-48- 



3) Ross Seals 



Ross seals are also distributed circumpolarly , (rarely 

 north of 55° S.) and prefer consolidated pack ice dominated 

 by large floes. Some censuses suggest that Ross seals tend 

 to be distributed in local, high density patches throughout 

 the pack ice zone (King, 1964; Erickson et al., 1969; 1972; 

 Erickson, 1971) although Gilbert and Erickson (1977) did 

 not support this idea. 



4) Weddell Seals 



The preferred habitat of Weddell seals is fast ice. 

 Although primarily a circumpolar coastal inhabitant, Weddell 

 seals are occasionally found in pack ice and on the sub- 

 antarctic islands. 



Weddell seals use predictable pupping and breeding areas, 

 usually tide cracks as shown by Stirling (1969b, 1969c), 

 Siniff et al. (1976), and DeMaster (1978). In pack ice, 

 Weddell seals did not exhibit observable pack ice type pref- 

 erences (Gilbert and Ericsson, 1977) . 



b. Movements and Annual Cycle 



Movements of the four true Antarctic seals are not well 

 known. Although it has not been specifically demonstrated, 

 it seems likely that individuals in pack ice move with the 

 pack ice during its general north-south seasonal fluctuation. 

 Figure 17 illustrates six presumed residual pack ice areas 

 which may serve as refugia during the Antarctic summer. 



1) Crabeater Seals 



Bertram (1940), Turbott (1952, Bonner and Laws (1964), 

 and Solyanik (1964) have, among others, provided evidence of 

 a southward movement of subadult crabeater seals during the 

 summer. The seals then move northward as water freezes and 

 suitable pack ice near the advancing edge only becomes avail- 

 able to the north. Crabeater seals pup during September and 

 October in the pack ice (0ritsland, 1970b; Siniff and Reichle, 

 1976; Siniff et al., 1977b; Siniff et al., 1978). Following 

 weaning, pups apparently congregate in pack ice areas and in 

 fast ice bays while adults breed on the pack ice (Siniff et al, 

 1977b) . Other authors have suggested that weaned pups 

 congregate at areas of very dense pack ice near land (Lindsey, 

 1937; Bertram, 1940; Hofman, 1975). Presumably, most young 

 individuals remain in these groups until they become 

 reproductively active. Age of first reproduction appears to 

 be between 2.5 and 6 years of age (Laws, 1958; 0ritsland, 

 1970a; Siniff et al., unpublished data), and life span over 

 20 years (Laws, 1958; 0ritsland, 1970b). 



