hyemalis of the borealforest; cismontanus of westernCanada; and carolinensis of theAppalachian Mountains (AOU 1957).In Ontario, James (1991) lists hyemalisas breeding in the province andcismontanus as an "occasional, rarestraggler, autumn to spring".Cismontanus is "similar to hyemalisbut hood more blackish, oftennoticeably darker than back; backmore brownish; females with sidesmore mixed with pinkish brown"(Godfrey 1966, 1986). The subspeciescismontanus intergrades with thesubspecies montanus of the Oregonform in Alberta and BritishColumbia, resulting in puzzlingintergrades.

Some female Slate-colored Juncosare difficult to separate from someOregon Juncos. In the Slate-coloredJunco, "usually there is someindication of slate colour near thejunction of the base of the hood withthe sides" (Godfrey 1966).

Oregon Junco:(J. h. oreganus group)In Canada, three very similar westernraces, oreganus, montanus, andshufeldti, form part of a subspeciesgroup formerly known as the OregonJunco (Godfrey 1966). (The Pink-sided Junco, meamsi, is often groupedwith the above, but is distinctiveenough to merit separate treatment.]James (1991) lists both montanus andshufeldti as "occasional, rare straggler,autumn to spring" for Ontario. Theonly Ontario specimen of OregonJunco in the Canadian Museum ofNature was collected at Kingston inMarch 1958. It has been identified asmontanus by Dr. W. Earl Godfrey(Michel Gosselin, pers. comm.]. Most

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specimens from the East have alsoproven to be of the widespreadmontanus; for example, in New YorkState, Bull (1974) lists four specimenrecords of montanus and Tufts (1986)lists montanus from Nova Scotia.

Adult male Oregon Juncos (withtheir convex black hoods, chestnutbacks and scapulars, and rufoussides) are easily recognizable. SeePlate 72 in Godfrey (1986). Adultfemales are duller with grayer hoods.Some female Oregons areoccasionally misidentified as Pink-sided Juncos, mearnsi, but Oregonsgenerally have darker, morecontrasting hoods and lack thecontrasting blackish lores of the Pink-sided. See the illustrations on page403 of the National GeographicSociety Field Guide (Scott 1987).

First year (first basic) femaleSlate-colored Juncos of the subspeciescismontanus often have pinkish sidesand brownish backs and aresometimes difficult to distinguishfrom Oregon Juncos. With Oregons,"note that the dark hood on thebreast tends to turn up on the sidesof the breast and does not extendonto the sides; on the Slate-coloredJunco this turns downwards on thesides of the breast onto the sides"(Godfrey 1966). Confusingindividuals are best just called Dark-eyed Juncos.

Pink-sided Junco:(J. h. mearnsiJThe Pink-sided Junco is usuallygrouped with the Oregon Junco groupof subspecies (AOU 1957, Godfrey1966). It is considered to be aphylogenetic species and therefore istreated separately here.

James (1991) states that "mearnsi

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has been reported as sighted inOntario, but no specimens confirmthis". Pink-sided Juncos have alsobeen reported in Quebec (Miche1Gosselin, pers. comm.) and NovaScotia (Tufts 1986). However, mostreports of Pink-sided Juncos in theEast probably refer to pale femaleOregon Juncos. Pink-sidedJuncos(sexes similar) are bestdistinguished from female Oregons bytheir paler blue-gray (in the field)hoods and contrasting blackish lores,grayish brown backs and morepinkish sides (brighter than back).Refer to the illustrations of Pink-sidedand female Oregon juncos on page403 in the National Geographic FieldGuide [Scott 1987).

White-winged Junco:If. h. aikeni)The White-winged is the largest andpalest of the juncos (Miller 1941). Itbreeds in the Black Hills of SouthDakota and adjacent mountainousareas.

The White-winged Junco hasbeen reported in Ontario on anumber of occasions, and it wasadded to the Ontario list [Baillie1964) based on a specimen collectedin Metropolitan Toronto(Scarborough) on 1 January 1964(ROM 93625). However, thisspecimen was examined by EarlGodfrey and determined to be aSlate-colored Junco with "abnormalwhite wing bars"; it also did "notmatch a White-winged Junco in theamount of white in the tail or insize". It was subsequently removedfrom the Ontario list [Baillie 1965).The above record was also reportedin Bent (1968).

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Slate-colored Juncos "occasionallyshow a slight presence of white wingbars" (Earl Godfrey, pers. comm.) .and some White-winged Juncos lackwhite wing bars (Miller 1941).Typical White-winged Juncos arebigger and a paler gray (ashy) colourthan Slate-colored Juncos, with morewhite in the outer tail feathers(usually first three and part of fourthon each side). The Slate-coloredJunco usually has two white outer tailfeathers and the third is partiallywhite. (Miller 1941, Bent 1968,Oberholser 1974).

Gray-headed Junco:If. h. caniceps.group)Godfrey (1986) lists two Canadianrecords of this distinctive junco of thewestern United States. Both recordsare of the more migratory northernsubspecies, caniceps. This beautifuljunco is illustrated on Plate 72 inGodfrey (1986).

A Gray-headed Junco (sexessimilar) was found and photographedin colour at Point Pelee on 9 May1989 by John and Ginny Kreest (AlanWormington, pers. comm.). It wasreported in the sightings book at thepark but apparently no one went tosee it. Ten years earlier, when it wasconsidered a full species, it wouldhave caused a stampede! I examinedthe photograph of the Point Peleebird (courtesy of Alan Wormington)and its pale upper mandible is clearlyevident, indicating]. h. canicepsrather than the more southerly andless migratory Red-backed Junco If·h. dorsalis) which has a dark uppermandible. See the illustrations ofthese two subspecies on page 403 inScott (1987) and on page 333 inPeterson (1990).

SummaryThe Dark-eyed Junco is made up

of several rather distinct subspeciesand groups of similar subspecies thatwere formerly considered to beseparate species. They are treatedhere as identifiable forms of theDark-eyed Junco. Intergrades occur,but because of sharp dines betweenpopulations, most forms are quitedistinct and recognizable in the field.For additional information, the readeris referred to Bent (1968) and Farrand(1983).

AcknowledgementsI wish to thank Bob Andrle, GeorgeBarrowclough, Dan Brunton, BillCrins, Bruce DiLabio, Earl Godfrey,Miche1 Gosselin, Jean Iron, Ross[ames, Chris Lemieux, Ron Tozer,Mike Turner and Alan Wormingtonfor assistance and comments.Christine Kerrigan kindly did theillustrations of the Oregon Junco(cover) and Slate-colored Junco.

Literature citedAmerican Ornithologists' Union. 1957. Check-

list of North American Birds, 5th edition.American Ornithologists' Union,Washington, D.C.

American Ornithologists' Union. 1973. Thirty-second supplement to the AmericanOrnithologists' Union Check-list of NorthAmerican Birds. Auk 93: 875-879.

American Ornithologists' Union. 1983. Check-list of North American Birds, 6th edition.American Ornithologists' Union,Washington, D.C.

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Baillie, J. L. 1964. Ontario's newest birds.Ontario Field Biologist 18: 1·13.

Baillie, J. L. 1965. Ontario's bird list:subtract one; add one. Ontario FieldBiologist 19: 41.

Bent, A. C. 1968. Life Histories of NorthAmerican Cardinals, Grosbeaks, Buntings,Towhees, Finches, Sparrows, and Allies.United States National Museum Bulletin237, Part 2.

Bull, J. 1974. Birds of New York State. TheAmerican Museum of Natural History.Doubleday/Natural History Press.

Farrand, J. F. Jr. {Editor}. 1983. The AudubonSociety Master Guide to Birding. Volume 3Alfred A. Knopf, New York.

Godfrey, W. E. 1966. The Birds of Canada.National Museum of Canada Bulletin 203.

Godfrey, W. E. 1986. The Birds of Canada.Second Edition, National Museum of Canada,Ottawa.

[ames, R. D. 1991. Annotated Checklist of theBirds of Ontario. Second Edition. LifeSciences Miscellaneous Publications, RoyalOntario Museum, Toronto.

Miller, A. H. 1941. Speciation in the AvianGenus Junco. University of California Press,Berkeley.

Oberholser, H. C. 1974. The Birdlife of Texas.Volume Two. University of Texas Press,Austin and London.

Peterson, R. T. 1990. A Field Guide to WesternBirds. Houghton Mifflin Company, Boston.

Scott, S. L. {Editor} 1987. Field Guide to theBirds of North America. National GeographicSociety, .Washington, D.C.

Sibley, C. G. and B. L. Monroe Jr. 1990.Distribution and Taxonomy of Birds of theWorld. Yale University Press, New Havenand London.

Tufts, R. W. 1986. Birds of Nova Scotia.Third Edition. Nimbus Publishing Limited,The Nova Scotia Museum, Halifax.

Ron Pittaway, Box 619, Minden, Ontario KOM 2KO.

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