A Case of Offspring Adoption in Free-Ranging Polar Bears (Ursus maritimus)

ABSTRACT. During a study of the reproductive ecology of polar bears (Ursus maritimus) in western Hudson Bay (Canada), we documented a case of litter adoption. In an eight-month period, a ten-year-old adult female lost a litter of two cubs-of-the-year and adopted three other cubs-of-the-year. This is...

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Bibliographic Details
Main Authors: S. N. Atkinson, M. R. L. Cattet, S. C. Polischuk, M. A. Ramsay
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 1995
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.571.9547
http://pubs.aina.ucalgary.ca/arctic/arctic49-1-94.pdf
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Summary:ABSTRACT. During a study of the reproductive ecology of polar bears (Ursus maritimus) in western Hudson Bay (Canada), we documented a case of litter adoption. In an eight-month period, a ten-year-old adult female lost a litter of two cubs-of-the-year and adopted three other cubs-of-the-year. This is the first reported case of natural offspring adoption in polar bears, and its significance as a reproductive strategy is unknown. Nevertheless, the observation raises questions regarding the social circumstances under which adoption may occur and the benefits or costs to maternal fitness in a solitary mammal such as the polar bear. Key words: polar bear, Ursus maritimus, litter adoption, maternal fitness RÉSUMÉ. Au cours d’une étude portant sur l’écologie de la reproduction des ours polaires (Ursus maritimus) dans la partie ouest de la baie d’Hudson (Canada), on a documenté un cas d’adoption de litière. Au cours d’une période de huit mois, une femelle adulte de dix ans a perdu sa litière de deux petits âgés de moins d’un an et adopté trois autres petits de l’année. Cet événement est le premier