The Mating System and Life History of the Polar Bear

  • Author / Creator
    Richardson, Evan Shaun
  • Mating systems evolve in response to factors that influence the distribution and availability of mates. In turn mating systems can influence species life histories as a result of sexual selection. Most of what is known about sexual selection in large mammals comes from long-term studies of gregarious species and little information exists on the mating systems and opportunity for sexual selection in solitary carnivores. In this thesis I combine long-term mark-recapture and genetic data to describe the mating system and the opportunity for sexual selection in the western Hudson Bay polar bear (Ursus maritimus) population. Using genetically based parentage assignments I provide the first estimates of lifetime reproductive success in male and female polar bears. These data along with information on individual phenotypes are then used to explicitly test the hypothesis that male biased size dimorphism in polar bears is the result of sexual selection on male traits. I conclude my thesis by examining long-term trends in sea ice availability in western Hudson Bay and examine the potential influence of sea ice conditions during early development on polar bear growth. The overall objective of this thesis is to provide much needed insight into the mating system and life history of polar bears, to aid further investigations into the evolutionary ecology of the species.

  • Subjects / Keywords
  • Graduation date
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
    • Department of Biological Sciences
  • Specialization
    • Ecology
  • Supervisor / co-supervisor and their department(s)
    • Derocher, Andrew (Biological Sciences)
  • Examining committee members and their departments
    • Hik, David (Biological Sciences)
    • Stirling, Ian (Biological Sciences)
    • Boyce, Mark (Biological Sciences)
    • Ferguson, Steve (Zoology - University of Manitoba)