tcz K. Green and V- Wong: Winterdiet of Gentoo penquin Corella16(5)

Klages, N. T. W., Pemberton, D. p. and Gales, R. (1990). Volkman, N. J., Presler, P. and Trivelpiece, W. (1980). Diets The diets of King and penguins Gentoo at Heard island- of pygoscelid penguins at King George Island, . Aust. Wildl. Res. 17: 53-60. Condor 82:373-378. LaCock, G. D., Hecht, T. and Klages, N. (1984). The winter Williams, A. J. (1980). Aspects of the breeding biology of diet of Gentoo Penguins ar Marion Island. Osrrjcft 55: the Gentoo Penguin, Pygoscelis papua. Gerfaut 70: 188-191. 283-295. Mauchline, J. (1980). Measurement of body length of Williams, R. and McEldowney, A. (1990). A guide ro rhe Euphausia superba Dana. Biomass Handbook 4: l-9. otoliths from waters off the Australian Antarctic Territorv. Patterson, G. B. (1986). A statistical method of testing for Heard and Macquarie Islands. ANARE Research Notes dietary differences.N.Z. J. Ecol.13: 113-115. 15. Ridoux, V. (1988). , Euphausia vallentini Williams, T. D. (1991). Foraging ecology and diet of Genroo Stebbing, preyed upon by penguins around Crozet Island Penguins Pygoscelis papua at South Georgia during winter (Southern Indian Ocean): population structure and annual and an assessment of their winter prey consumption. lbls cycle. "/. Plank. Res. l0: 675-690. 133:3-13.

Corella,1992, 16(5): 132-133

LONGEVITYOF CAPE PETRELSDaption capense AT BLUFF ISLAND,VESTFOLD HILLS, EAST ANTARCTICA

F. I. NORMAN and S. J. WARD1

Department of Ecology and Evolutionary Biology, Monash University, Clayton, Victoria 3168. 'preient addrcss: Depar-tment of Zoology, James cook University, Townsville, Queensland 4811.

Received24 September, I99l

The Cape Daption capensenests on the Bluff Island was visited briefly in early .on Antarctic and Subantarctic February1989 and again,for a longer period, on islandsas well as on the continentitself (Watson 7 Januaiy 1991during studieson the SouthPolar 1975; Marchant and Higgins 1990). Breeding SkuaC aihar ac ta mac c o r micft i. Previously-ban ded occursin East Antarctica,including sites in Prydz CapePetrels were noted in 1989.In 1991petrels Bav (Woehlerand Johnstone1991). Bluff Island at nestsover muchof the Islandwere examined, '77'54'E), density was high and 1Of::'S, off Davis Station in the particularly where nest Vestfold Hills, is one such nesting area where where bandedprior to 1989were breeding. Cape have been banded intermittently Ot 334 adults caught at nest sites, 15 had been sinie 1959.To the endof the 1989i90summer 299 banded previously.Four adults were banded in oulli and 130 adult birds at nests have been 1989.one breedingadult was banded as a chick markedthere. in February 1974ind anotheras a pullus in 1984; December,1992 F. L Noinan and S. J.l{afd. Longevityof Cape Peirel 133 a further adult had been bandcd as a nestling at than strict philopatry (e.g. Pinder 1966;Marchant the Forbes Ctacier (67'38'3. 62"21'E). some R00 and Higgins 1990). The recapture of an adult km away near Mawson in February 1973. Eight Cape Petrel at Bluff Island originally banded adults were banded on nests in February 1984, (with a monel band) as a chick near Mawson when 68 pulli and 32 breeding birds were marked indicatesthat some birds do dispersefrom natal by K. Green. siles lo hreed clscuhere, somelimeso\er con- siderabledistance. Pinder (1966) noted that 5-16 Sincc Cape Petrelsare essentiallymonogamous, per cent of the breeding population was replaced in with a long-lastingpair bond, and show a strong any onc year and hencc estimatedadult mortality fidelity to nesting areas (Marchant and Higgins for Capc Petrels at Bluff Island may reflect both 1990),such rccapturedata may provide a measure death and emigration. Such cstimates may be of minimum survival and henceannual mortality. biasedfurther by failure of nestingattempts early Minimum mean annual survival (S) may be in the breeding season, and the subscquent calculated as S = (r/n)L/ror, as a percentage,as dispersalof adults. At breeding colonies such as S = 100.i4/n. where y numberof )cars. n : Bluff Island, blizzards and resulting snow drifts number originally banded, and r : number of could reduce nest site availability, ncsting attempts recaptures (e.g. Mougin 1975). Thus for the and success,and lead to abandonmentof nesting cohorl of adult\ mrrked in 1984,minimum mean colonies. Further studiesmay clarify such tssues. survival was 0.82 (827o) and hence annual mortality (m) 0.18 (18'1,). Life expectancy(E) :2-ml2m ACKNOWLEDGMENTS (200'm/2m in percentage tbrm) and, in con- We thank the Dircctor, Australian Antarctic is some five years for such adult birds sequence, Division for the opportunity to visit BlutT Island, that mortality is independent of age. assuming and to the Station Leadcr and fellow expedition- limits about such estimatesare, how- Confidence ers at Davis during the 199011991summer for ality estimatesfrom these data, evcr, large; mo their assistancein many ways. Annie Wessing and 28 per cent. for example, vary between 12 helped in the exrminalion of the Bluff Island bircis and J. M . Cullcn, W. B. tmison and Conclusionsfrom these data are limited both anonymousreferees commented helpfully on the by the small numbers of banded birds in the manuscript. We are grateful too to the previous original cohort and their subsequentrecaptures. ANARE^expeditioneis who banded Cape Petrels In Addition, mortality estimatesmay be magnified on Bluff Island, and thank the Australian by band loss (presumably minimized by the use and Bat Banding Scheme who provided the of stainless steel bands from 1984 onwards), appropriate details. the non-recapture of previously-marked birds (reduced here by the coverage of the Island in REFERENCES areasof previousbandings) and emigration. How- ever, Mougin (1975) reported some 2l per cent Beck,J. R. (1969).Food, moull and age of lirslbreeding in of marked birds at the same nest sites six years the Cape PigeonDaPlion capensisLlrnaers Bti! Antarct. later and in this study at least 25 per cent of adult Surv. Bull. 21.3344. (1966).Adult survivalcstimates for two antarctic present Hudson,R. '73 birds banded on Bluff Island in 1984were petrels.Brlt. Antarct. Surt'.Bull. 8:63 there in 1991, seven years later. Estimated Marchant,S. and Higgins,P. (1990).(Eds).'The Handbook mortality rates are, however, somewhat higher of Australian,New Zealandand Antarcticbirds' Vol I than 4J per cent previously reported (Hudson (OxfordUniversity Press: Melbourne.) (1975). dc! 1966; Mougin 1975), and life expectancycorres- Mougin.J. L. EcologiccomparEe ct subantarctiques.C.N.F.n,4- 36: I 195. of 68 chicksbanded antarctiques pondingly less.That only one Pinder, R. (1966). Thc Cape Pigcon. DaPtion .apensts in 1984 was recaught as a breeding adult could Linnacus,at Signy lsland, Soulh Orkney Islands Blir' suggestheavy mortality of such chicks that season Antarct. Surv. Bull. 8: 1947. 'Birds (or subsequentprebreeding mortality). However, Watson, G. E. (1975). of the Antarctic and sincethe majority of birds breed for the first time Subantarctic.'(Amer. Geophys.Union: Washington ) Johnstonc.G. W. (1991)The statusand years age (Pinder 1966; Beck Woehler.E. J. and at about five of conservationof dre seabirdsof the AuslralianAntarclic 1969) and hence would have been available for Territory. ln status and conscrvation:a supPle- capture in 1991, it may also indicate some dispersal ment.' (Ed. J. Croxall). ICBP TechniculPubli(.ttion rr: to brced at other sites (e.g. Beck 1969), rather 279-306.