Optimal migration routes of Dusky Canada Geese: can they indicate estuaries in British Columbia for conservation?

• Main Author: Kereki, Christina Jane
• Format: Thesis
• Language: English
• Published: 2007
• Subjects: Canada; Pacific; British Columbia; Fraser River; Branta canadensis
• Online Access: http://summit.sfu.ca/item/2581

In response to increasing threats, habitat loss, and degradation of British Columbian (BC) estuaries, the Pacific Estuary Conservation Program (PECP) protects estuaries through land acquisition and stewardship programs. To assist the PECP in prioritizing BC estuaries, I develop a conservation tool that exclusively considers estuarine significance within a reserve network for migrating waterfowl. Using a dynamic state variable (DSV) optimization model, I predict estuary stopovers used by Dusky Canada Geese (Branta canadensis occidentalis) during spring migration. The DSV model predicts that only geese beginning migration in poor condition with respect to fat deposition use estuaries to maximize expected fitness. Numerous versions of the DSV model identify the Fraser River Estuary as an important stopover for geese of initially lower energy reserves. Introducing the assumption of density-dependence increases the total number of estuaries used as stopovers. Postulated scenarios of estuarine habitat losses decrease expected fitness more than scenarios of population increases.