AnAge entry for Ursus maritimus

Lifespan, ageing, and relevant traits

Like in other species of bears, there is a delayed implantation of the fertilized eggs. That extends the pregnancy to 195-265 days [0434]. A wild born female kept in captivity at the Detroit Zoo was about 43.8 years of age when she died [0671].

Life history traits (averages)

Metabolism

References

[0671] Richard Weigl (2005), Longevity of Mammals in Captivity; from the Living Collections of the World
[0610] Ernest (2003), Life history characteristics of placental non-volant mammals
[0078] McOrist et al. (2002), Cerebral arteriosclerosis in an aged captive polar bear (Ursus maritimus), PubMed
[0077] Nakayama et al. (2001), Fractal analysis of senile plaque observed in various animal species, PubMed
[0434] Ronald Nowak (1999), Walker's Mammals of the World
[0076] Tekirian et al. (1996), Carboxy terminal of beta-amyloid deposits in aged human, canine, and polar bear brains, PubMed
[0079] Uchida et al. (1995), Senile plaques and other senile changes in the brain of an aged American black bear, PubMed
[0455] Virginia Hayssen et al. (1993), Asdell's Patterns of Mammalian Reproduction: A Compendium of Species-Specific Data
[0075] Selkoe et al. (1987), Conservation of brain amyloid proteins in aged mammals and humans with Alzheimer's disease, PubMed
[0680] Wootton (1987), The effects of body mass, phylogeny, habitat, and trophic level on mammalian age at first reproduction
[0731] Zullinger et al. (1984), Fitting sigmoid equations to mammalian growth curves

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