The fight for forage : distribution and abundance patterns of Aleutian cackling Geese during spring staging

Thesis (M.S.)--Humboldt State University, Natural Resources: Wildlife, 2010The recovered population of Aleutian cackling goose (Branta hutchinsii leucopareia) uses pastures of Humboldt and Del Norte Counties in spring prior to the final migration to breeding grounds in Alaska. The availability of energetically profitable foraging sites is critical for geese to meet body condition thresholds that ultimately regulate survival and reproduction in the population. However, selection of these profitable foraging sites puts geese in conflict with livestock agriculture and this has lead to increased hazing and hunting activities. Patterns of Aleutian goose field use were observed and related to characteristics of fields including farm type, spatial location, and disturbance. I found that a spatial discrepancy exists on the spring landscape; geese selected fields closer to roosts and tidal sloughs, further from roads and structures, which were larger in area, with a greater surface area of water. Additionally, a temporal discrepancy exits throughout spring staging; distribution and abundance patterns of geese on foraging fields are dynamic and best predicted by shifting relationships of farm type, spatial characteristics, and disturbance at different periods throughout spring. Increased disturbance on the landscape has caused notable shifts in distribution and use of available fields. By identifying habitat features of fields that attract the most geese we can better approach a description of the birds??? requirements leading to designing suitable ???goose friendly??? habitats and reducing the burden on individual farmers