Migration strategies of Black Oystercatchers (Haematopus bachmani) breeding in the Gulf of Alaska

Advances in tracking technology have documented an astonishing array of migratory movements and revealed that, in many species, individuals within a population can exhibit different migration strategies. Yet, the drivers responsible for variation in migration strategies remain poorly understood. In this thesis, I evaluate methods used to attach tracking devices to Black Oystercatchers (Haematopus bachmani), describe their migration, and test a suite of hypotheses for partial migration. I found that devices attached using a leg-loop harness had no detectable effect on whether individuals were resighted in subsequent years but that devices attached to leg bands significantly reduced resighting probability. I confirmed that Black Oystercatchers are partial migrants: some individuals remained resident in Alaska year-round while others migrated to British Columbia. I also found evidence that individual migration decisions were influenced by an individual's diet, providing support for the trophic polymorphism hypothesis for partial migration.