H-22 



RESEARCH PROGRAMMES 



diet and takes penguins under rather specific conditions but utilizes kriU, fish and other seals, 

 particularly young Crabeater Seals, when conditions are favourable. 



Little is known about the life cycle of the Leopard Seal. Pupping and mating probably 

 occur in the pack ice. Oritsland (1970) reported that males and females become sexually 

 mature between three and six years with the maximum hfe span in the vicinity of 25 years. 



(c) Ross Seal. 



Information on the Ross Seal, known as the rarest and least studied of the Antarctic seals, 

 has been summarized by Hofman and others (1973). It appears mainly to inhabit pack ice of 

 5/10-7/10 cover. Most sightings have been of solitary individuals but groups of up to 13 have 

 been sighted (Laws, 1964). The Ross Seal is extremely rare in the Weddell Sea but its 

 distribution is uneven: much higher concentrations are found in the Amundsen, Bellingshausen 

 and King Haakon VII seas. It is considered to account for between one and two per cent of the 

 total Antarctic pinniped population. 



Cephalopods have been reported to be the main food of the Ross Seal although both fish 

 and krill have been found in its stomachs. Information on reproduction is limited, most coming 

 from Oritsland (1970) who examined 15 specimens. It appears that pupping and mating occur 

 in November and December. 



(d) Weddell Seal. 



The Weddell Seal is the best known of the Antarctic seal species as it is found near 

 Antarctic shore stations where access for study has been possible. It aggregates during the 

 pupping season along perennial tide cracks where pups are born on the surface of the ice. 

 Pupping occurs as early as September in northern areas and in late October and early November 

 in the more southern areas. Weaning is usually accomplished by the sixth or seventh week, at 

 which time the colony disperses. 



The males occupy underwater territories (D. B. Siniff, unpublished ms) along the tide 

 crack; the exact time of mating is uncertain but it appears to be near weaning. As with the 

 other Antarctic seals, peak haul out is around local apparent noon. Their food includes fish, 

 crustaceans (including euphausiids), and cephalopods (Dearborn, 1965). At McMurdo Station 

 the Weddell Seal feeds on fish of the genus Trematomus and midwater species such as 

 Pleuragramma antarcticum. 



(e) Fur Seals. 



Although formerly hunted to near extinction, there is at present no harvest of these species 

 and the populations are increasing. 



The Fur Seal that breeds on islands south of the Antarctic Convergence is Arctocephalus 

 gazella (Repenning and others, 1971). The main population oi A. gazella is found on South 

 Georgia. It has increased from at most a few hundred in the 1930's to around 350 000 now. 

 Subsidiary smaller populations are found on other islands of the Scotia Arc north of 65°S, 

 Bouvet and McDonald islands and, lately, this species has also begun breeding at Marion Island, 

 sympatrically with the more northern form>4. tropicalis (Bonner, 1968; Erickson and Hofman, 

 1974). The species may be expected to reach its former abundance, measured in millions, in 

 15—20 years time. 



A. tropicalis, the Fur Seal of the islands to the north of the Antarctic Convergence, has 

 shown a slower rate of recovery. Stocks at Marion Island have increased from around 500 to 

 7 000 between 1950 and the present, and at Gough Island from about 1 2 000 to 26 000 in the 

 same period (P. R. Condy, personal communication). 



Fur Seals come ashore to breed on rocky coasts in November and lactating females remain 

 in the vicinity of the rookeries until the following March. For A. gazella food at this period 

 appears to be mainly Euphausia superba (though fishes and squids are also taken). The food of 

 A. tropicalis is less well known but includes fishes, squids or the rock lobster Jasus sp. After 



