57

THE SOUTH ISLAND OTTER - AN ADDENDUM

G.A. POLLOCK*

Sm.tMARY:Further reported sightings, some in new areas, are recorded and examined. Tentative

conclusions as to the animal's ecology and revised theories as to its zoological classification anddistribution throughout the island are suggested.

INTRODUCTION

An earlier paper (Pollock 1970a) traversed themOTe important evidence as to the existence ofthe controversial South Ishmd otter, suggesting ameans whereby it could have been introduced toNew Zealand and its possible zoologicalclassification and point of origin. Since that datenumerous other accounts, both old and recent,have come to hand, among which are several sodetailed and circumstantial as not only toreinforce my earlier conviction of the animal'sexistence, but also to suggest tentativeconclusions as to its characteristics, ecology andpresent distribution. The more important ofthese are set out in the present paper.

RECENTLY REPORTED StGHTINGS

I. Southland

In line with the trend of earlier reports manyof the recent accounts originate in or near theSouthland Land District. One of the mostimpressive is that of Bob Thompson of Dunedinwho, in December 1968, was occupying a holidayhut near the Whakaea river about half waybetween Waikaia township and Piano Flat. Nearit runs the Stevenburn, which, some 100 m abovethe hut, has been diverted towards it to run past,

and probably drain, a 10nJ>-disused milkingshed. He said he was awakened at daybreak bypossums on the roof and emerged to see ananimal come up out of the creek just below thepoint of diversion, look round very cautiouslyand then apparently signal to three others,estimated by him as three parts grown, for theyfollowed her up the bank and all disappearedbehind some shrubbery. He immediatelyrecognised them as otters, and his qualificationsfor so judging are excellent: he is an Englishmanwho lived for many years beside the River Yare inNorfolk, where otters abound.

* 18 Lansdowne Terrace, Christchun.:h

The movements of the otters, if otters theywere, can be logically explained. They couldduring the night have been fishing furtherupstream - part of a young otter's education;but returning towards the holt at daybreak themother sensed that the hut was occupied, so sheled her brood down the old dry channel to

by-pass the point of danger.

Admittedly this account may be open toargument, for there are ferrets in the vidnitywhich could possibly have been mistaken forotters. However, the behaviour pattern seemsmore characteristic of otters and supportsThompson's identification.

A more recent report appears open to no suchobjection. Early in 1971 P.J.A. Bradley, a Timaruresident well versed in New Zealand wildlife, wasshooting for deer in the bush near the right bankof the Hollyford river below the confluence ofthe Pyke. When conditions in the bush becametoo dark for effective stalking he made his waytowards the river to wait for the jet boat that wasto pick him up; but as he approached he heard aconsiderable splashing in a backwater, so hecrept quietly towards the spot. There he saw ananimal climb the bank then slide down as if in

play; he watched for about fifteen minutes,during which the performance was repeatedfour or five times. Though Bradley claimed nofirst hand knowledge of otters, the closeness andduration of the observation, coupled with thequite distinctive behaviour pattern, carryconsiderable conviction. His description too wasgood: he said the animal had a very thick tailstreamlined on to the body and tapering; legsshort and thick; fur dark brown, apparentlyshort and snooth; head small in relation to thebody, with no noticeable neck or ears. The lengthoverall he estimated as from 36 inches (91.4 em)to 42 inches (106.7 em).

58 PROCEEDINGS OF THE NEW ZEALAND ECOLOGICAL SOCIETY. VOL. 21, 1974

2. Canterbury.

Meantime the other main traditional hahitat

(Canterbury, south of the Waimakariri) has notlacked reports, but of these I will quote three

only, since in each case the observer sharedThompson's qualification - first handk110wledge of otters in Britain. One, from a builtup area of Ashburton, is remarkable assuggesting that the New Zealand animal, thoughsecretive in habit, is not necessarily over-wary ofpopulous places, resembling in this respect theotter of Britain (Stephens 1957). In .June 1968(or 1969) at about 1515 hours Mrs K. Font waswalking with her children to the shops in CreekRoad, which there crosses, by a culvert-likebridge, the small Wakanui stream. One of thechildren, looking downstream from the bridge,drew her attention to a swimming animal; thisshe immediately pronounced an otter, for theresemblance to otters she knew was so great thatno alternative occurred to her. The stream leads,a few chains further down, through a disusedmillpond, now a heavily overgrown swamp. whilefurther up a feasable route from the Ashburtonriver (north branch) can be traced.

Again there is an element of doubt, for whenquestioned later,she conceded that what she hadseen could have been a ferretorfitch; she was notaware that in New Zealand many of these, in the

wild state, show marked polecat characteristics.

Nevertheless the probabilities favour her firstjudgment, for while fitches will certainly enterwater after prey they are most unlikely to favoura stream as a means of travel.

The other reports, from J.W. Mason ofTimaru, leave no room for any such confusion;in fact the first is in my opinion worthy to rankwith the tracks seen by Haast (Pollock 1970a) aspractically conclusive proof. On a warm sunnyafternoon in late January 1970 he was driving hiscar along the left bank of the Opihi river belowTemuka towards a favoured fishing hole when,

approaching the end of the track, he saw ananimal feeding on a grassy bank. Leaving his carhe walked towards it to a distance of about fivemetres, the animal meantime watching himapproach. He was positive it was an otter, for hewas close enough even to see the interdigital webon its forefeet. Then it made off through scrubby

growth towards the river, where he lost sight ofit.It was, he said, an adult, about 30 inches (76 cm)from nose to tip of tail; colour between raw

umber and burnt sienna, and when he returned

to see what it had been eating he found half of a

freshly caught eel.

The next year, on a stormy night in August, ashe was approaching the Arundel bridge from the

north, a similar animal crossed the road in thelights of his car and stood watching him from theverge; this too he was certain was an otter. Hisqualifications to judge could hardly be better; hehad spent much of his life near the Nene andOuse, two of the most frequented rivers inBritain, and had seen many otters there.

3. The Taieri Plain.

Between the Clutha and the Opihi lies a tractlong devoid of reports, so, having regard also tothe bare open nature of much of the interveningcountry, it seemed to me unlikely that therecould now be any communication between thesouthern and Canterbury populations asdeduced from earlier sightings. However, recentdiscoveries on the extensive swamp between andto the west of Lakes Waipori and Waihola renderthis much less certain. Of the total area of about800 ha over a third, including Ram Island (one ofthe few prominent features), is owned by HoraceSinclair of Outram. Though the swamp iscontinuously under water, with many lagoons ofvarying sizes, it is possible to graze cattle overmost of the area, for there is a solid bottom lessthan one metre down; in fact some decades ago a

large part was enclosed in stopbanks, pumpeddry and cultivated; but now the main vegetationis rushes, raupo, niggerheads and aquaticgrasses. Probably only Sinclair himself has everbeen over the whole area in recent years. Inseason he is there in search of ducks, and laterwhitebait, but his interest is not confined to theseas he is an enthusiastic and knowledgeableamateur ornithologist.

At about 1030 hours on the first Saturday in

June 1970 he was traversing, with gun in hand,the swamp near the south end of Ram Islandlagoon, when an animal exploded from a smallpool and made off with an undulating motionover some firm ground. He thought at first it was

THE SOUTH ISLAND OTTER - AN ADDENDUM

a rat (Rattus norvegU:us) and being an instinctive

shooter raised his gun and fired; however even ashe pulled the trigger he realised it was no rat butan animal he had never seen before: With a

companion he searched the spot where it shouldhave been but found nothing - not evenbloodstains; and it may be noted that, except at

very close range, an otter's fur and skin are most

resistant to shotgun pellets (Stephens 1957).

Though he had only a rear view he was able todescribe several significant features. The bodyseemed barrel-like, from 10 to 13 cm indiameter; length up to 30 cm head and body-50 cm over all. (These latter dimensions, fromthe angle of sight, would be the hardest toestimate with accuracy.) Colour was intermediate

between dark shades of raw umber and sepia, butmuch lighter (say raw sienna) on the underparts.However, the most positive characteristic was thetail - tapering, much thicker than that of a ratand exactly as portrayed in various photographsof Lutra lutra subspecies.

On 26 April 1971 Sinclair and a friend IanBruce had occasion to inspect a drain 1eadingacross the swamp from high ground, about 700m from the point ofthe original sighting. Near itssource this had dried out to viscous mud, onwhich they found numerous footprints, aboutthe size of a matchbox, which exactlycorresponded to tracks ofLutra lutra as described

in an article (Pollock 1970b) which had that verymorning been read in a farming radio session.These were unmistakable, for on some -even theinterdigital web was clearly apparent.

Often on clear still nights they had heard overthe swamp the "plop" of some creature as it

splashed in the pools; this seemed much too loudfor either eel or trout. They were never able tosight the animal but did on occasion see veryextensive ripples.

Sinclair said also that, near the point where theold broken stopbank runs down to a wide deepbranch of the Waipori river, he had observedseveral well defined and obviously well usedtunnels through the rank grass and other densevegetation. In April 1973 I had an opportunity ofinspecting these. Ram Island itself can bereached only by rowboat; from there the

59

stopbank forms a rather precarious path to theriver - one most unlikely to be used by mainlyterrestrial animals such as possums or ferrets;indeed it may be noted that no ferrets have beenknown even on the island for many years.

One of the tunnels was soon found; it led downfrom the bank through a rush of giant

proportions, and on parting the reeds to inspectit I found the tunnelled along under the bankout of sight; in one place it had been enlarged byexcavation. About one metre further on I partedthe reeds again, this time from the lower side, tofind a well-defined chamber about 0.5 m longand half that in diameter. It was much too big fora rat's nest, and in any event there was no trace ofthe dry grass with which rats commonly line theirnests. Immediately above the chamber anotherbut less used tunnelled vertically to the top of thebank - probably as an emergency exit. Thecomplex had all the characteristics of an otter"holt", and it is hard to imagine any other

creature likely to have constructed it in suchdetail. The vertical entrance tunnels, excavationand above all the total lack in the chamber of anylining material, feathers or down eliminated, in

my opinion, any possibility that it had been thelest of any species of duck.

Bruce, during the 1973 shooting season (May)was rowing across Ram Island lagoon to his"maimai" (shooting blind) set some distance out

from the western bank, which was clothed indense raupo. It was before daybreak, so nothingwas seen, but twice a swimming animal of somesize seized his paddle, then released it; twice alsoit bumped the bottom of his boat beforeswimming away. At the same spot both Sinclairand Bruce often heard from the maimai a veryconsiderable splashing behind the raupo, as iffrom an animal at play. Though once they rowedcautiously towards the spot, nothing could beseen and the noise had ceased.

Other observations made by Sinclair includedtracks and possible spraints on the stopbankbetween the island and the river, grass twisted upinto "sign heaps" as described by Stephens (1957)and a beaten path across a tongue of Ram Islandon a route unlikely to have been followed by anycreature known to frequent the area.

60 PROCEEDINGS OF THE NEW ZEALAND ECOLOGICAL SOCIETY. VOL. 21, 1974

PHYSICAL CHARACTERSTICS

From the further sightings reported it is nowpossible to reach some tentative conclusions as to

the animal's external characters. While these areconsistent generally with those of the genus Lutra- particularly the species L. lutra - it wouldseem likely that any otter here would be smallerthan most other varieties; indeed, Tarawhata'sestimate (in Watson 1960) of two feet (61 cm)head and body and 40 inches (102 cm) over all is

about the maximum so far recorded; many quiteimpressive accounts show dimensionsconsiderably smaller. As for colour I have foundWinsor & Newton's artists' charts invaluable in

checking estimates; with a considerable degree ofunanimity these range, for the dorsal fur,between dark shades of raw umber and sepia. Incommon with otters generally, underparts are

usually lighter, though these have not alwaysbeen visible.

One or two variants are interesting; Tarawhata

spoke of a "grizzling" of the fur, while there aretwo reports, otherwise quite circumstantial, of

spotted or speckled animals. Three otheraccounts mention bright shades - raw sienna,cadmium yellow deep and even Naples yellow-but these I treat with caution; there is too great apossibility of confusion with the fitch, which inNew Zealand has been known to exhibit similarvariations (Wodzicki 1950).

POSSIBLE ZOOLOGICAL CLASSIFICA TtON

Haast's firm description of the tracks seen byhim as "exactJy resembling those of the otter of

Europe, only a little smaller" (Haast 1877, 1879)strongly indicates some species of genus Lutra;but I find I can no longer support my suggestion(Pollock 1970a) of L. (Lutrogale) persPicillata as apossibility; not only is that species too large, but itis never grizzled, while on the other hand ouranimal shows no sign of being gregarious. Of theL. lutra subspecies listed by Harris (1968) L. lutrabarang seems the nearest, except in point ofcolour; but a question arises - could we havehere a species or subspecies which, since itsintroduction say five centuries ago, has becomeextinct or nearly so in its native habitat? Theexample of the Parma wallaby (Macropus parma)on Kawau Island shows that this is at least a

possibility. Capture of a specimen -I hope alive- would solve many problems.

ECOLOGY

There are indications that the animal'secological characteristics may differ in somerespects from those of most members of speciesL. lutra. It seems extraordinarily mobile and, indistributing itself throughout the island, capableof traversing mountain passes or co Is up to 1100m or higher. When travelling away from water itcould rely as a staple diet on lizards such as theskink (LeioloPisma zelandica) - an item quitelogical, but so far as I am aware never recordedfor otters elsewhere in the world. This may be theexplanation for Tarawhata's view (in Watson1960) that there were two kinds-an aquatic oneeating fish and a land one living on lizards.

Recent evidence suggests that, in theCanterbury foot-hills at least, when the onset ofwinter causes much of their natural prey tohibernate, some of the animals may migrateconsiderable distances on to the plains, even asfar as the smaller streams feeding LakeEllesmere.

However, the most remarkable ecologicalfeature is the lack of conspicuous spraints. Haastapparently saw none, though he must havelooked, and in a diligent search of at least a dozenstreams I have had no more success. Wall (1926)and much later Harris (1968) treated this as amain argument against the animal's existence;but recent research in Sweden by Sam Erlinge(1968) removes most of its force. He considered

(I think correctly) that the ritual deposit of faeces

in prominent situations is not a compulsive, even

aimless, process but is in every instanceconsciously directed towards one or other of twopurposes - sexual and territorial - the latterbeing predominant; for he found that even asmall lessening of population pressures resultedin a dramatic reduction in spraints. Here (except

possibly in a few confined areas such as the Taieriplain) such pressures would be minimal; so thediscovery of spraints in any quantity would moreprobably indicate mating activity. As for normalbowel evacuation, it has even been suggested that

in the absence of signalling activity this could take

place in the water.

THE SOUTH ISLA:-m OTTER ~ AN ADDENDUM

DISTRIBUTION

The limits previously suggested (Pollock 1970a)now seem too restricted, for not only do we have

the recent accounts from the Waipori swamp. butthere are two, possibly three, quite persuasive

reports from northern Westland and Buller. Iwould now be reluctant to regard any area of theSouth Island as impossible or even improbable.

It is otherwise however with the North Island,V\'hence no repofts have ever come. This goes farto rehut the argument of critics such as Wall(1926) and WaIson (1960) that most if not all ofthe reported sightings were probably mistakesfor one or other of the smaller introducedmammals; for all of the alternatives suggested-be they rat, possum, stoat or ferret - 3re alsonumerous north of Cook Strait.

CONCLUSION

I conclude that this evidence, coupled with thatset out in my 1970 paper, isprimafacw proof, notonly of the existence of the "waitoreke", but of itssurvival to this day. Of the fields for furtherinvestigation obviously the most promising is theWaipori swamp on the Taieri plain; but thoughSinclair and Bruce ar~ doing as mu!=h as possible,they cannot be contmuously on the spot, andnothing short of this is likely to produce moretangible results, particularly the capture of aspecimen, By "capture" I mean just that, for as aconservationist I could not tolerate the

destruction of a rare animal merely to prove it

61

had once lived. Bradley, with rifle in hand, didindeed have this opportunity; that he refrained isI think greatly to his credit.

REFERENCES

ERLlNGE,Sam1968. TerritorialityohheotterLutra lutralutra.

Oill.O.519: 81, 84.

HAAST.J. von 1877. Presidential address to Canterbury

Philosophical Institute. Transactions of New ZealandInstitute 10: 44, 48.

HAAST.j. von 1879. Geology of the prov'lIlces of Canterburyand Westland, New Zealand. pp. 427-429. Times office,Christchurch.

HARRIS,c.J. 1968. Otters. Weidenfeld & Nicolson, London,

p. 73 and Appendix B.

POLLOCK. G.A. 1970a The South Island otter - areassessment. Proceedings of New Zealand Ecological Society17,129-135.

POLLOCK,G,A. 1970b. Find the otter. Tussock Grasslands and

Mountain Lands Institute Review 20: 66.

STEPHENS. Marie 1957, Natural history of the otter ("OUer

Report") pp. 10, 16, 17,24,34, University Federation of

Animal Welfare, London.

WALL.A. 1926. The mythic otter of New Zealand. The Press,

Christchurch, 8 Sept.

WATSON. J.S. 1960. The New Zealand "otter". Record5 (if

Canterbury Museum, Christchurch 7: 175-183,

WODZICKI.K.A. 1950. Imroduced mammals of New Zealand,

New Zealand Department of Scientific and Industrial Researrh

Bulletin 98: 69.