S. Afr. J. Antarct. Res., Vol. 10/11, 1981 35
Fur seals Arctocephalus gazella and leopard seals Hydrurga leptonyx at the Courbet Peninsula, Kerguelen M.N. 'Bester Mammal Research Institute, University of Pretoria, Pretoria 0002
Non-breeding population size and composition of Arctocephalus from this area probably reftect the popttlaticn trend for the gaze !la on the C ourbet Peninsula of Kerguefen were determined whole archipelago. In addition, new information on the during January 1980. The approximately 589 individual~·. presence and distribution of Jeopard seals, outside the winter concemrated on the leeward east COilS!, is a marked inrrea.w• season, is provided. !1\'er 1968 and provides a baseline value to assess like~\' future changes. The possibility exists thG! A. gazel!a breed1· elsewhere Study Area on rhe archipelago, and that Hydrurga leptonyx occurs year The Kerguclcn archipslago (49 IS'S, 69 30.E) lies on the 1'0111/d. Antarctic Convergence in the South Indian Ocean, the main island and associated islets having a combined area of 7 215 Nie-telende hei'O!k inr;sgroof!e en samestellinr; van Arctocephalus kn1' with a coastline of 3 000 km. Me:m annual air tempera gazel!a is hepaa! op die kus mn die Courbet skiereifand I'G/1 ture is 4,4 C westerly winds predominate, and rainl'all is Kerguelen r;edurende Jmmarie 1980. Die ongeveer 589 individue, evenly distributed over 250 to 300 days of the year. A descrip gekonscntrecr op die lywaartse ooskus, is 'n opval!ende toename tion of the main study are.'!- the Courbet Peninsula which sedert /968, en voorsien ·n ba.1·islyn waarde om moont/ike has a 267 km coastline, appears in Angot { l954). toekomstige veranderinge re beraam. Die moo/11/ikheid bestamt dm A. gazella elders op die argipel tee!, en dot Hydrurga Methods leplonyx dwarsdeur die jam· \'Oorkom. From 14 October to 23 December 1979 the southern and southeastern beaches of the Courbet Peninsula, from Point Introduction Molloy to Cap Digby, were regularly searched by two obser The Kerguelen fur seal Arctorepha/us gaze/fa occurs on islands vers on foot. The entire Courbct coastline. excluding small between the Antarctic Converge11ce and 60'S latitude (Bonner stretches in the south and northwest KERGUj;:LEN ARCHIPELAGO TN CAP NOIA I COTE DES GORFOUS DORES ~AP DE CHARTRES POINT SCOTT CAP DIGBY ANSE BETSY MOANE VERT RIVIEAE DU NORD CAP SANDWICH COURBET PENINSULA CAP RATMANOFF 01234';6 Kll-0~1ETRES ISTHME DU LAC POINT CHARLOTTE POINT MOLLOY '\) POINT MORNE >20 FUR SEALS 0 MORBIHAN GULF NOAVEGIENNE BAY • 10 • 20 FUR SEALS ~ POINT DE L'ETOILE * LEOPARD SEALS POINT SUZANNE NON-CENSUSED AREAS Fig I. The thstributiun uf fur ;ea!~ and h::npard -;eah on the Courbe! Peninsula during January 1980. Scott (one at Mornc Vert during mid-Decembcr) had fresh wounds, typical of those sustained in territorial conflicts (Bonner !968) although no territories were being maintained anrJ no breeding was taking place. Ten large, presumably adult, leopard seals of both sexes Table 1 were seen between Ansc Bctsy and Cap Cotter (8 to I I suits of a ccn;us of A. go::el/a during January 1980at the Courbet January), four together on a small sandy beach, the remainder RC Kerguclcn (AM=adu!t males, AF-adult female>). occurring singly on low rocky platforms and dense kelp beds ( Durl'il/ea sp.) in front of the large macaroni penguin Eudyptes Jmma- cluyso!op/m.l· colonies along the COte des Gorfous Dorts Date Locality AM AF tures Total -- (Fig. 1). 8.01.80 l3aie Charrier-Point Scott 11 () 3 !4 9.0!.80 Point Scott-Riviere du Nord 11 0 l 12 9.0!.80 Riviere du Nord-Anse Belsy 3 0 2 5 Discussion 10.01.80 An;e Bet;y-Cap de Chart re> 2 0 3 As on Heard Island (53 oo·s, 73 30'E) the summer non- JO.D!.80 Cap de Chanres-Cap Rollge 6 0 5 11 breeding population of A. ga::elk1 on the Courbel Peninsula 11.01.80 Cap Rouge-Cap Cotter 14 0 !3 27 at Kerguelen is increasing, and the presence of three black J 1.01.80 Cap Concr-Cap de Rohan 44 I 115 160 11.01.80 tap de Rohan-Cap Noir 2! 0 77 pups and six adult females at Point Suzanne in November 12.01.80 Cap Noir-Cap Digby s l 26 "35 !976 and 1977 (M. Pascal in fill.) may indicate the start of a 12.01.80 Cap Digby-Cap Sandwich !5 0 137 152 similar small indigenous breeding population although none ! 2.01.80 Cap Sandwich-Cap Ratmanofr 3 0 19 22 occurred in the present study. 13.01.80 Cap Ratmanoff-Point Charlotte 0 0 s A. gaze/la populations at high latitude islands in the South 13.01.80 Point Charlotte-Point Morne I 0 15 16' Indian Ocean (Heard Island, McDonald islands and Kergue- 3.01.80 Point de !'Etoilc-Point Suzanne 2 0 24 26 !en - this study), appear to favour sheltered beaches on the Total 141 2 446 589 leeward east side of the islands, avoiding, to a large extent, ------rocky ground as well as otherwise favourable vegetated areas 8. Afr. J. Antaret. Res., Vol. 10/11, 1981 37 ,)n the windward side (Budd 1970, 1972). As the majority of References rur seals on the Courbct Peninsula were immature and born elsewhere, it seems that the non-breeding Courbct Peninsula ANGOT, M. 1954. Observation sur les mammifi:res marins de population forms part of a greater "Kerguelen Archipelago .. l'archipel de Kcrguelen- avec une Ctude dC:taiiiCe de I' CICphant poplllation with an, as yet, unfound breeding colony site. de mer, iVfiroungn leonina (L.). Jfnmmalin !8: 1-111. With injured adult males oecurri ng in the northwestern sector, BESTER, M.N. 1979. A note on winter ~eal observations in the South Atlantic pack ice. S. Aji·. J. Antarcr. Res. 9:27-28. presumably injured through intrasexual fighting and possibly evicted from a nearby breeding colony site{s), and a small BONNER, W.N. 1968. The fur ~ea! of South Georgia. Br. Aware/. Sun. Sci. Rep. 56: 1-SL concentration of l"ur seals persistently occurring at Port Christmas (northern tip of the northwestern sector of the BONNER, W.N. !976. The statu> oft he Antarctic fur seal Arctoce plwfus gaze/fa. FAO Advisory Committee on Marine Resources Main island, Fig. 1) in previous years (To!lu 1967. R. Lesel Research, Scientific Consultation on Marine Mammals, Bergen, in lit!.). a breeding colony site may be situated in the lee of Norway. ACMRR;MM/SC:SO. the northwestern sector of Kerguelen. BUDD. G.M. 1970. Rapid population increase in the Kerguelen The A. gu::e/fa populations at Heard and McDonald islands fur seal, Arctocep!rafw rropica/is gm:efla, at Heard Island. ,\1mn within the range of these winter dispersing seals (Pay ne 1979a, malia 34:410-414. Bester 1979) may contribute to tile immature segment of the BUDD, G.M. 1972. Breeding of the fur ~;ea! a1 McDonald islands. Courbet summer population. It is interesting to note that small and further population growth at Heard Island. Aiammalia immatures. tending to disperse more widely than adults and 36:423-427. underrepresented on breeding colony sites during the breeding BUDlJ. G.M. & DOWNES. M.C. !969. Population increase and season (Banner 1%8), are practically absent from the 3 000 breeding in the Kerguelen fur seal, Arctocephnlus 1ropicalis strong population at Heard Island at a concomitant time ga::e!/a, at Heard Island. /IIammalia 33:58-67. (Budd 1972). The small one-year-olds in the present study CONDY. P.R. 1978. Distributiun, abundance, and annual cycle were not pathological specimens, but were estimated to be of fur seah {Arcroceplwfus spp.) on the Prince Edward islands. below and at the low end of normal body size and weight S. Afr.J. Wild/. Res. 8: 159-!68. variation for this age group at South Georgia (Payne 1979b). HOF~JAN. R.J., REJCHLE, R.A., SJNtFF, D.B. & J\.HJLLER In contrast to previous reports, leopard seals were observed SCHWARZE, D. 1977. The leopard seal (Hydrurgu/eptrmyx) at at Kerguelen during mid-summer. Since leopard seals occur Palmer Station, Antarctica. In; Adaptions Within Ant::trctic Eco during December (R. LCsel in /iu.), January (this study) and >y~tem<;. ed G.A. Llano. Smithsonian Institution. Washington D.C. March (Angot 1954) at Kerguelen, and therefore presumably in February and May too, a year round presence at Kerguelen, lNGHAM, SUSAN E. 1960. The status of seah (Pinnipedia) at Australian Antarctic stations. Mamma/iu 24: 422-430. similar to Heard Island (lng:ham !960) is indicated. Their KING, JUDJTH E. !959. A note on the specific name of the presence during summer, and close to penguin breeding Kerguelen fur seal. !liammu/io 23: 381. colonies, is probably related to feeding, leopard seals being I'AUUAN. P. 1952. Sur la prbence aux Jlc~ Kerguelcn d'Hydmr commonly found in association with penguins {Hofman go /eptourx (BI.) et d'Arcfocephah!s gaze/fa (Pet.) et notes bio er a{. 1977). logiques sur deu\ phocidCs. Mammalia 16:223-227. Acknowledgements I'A YNE. M.R. J979a. Fur >eals Arcroceplw/us rropimHr and A. gaze!/a crossing the Antarctic Convergence at South Georgia. This study formed part of a co-operative mammal research iHamma/iu 43:93-98. programme centred on pinnipeds in the Southern Ocean PAYNE, M.R. l979b. Growth in the Antarctic fur ~eal Arc/ace between French and South African researchers working plwlm; ga;;:t>/la. J. Zoo!., Lond. 187: 1-20. under the auspices of the Director of Scientific Laboratories REPENNING. C.A .. PETERSON, R.S. & HUBBS, C.L. 197J. of Terres Australes et Antarctiques Francaises (TAAF) and Contributions to the systemalics of the southern fur scab, with the South African Scientific Committee for Antarctic Research special reference to the Juan Fernandez and Guadalupe species. (SASCAR) respectively. I am grateful toT AAF for logistical In: Antarctic Pinnipedia; Antarctic Research Series 18: 1-34, support and SASCAR for llnancial support. The assistance ed W.H. Bur!. American Geophysical Union, Washington D.C. or Mr P.-Y. Lenglart. of Montpel!ier University, and members TOLLU, B. 1967. Rcconnais<;anccs systematique~ Ues cOte~ situCes of the 29th Mission to Kcrguelen are gratefully acknowledged. f.tl'e>t du mCridien 69'05'£. TAAF40: 21·63.