Abstracts

Presented by Ray T. Alisauskas - Email: ray.alisauskas@canada.ca

Banding waterfowl, in combination with the citizen science provided by hunters that report marks from harvested birds, is a long-standing, institutionalized practice for estimating probabilities of survival and exploitation, i.e., harvest from such populations. However, estimation of range-wide population abundance is also possible from these data when combined with total population harvest. Waterfowl marking with uniquely identifiable bands done during late summer in North America is often referred to as preseason banding. Mass capture of arctic geese for preseason banding is normally done in July (nonbreeders) or August (failed breeders and breeders with young) during flightless molt of respective groups. An important assumption for proper inference about harvest rate provided from such samples of birds is that there is no mortality, natural or otherwise, during the interval between when birds are marked and the time that hunting seasons begin. Using simulation pertinent to midcontinent snow goose biology, we evaluated the effect of variable mortality that could occur between marking in the arctic and subsequent hunting seasons in Prairie Canada on estimates of survival and recovery probability of both juvenile and adult geese. There was no effect on survival probability during the interval between annual banding in subsequent years, but recovery probability and thus harvest probability was directly and inversely related to pre-harvest mortality of juvenile geese. We discuss the implications for inference about population abundance of midcontinent snow geese and other waterfowl drawn from Lincolns estimator.