Another leucistic elephant seal from the Southern Oceans

03/06/2009 10:04:31 Courtesy of Ryan Reisinger - Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, South Africa

We observed a light coloured female southern elephant seal juvenile (Mirounga leonina) twice at Marion
Island in August 2008 and confirmed that it was leucistic rather than albinistic. Though there have been a few previous reports of light-coloured southern elephant seals, this was thought to be the first confirmed case of leucism in this species (A Wildlife Extra reader has provided an image of another Leucistic Elephant seal taken in 2003 Ed.). Judged to be 1-2 years old, and because we have not observed any leucistic pups at Marion Island during the past 2 years despite an extensive monitoring and tagging program, we think that this animal was probably born at nearby Prince Edward Island or perhaps further afield at Îles Crozet.

We observed a light coloured southern elephant seal at Marion Island on 23 August 2008 at 13:30 GMT+3, at Whale Bird Beach (46°57_17_S, 37°52_3_E). The animal was resting next to a normally coloured elephant seal of similar size. The animals were photographed in the same frame for comparison and exposures were varied to prevent exaggerating the light individual's colour due to overexposure.

Skin biopsy
We observed the seal (a female) again on 30 August 2008 when we confirmed that it was leucistic after we
chemically immobilized it, tagged it and took a skin biopsy. Once the seal recovered from the anaesthetic, it moved down the beach and into the ocean. Its pelage was a uniformly creamy white colour, the exposed skin on the eyes and nose was the usual dark brown of the species, and the eyes were also normally coloured. The muzzle, eyebrows, and nails of the fore-flippers were also light coloured, in contrast to the species' usual dark colouring.

Leucsim
Leucism is characterized by reduced pigmentation, resulting in dark-eyed anomalously white animals, while albinism is an inherited condition which results in a total lack of pigmentation. Despite several decades of harvesting southern elephant seals at most colonies in the nineteenth and early twentieth centuries, and extensive long-term monitoring of many of them since, there were no historical records of light coloured elephant seals.

Acknowledgments We thank the South African Department of Environmental Affairs and Tourism for providing logistical support within the South African National Antarctic Programme, and the Department of Science and Technology administered through the National Research Foundation) for funding the pinniped monitoring programme at Marion Island.

First published Reisinger et al. 2009 Leucistic southern elephant seal at Marion Island. Polar Biology 32:509-511.