A juvenile Subantarctic fur seal Arctocephalus tropicalis was recorded on the Indian Ocean island of Rodrigues and two were seen on Mauritius. These records are at least 2 500 km from the closest breeding colony (Amsterdam Island) and are the most easterly by some 1 800 km of all previous records of vagrants of this species.Afr. J. mar. Sci. 25: 403–40

DAVID, J HM

SALMON, L

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On the morning of 11 July 2001, a small seal was dis-covered by a local inhabitant at Petite Butte on thesmall Indian Ocean island of Rodrigues (18 × 8 km;19°43´S, 63°38´E), approximately 560 km east ofMauritius. The seal was initially found about 10 mfrom the beach, on a small bank among Casuarinatrees. It then moved down onto the beach, where it layfor over an hour, in the heat of the day, shaded only bya rock overhang. The seal was later coaxed back intothe lagoon. It did not appear to be injured and soonAfr. J. mar. Sci. 25: 403–4052003403RECORDS OF THE SUBANTARCTIC FUR SEAL ARCTOCEPHALUS TROPICALISFROM RODRIGUES AND MAURITIUS, INDIAN OCEANJ. H. M. DAVID* and L. SALMON†A juvenile Subantarctic fur seal Arctocephalus tropicalis was recorded on the Indian Ocean island of Rodriguesand two were seen on Mauritius. These records are at least 2 500 km from the closest breeding colony(Amsterdam Island) and are the most easterly by some 1 800 km of all previous records of vagrants of thisspecies.Key words: Arctocephalus tropicalis, Indian Ocean, Mauritius, new record, Rodrigues, Subantarctic fur seal* Marine & Coastal Management, Department of Environmental Affairs and Tourism, Private Bag X2, Rogge Bay, Cape Town 8012,South Africa. E-mail: Jhmdavid@mcm.wcape.gov.za† School of Ocean Sciences, University of Wales, Bangor, Menai Bridge, Anglesey, LL59 5EY, U.K.Manuscript received September 2002; accepted March 2003Fig. 1  The juvenile Subantarctic fur seal seen on Rodriguesswam away.Early the following morning the same seal was dis-covered on some rocks at the south-east end of the is-land. It was captured in a basket and released backinto the lagoon. At about 12:30 it made its way downthrough a large natural channel (Grande Passe) out ofthe lagoon and was not seen again.A video recording of the seal was taken on the firstday and it was identified as a juvenile Subantarctic furseal Arctocephalus tropicalis by its small size, creamywhite face, throat and chest, and long vibrissae (Fig. 1).Its sex is unknown, but males are more common;Shaughnessy and Ross (1980) documented 16 of 22 A.tropicalis strandings in southern Africa as being males.Shortly after this event, two small seals were cap-tured on the island of Mauritius and kept at the AlbionFisheries Research Centre at Petite Rivière Noire inSouth-East Mauritius (20°30´S, 57°30´E; Fig. 2),where they were also identified as A. tropicalis. Thesmaller of the two, a male, was caught in late July 2001weighing 6.5 kg. It was transferred by air to the EastLondon Aquarium, South Africa, on 24 August 2001,where on 5 February 2003 it was in good health andweighed 26.5 kg. The larger (sex unknown) wascaught on 31 July 2001 weighing 10 kg. This animalhad a wound on its back and died in Mauritius on 16August 2001. It is doubtful whether the smaller animalwas the same one that hauled out in Rodrigues.This is another interesting record of vagrant Sub-antarctic fur seals in the tropics, far from their natalcolony. Other examples of extralimital tropical recordsinclude two adult males found on the coast of Angolaat 9°20´S (Carr et al. 1985) and an immature male andfemale on the coast of Brazil at 9°40´S and 12°54´Srespectively (Neves et al. 1990, Pinedo 1990). In theIndian Ocean, a juvenile was found at the Comores at12°30´S, 44°30´E (David et al. 1993), and a juvenileon the east coast of Madagascar at 22°08´S, 48°01´E(Garrigue and Ross 1996). The present record on Rod-rigues is the most easterly of these by some 1 800 km.The farthest east that this species has been recordedis on Macquarie Island (159°E; Shaughnessy et al.1988, Goldsworthy 1999) and the South Island of NewZealand (Csordas 1962). All the Indian Ocean sightingswere in the winter period of July and August, identifiedby Shaughnessy and Ross (1980) as the period of moststrandings in southern Africa (19 of 22 records werefrom May to September).The closest breeding colonies of A. tropicalis toRodrigues are on Amsterdam and St Paul islands, theIles Crozet and Marion and Prince Edward islands(Fig. 2). In theory, it might have come from any of404 African Journal of Marine Science 25 2003Amsterdam IslandMauritiusRodriguesCrozet IslandsPr. Edward IslandMarion IslandHeard IslandKerguelen IslandsRichard’s BaySaldanha BayCAPE TOWNComoresSt Paul Island15°30°45°20°25°35°40°50°55°S0° 15° 30° 45° 60° 75° 90° E10°5°15°Tristan da CunhaGough IslandBouvet IslandW××××× ××××SOUTHAFRICAMADAGASCARNAMIBIAANGOLAFig.2 Map showing the closest breeding sites (underlined) of A. tropicalis to Rodrigues Island and Mauritius,where the vagrant seals were found. The symbol × indicates sightings of vagrantsthese, but Amsterdam Island is the closest by a consid-erable margin, being about 2 500 km from Rodriguescompared with about 3 200 km from Iles Crozet andfarther from the others. Garrigue and Ross (1996)studied the Indian Ocean current systems and con-cluded that a seal from Amsterdam Island would bemore likely to reach Madagascar from the north thanfrom the south, by utilizing the northward flow of theSouth Indian Ocean Current and the westward flow ofthe South Equatorial Current. The same line of rea-soning could be used for a seal to reach Rodrigues orMauritius, making Amsterdam Island the most likelysource of these animals (Garrigue and Ross 1996).Seals from Marion Island can reach South Africa; afemale tagged as a pup at Marion Island was founddead at Saldanha Bay in September 1984, when almosttwo years of age (Bester 1989). In this context, it maybe relevant that the population of A. tropicalis hasbeen increasing in recent years and that there maytherefore be a greater likelihood of stray animals beingfound far from their natal colonies (Kerley 1987,Roux 1987, Hofmeyr et al. 1997).ACKNOWLEDGEMENTSThanks are due to Mr P. Haddow (Seal ConservationSociety, U.K.) for his valuable advice and to Mr F.Felicité (Fisheries Protection Services, Rodrigues) forhis Creole translation.LITERATURE CITEDBESTER, M. N. 1989 — Movements of southern elephant sealsand subantarctic fur seals in relation to Marion Island. Mar.Mamm. Sci. 5: 257–265.CARR, T., CARR, N. and J. H. M. DAVID 1985 — A record of thesub-Antarctic fur seal Arctocephalus tropicalis in Angola.S. Afr. J. Zool. 20: p. 77.CSORDAS, S. E. 1962 — The Kerguelen fur seal on MacquarieIsland. Vict. Nat. 79: 226–229.DAVID, J. H. M., MERCER, J. and K. HUNTER 1993 — A vagrantSubantarctic fur seal Arctocephalus tropicalis found in theComores. S. Afr. J. Zool. 28: 61–62.GARRIGUE, C. and G. J. B. ROSS 1996 — A record of the Sub-antarctic fur seal, Arctocephalus tropicalis, from Madagascar,Indian Ocean. Mar. Mamm. Sci. 12: 624–627.GOLDSWORTHY, S. D. 1999 — Maternal attendance behaviourof sympatrically breeding Antarctic and Subantarctic furseals, Arctocephalus spp., at Macquarie Island. Polar Biol.21: 316–325.HOFMEYR, G. J. G., BESTER, M. N. and F. C. JONKER 1997 —Changes in population sizes and distribution of fur seals atMarion Island. Polar Biol. 17: 150–158.KERLEY, G. I. H. 1987 — Arctocephalus tropicalis on the PrinceEdward Islands. In Status, Biology, and Ecology of FurSeals. Croxall, J. P. and R. L. Gentry (Eds). NOAA tech. Rep.NMFS 51: 61–64. (Proceedings of an International Sym-posium and Workshop, Cambridge, England, April 1984).NEVES, M. L. C., REIS, M. S. S. and M. T. R. BRASILEIRO1990 — Sobre a ocorrência de Arctocephalus tropicalis (Gray,1872) na Baia de Todos os Santos, Bahia, Brasil (Mammalia,Arctocephalinae). 4a Reunión de Trabajo de Especialistasen Mamíferos Acuáticos de América del Sur, November1990, Valdivia, Chile: p. 47.PINEDO, M. C. 1990 — Ocorrência de pinípedes na costa brasileira.Garcia de Orta, Séria Zoologia, Lisboa 15: 37–48.ROUX, J-P. 1987 — Subantarctic fur seal, Arctocephalus tropicalis,in French Subantarctic territories. In Status, Biology, andEcology of Fur Seals. Croxall, J. P. and R. L. Gentry (Eds). NOAAtech. Rep. NMFS 51: 79–81 (Proceedings of an InternationalSymposium and Workshop, Cambridge, England, April 1984).SHAUGHNESSY, P. D. and G. J. B. ROSS 1980 — Records ofthe Sub-antarctic fur seal (Arctocephalus tropicalis) fromSouth Africa with notes on its biology and some observationsof captive animals. Ann. S. Afr. Mus. 82(2): 71–89.SHAUGHNESSY, P. D., SHAUGHNESSY, G. L. and L. FLETCHER1988 — Recovery of the fur seal population at MacquarieIsland. Pap. Proc. R. Soc. Tasm. 122: 177–187.David & Salmon: Record of Subantarctic Fur Seal from Rodrigues and Mauritius2003 405

RECORDS OF THE SUBANTARCTIC FUR SEAL ARCTOCEPHALUS TROPICALIS FROM RODRIGUES AND MAURITIUS, INDIAN OCEAN

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RECORDS OF THE SUBANTARCTIC FUR SEAL ARCTOCEPHALUS TROPICALIS FROM RODRIGUES AND MAURITIUS, INDIAN OCEAN

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