Gene flow within and between different regions of the
Southern Hudson Bay and James Bay Polar Bears.

The Committee on the Status of Species at Risk in Ontario (COSSARO) currently classify polar bears (Ursus maritimus) as a vulnerable species. In addition, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) classifies them as a species of special concern. Polar bears can live approximately 25 years and exhibit low reproductive rates. Traditionally, this species was thought to be a nomadic creature maintaining no visible home range. However, in more recent years, mark-recapture data has shown that they may be philopatric and thereby demonstrating seasonal fidelity to specific areas (i.e. denning sites for females). With this discovery it is essential to conserve all polar bear habitat.

There are currently 19 recognized populations of polar bears found throughout the world’s circumpolar region. Perhaps, the most important feature to the survival of polar bears is the Arctic landscape itself. Bears depend of the sea ice as a platform from which to hunt, breed and also as a vehicle on which to travel. During the winter months, polar bears are found out on the ice feeding to prepare for the summer season, at which time, the ice retreats forcing the bears ashore to den and give birth. At this time the males and non-pregnant females can fast for up to 4 months, while pregnant females fast for as long as 8 months.

The ice, which the polar bears inhabit, may be becoming threatened by global warming. The main
effect of this phenomenon is a change in the freeze-thaw patterns of ice, causing the bears to fast longer, in turn, decreasing reproductive rates. The effects of global warming will be most noticeable in the Hudson Bay regions of Manitoba and Ontario. This region currently contains the 3 most southerly populations of polar bears, the Foxe Basin, the Western Hudson Bay and the Southern Hudson Bay (including the James Bay). It is these 3 populations which are now becoming the focus of extensive ecological and genetic studies.

The Southern Hudson Bay population of polar bears has been the least extensively investigated. There are approximately 1,000 bears in this region some of which are now being examined through genetic analysis.

The Natural Resources DNA Profiling & Forensic Centre in conjunction with the Ontario Ministry of Natural Resources are investigating the levels of gene flow within and between bears from the southern Hudson Bay and James Bay areas. It is thought that
as freeze-thaw patterns of ice in the Hudson Bay change the polar bears in this region may also become isolated and therefore, demonstrate decreasing levels of gene flow. In the future, it is hoped that more samples will become available, from other bears in the region. This will make it possible to investigate levels of gene flow within the entire Hudson Bay including the Foxe Basin.

For more information, Please contact
Paul Wilson, or Brad White at the NRDPFC.

Natural Resources DNA Profiling and Forensic Centre DNA Building, Trent University, 2140 East Bank Drive, Peterborough, Ontario, Canada, K9J 7B8 Phone: (705) 748-1011 ext. 7126| Fax (705) 748-1132 Email: info@nrdpfc.ca