AnAge entry for Ursus maritimus

Classification (HAGRID: 02704)

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

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

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 or Search Scirus
Images
Google Image search
Internet
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