AnAge entry for Ursus maritimus
Classification (HAGRID: 02253)
- Taxonomy
-
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia (Taxon entry)
Order: Carnivora
Family: Ursidae
Genus: Ursus
- Species
- Ursus maritimus
- Common name
- Polar bear
- Synonyms
- Ursus maritimus maritimus, Ursus maritimus marinus, Thalassarctos jenaensis, Thalassarctos eogroenlandicus, Thalassarctos labradorensis, Ursus polaris, Ursus marinus, Thalassarctos maritimus groenlandicus
Lifespan, ageing, and relevant traits
- Maximum longevity
- 43.8 years (captivity)
- Source
- ref. 671
- Sample size
- Medium
- Data quality
- Acceptable
- Observations
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]. An aged specimen had senile plaques [0955].
Life history traits (averages)
- Female sexual maturity
- 1,734 days
- Male sexual maturity
- 1,734 days
- Gestation
- 65 days
- Weaning
- 303 days
- Litter size
- 2 (viviparous)
- Litters per year
- 0.4
- Inter-litter interval
- 750 days
- Weight at birth
- 665 g
- Weight at weaning
- 27,000 g
- Adult weight
- 475,000 g
- Postnatal growth rate
- 0.0022 days-1 (from Gompertz function)
- Maximum longevity residual
- 121%
Metabolism
- Typical body temperature
- 310ºK or 36.8ºC or 98.2ºF
- Basal metabolic rate
- Not yet available
References
- [1143] Nussey et al. (2013), Senescence in natural populations of animals: widespread evidence and its implications for bio-gerontology (PubMed)
- [1136] Gomes et al. (2011), Comparative biology of mammalian telomeres: hypotheses on ancestral states and the roles of telomeres in longevity determination (PubMed)
- [0978] Jones et al. (2009), PanTHERIA: a species-level database of life history, ecology, and geography of extant and recently extinct mammals
- [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
- [1054] Hurst et al. (1991), Metabolic compensation in oil-exposed polar bears
- [0955] Cork et al. (1988), Neurofibrillary tangles and senile plaques in aged bears (PubMed)
- [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
External Resources
- Integrated Taxonomic Information System
- ITIS 180542
- Animal Diversity Web
- ADW account
- Encyclopaedia of Life
- Search EOL
- NCBI Taxonomy
- Taxonomy ID 29073
- Entrez
- Search all databases
- Ageing Literature
- Search Google Scholar or Search PubMed
- Images
- Google Image search
- Internet
- Search Google