Lifetime survival rates and senescence in northern elephant seals

The aim of this study was to extend 40 yr of prior demographic work on northern elephant seals (Mirounga angustirostris) at Año Nuevo, California, by including the oldest animals. We used a Bayesian mark-recapture analysis to estimate lifelong survival and lifespan of a cohort of 372 weaned pups bra...

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Bibliographic Details
Published in:Marine Mammal Science
Main Authors: Condit, Richard S., Reiter, Joanne, Morris, Patricia A., Berger, Ryan, Allen, Sarah G., Le Boeuf, Burney J.
Format: Article in Journal/Newspaper
Language:unknown
Published: 2014
Subjects:
Online Access:http://hdl.handle.net/10088/24575
https://doi.org/10.1111/mms.12025
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Summary:The aim of this study was to extend 40 yr of prior demographic work on northern elephant seals (Mirounga angustirostris) at Año Nuevo, California, by including the oldest animals. We used a Bayesian mark-recapture analysis to estimate lifelong survival and lifespan of a cohort of 372 weaned pups branded in 1985 1987 and resighted until 2008. Annual survival probability of females averaged 86.3%/yr at ages 5 16, then declined until age 21, the age of the oldest female. Male survival was lower, averaging 67.7%/yr from age 1 to age 15, the age of the oldest male. Northern elephant seal females in the expanding population at Año Nuevo live longer than southern elephant seal females (M. leonina) at colonies whose populations are declining. This comparison suggests that high survival of females is a key factor in population growth. STRI Peer-reviewed