Abstracts

Presented by Gary Macy - Email: gjmacy@syr.edu

The Anas rubripes (hereon black duck) population decreased by 50% since the 1950s and is a focal species of the U.S. Fish and Wildlife Service. Anas platyrhynchos (hereon mallards) have since replaced black ducks across much of their range in eastern North America. Black ducks and mallards are sympatric during breeding season in the Adirondack Park (AP), but also appear to segregate their habitat use between beaver-modified wetlands and human influenced areas, respectively. This segregation may favor mallards because wetland productivity is often greater in human influenced lakes relative to beaver-modified wetlands. Although studies of competitive exclusion between these ducks provide varying results, two species cant occupy the same niche indefinitely. We aim to test for differences in occupancy between black ducks and mallards in beaver-modified wetlands and human influenced lakes. Multi-species occupancy modeling is useful in generating estimates of occupancy for rare species (e.g., black ducks) that co-occur with more common species (e.g., mallards). We adapted a multi-species occupancy model in a Bayesian statistical framework that uses a time to detection function for detection probability. We will apply this analysis method to waterfowl surveys of beaver-modified wetlands and lakes in the AP. We will report preliminary results from surveys through early August 2019.