Abstracts

Presented by Samantha Fino - Email: samantha.fino@sdstate.edu

Depredation is a major cause of nest failure. Understanding the predator community composition and predator movements, influenced by patch dynamics, is critical to explain predator-prey interactions, spatiotemporal habitat use, and foraging of nest predators. Similarly, it is important to understand how grassland patch dynamics indirectly influence nest survival of ducks, with predator behavior as the primary mechanism. Our study was conducted in Faulk and Hand counties, South Dakota, with the primary difference of one county being subject to coyote removal management for several years, and the other has not. Our main objective is to quantify the influence of patch dynamics on predator community composition, occupancy and use, and determine how that relates to duck nest survival. Prior to the nesting season, we radio marked raccoons, striped skunks, and coyotes (20 of each). Radio collars were programed to record a GPS point every 30 minutes from sunset to sunrise. Average home range size was 6.4 ± 1.5 km2 for raccoons and 9.4 ± 2.1 km2 for striped skunks, with a large portion of their GPS points overlapping developed areas and habitat edges. We nest searched 57 km2 and monitored 110 nests. Nest survival was significantly greater in Hand County, with weekly and seasonal survival at 78% and 37% respectively, than in Faulk County, with weekly and seasonal survival was 59% and 12% respectively (p-value = 0.002). Additionally, we conducted opportunistic raptor surveys, live trapping of small mammals, and predator surveys using camera traps to produce indices of abundance as covariates. We are currently using these data to explain variation in predator abundance, distribution and space use with respect to vegetation, patch and landscape characteristics as the mechanism behind nest survival. Results of this study will better assist state and federal agencies in developing recommendations that encourage upland game bird nest success.