Weddell Seal (Leptonychotes weddellii)
The Weddell Seal (Leptonychotes weddellii) is a seal with a circumpolar of Antarctica, discovered and named by an explorer of the same name on an expedition to the Southern Ocean. They are a widespread and seemingly abundant species, thus classified as Least Concern by the IUCN. Estimated population size = 700,000.
L. weddellii are true seals, of a fairly large size (males ♂ up to 3 m long/ 580 kg, females ♀ up to 3.3 m/ 600 kg), with relatively short fore and hind flippers, the rear which face backwards.The seals are plump and chunky with a round head that also seems rather small in comparison. Their faces are compact, with upturned muzzle and large, dark eyes. L. weddellii can range in colour from a bluish back or dark silvery grey, through to more brown or buff, and they have obvious spotting or blotching of a lighter colour all over.
L. weddelli are generalist predators who feed predominantly during the day. Large components of their diet are benthic, demersal and pelagic icefish, toothfish, lanternfish, cephalopods, and crustaceans. However, this will vary amongst populations as they take advantage of what is available locally. They can dive up to 600 m and forage underwater for up to an hour and a half.
Sexual maturity – males ♂ 4-8 years old/ females ♀ 3-6 years old.
Breeding L. weddellii have a polygynous structure, and form loose colonies on ice or land from September through to November, depending upon location. Mating occurs in water and after a period of delayed implantation, gestation takes place over 11 months. The pups are born with a soft grey lanugo coat to keep warm in the cold, and will not enter the water until about 2 weeks of age. During this initial period, the mother will fast, but once the pup is more mobile, she will start to undertake foraging trips. The pup morphs into its juvenile pelage by around 6 weeks. Shortly afterwards, at just shy of 2 months, the youngsters are weaned. Now they will hunt independently, though may remain locally for some time. The adults will moult annually in December-March when the weather is warmest. L. weddellii can expect to live up to about 30 years old.
The different populations of L. weddellii are not separated into different subspecies.
Photos: (1) Antje Kakuschke, (2) Amanda Warlick, (3) Emma Weitzner