Population size and age determination in the Antarctic Fur seal Arctocephalus gazella

摘要: The population of Antarctic Fur seals Arctocephalus gazella at South Georgia is increasing rapidly and therefore great interest. Investigations the depend on two main techniques. (1) Population assessment, because size now too large for direct counts to be completely reliable, serious underestimates are appearing in areas high density. Aerial photography was used but needs further refinement before it becomes a consistently useful technique. Marking all pups sample beaches largely unsuccessful moved from beach they could marked. A mark–recapture method finally adopted indicated that numbers present may up 54% higher than actually counted. (2) process age determination tooth characters, which more difficult other pinnipeds. preparation interpretation teeth breeding cows described, based eleven specimens known age. most accurate results obtained whole 6, thereafter cement dentine layers thin sections must used. It concluded while young animals aged quite accurately, there probably tendency underestimate 9 years.