During this time of year, Marion Island’s beaches are full of breeding Southern elephant seals (SES), Mirounga leonina, and this season’s pups are already starting to wean. SES pups are born at a weight of approximately 40 kg and grow up to anything between 100-200 kg within 3 weeks of suckling, where after they are weaned and left to fend for themselves. They usually laze away on the beaches for a little while after weaning before they take on the big ocean in search of a hearty meal. In the past it was thought that these juvenile SES feed almost exclusively on fish and squid, but South African scientist have found that crustaceans (presumably sub-Antarctic krill) form a much bigger part of their diet than previously thought. Using stable isotope analysis (carbon and nitrogen) of the whiskers, these scientists could reconstruct the diet of several juvenile SES from Marion Island. Read the full story at: http://doi.org/10.3354/meps12240
Ref: Lübcker N, Reisinger RR, Oosthuizen WC, de Bruyn PJN, van Tonder A, Pistorius PA, Bester MN (2017) Low trophic level diet of juvenile southern elephant seals Mirounga leonina from Marion Island: a stable isotope investigation using vibrissal regrowths. Mar Ecol Prog Ser 577:237-250.