AnAge entry for Ursus americanus

Classification (HAGRID: 02702)

Taxonomy
Kingdom: Animalia
    Phylum: Chordata
        Class: Mammalia (Taxon entry)
            Order: Carnivora
                Family: Ursidae
                    Genus: Ursus
Species
Ursus americanus
Common name
American black bear

Lifespan, ageing, and relevant traits

Maximum longevity
34 years (captivity)
Source
ref. 671
Sample size
Large
Data quality
Acceptable
Observations

During hibernation body temperature floats around 32.5 degrees C. Although pregnancy in bears lasts for about 220 days, there is a delayed implantation and embryonic development only occurs in the last 10 weeks of pregnancy [0434]. In the wild, it has been suggested that they may live over 33 years [0558], which is dubious. Record longevity in captivity belongs to a wild born female that was about 34 years when she died in captivity [0671].

Life history traits (averages)

Female sexual maturity
1,278 days
Male sexual maturity
1,278 days
Gestation
70 days
Weaning
198 days
Litter size
2 (viviparous)
Litters per year
0.4
Inter-litter interval
730 days
Weight at birth
277.5 g
Weight at weaning
14,050 g
Adult weight
154,250 g
Postnatal growth rate
0.0029 days-1 (from Gompertz function)
Maximum longevity residual
111%

Metabolism

No information on metabolism is available.

References

External Resources

Integrated Taxonomic Information System
ITIS 180544
Animal Diversity Web
ADW account
Encyclopaedia of Life
Search EOL
NCBI Taxonomy
Taxonomy ID 9643
Entrez
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Ageing Literature
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Internet
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