Genetic status of the Brown bear Vrsus arctos in Nordic zoos

Abstract

The continuing decline of Brown bears Ursus arctos in the wild and the recent discovery of genetic divergence among some wild populations has highlighted the need for a co‐ordinated captive‐breeding programme. This paper discusses some of the effects of extensive inbreeding of Brown bears in Nordic Zoos and examines the degree of genetic variability retained in the present population after a long period of genetically unmanaged breeding. The extent to which the geographic origin of the contributing founders is known is also examined and recommendations are made for future breeding management.

Conservation Genetics of Nordic Carnivores: Lessons from Zoos

“…Litter size decreases with 6.3% with 109'0 increase of Longevity decreases with increased level of inbreeding. LAIKRE and RYMAN 1991;LAIKRE et al 1993;ANDREN et al 1997;LUNDSTROM 1998, LAIKRE et al, in prep.…”

Hereditary defects and conservation genetic management of captive populations

“…C does include three albino bears, but there are some uncertainties regarding the ancestry of those animals. There is probably a link between C and B [Andrén et al, 1997], but due to incomplete studbook records in one particular zoo, it has not been possible to confirm this putative relationship. Therefore I have chosen to exclude the C pedigree from the present analysis.…”

“…1 [Andrén et al, 1997]). The present analysis is confined to the B component only and refers to the population that existed on December 31, 1993.…”

“…This new ambition includes avoiding propagation of individuals of unknown or mixed geographic origin, and addressing the problem of albinism. We previously examined the genetic status of this bear population, concluding that more than 80% of the animals carry alleles from founders with unknown geographic origin [Andrén et al, 1997]. Inbreeding depression expressed as a decrease in litter size has also been documented in this population .…”

“…The albino allele was introduced by F 15 or F 16 . (Modified from Andrén et al, 1997). Albino cubs had been produced by four breeding pairs in December 1993, and a fifth pair had albino offspring 1 year later.…”