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Split Parturition Observed in a Captive North American Brown Bear ( Ursus arctos )
Author(s) -
Ware Jasmine V.,
Nelson O. Lynne,
Robbins Charles T.,
Jansen Heiko T.
Publication year - 2011
Publication title -
zoo biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.5
H-Index - 54
eISSN - 1098-2361
pISSN - 0733-3188
DOI - 10.1002/zoo.20424
Subject(s) - ursus , hibernation (computing) , biology , litter , mating , zoology , reproductive physiology , reproduction , pregnancy , adult male , physiology , ecology , endocrinology , demography , population , state (computer science) , genetics , algorithm , sociology , computer science
Reproductive physiology in North American ursids is characterized by mating from spring to early summer, delayed implantation, and birth during hibernation. During spring 2008, a captive adult female brown bear was mated with two adult males. Pregnancy was determined by elevated progesterone concentrations during late fall before hibernation. Two male cubs were born on December 31, 2008, and a third female cub was born 17 days later on January 16. All were successfully raised and all were confirmed to have identical paternity. When normalized to age, cub growth rates did not differ. To our knowledge, this is the first documented case of markedly different birth dates in a single litter of brown bear cubs. Zoo Biol 31: 255–259, 2012. © 2011 Wiley Periodicals, Inc.