<p>There is little known about lifespan in southern elephant seals. This is largely due to the lack of substantial information concerning the periods of the year when they are at sea. Average life expectancy in the wild, as seen during the breeding season, is about 23 years. However, about 30% of pups die in their first year. Captive <span class="taxon"><em>M. leonina</em></span> have lived to 15 years of age. Not much is known concerning the deaths of these mammals but, in addition to predation, weather and disease may play a large role in limiting their lifespan.<span> ("Elephant Seals", 1983; "Southern Elephant Seal", 2003; Anderson, 2003; Seal Conservation Society, 2001)</span></p>