Response of breeding duck pairs to predator reduction in North Dakota

Abstract

Predator management regularly improves waterfowl nesting success, often beyond levels believed necessary for population maintenance. If recruitment, survival of breeding females, and/or breeding site fidelity is increased on predator-reduced sites, then local breeding populations may increase in subsequent years. During 2005–2008, we annually conducted breeding pair surveys on >600 wetlands at 6 township-sized (93.2 km²) trapped sites and 4 non-trapped sites for the 5 most common upland nesting ducks in eastern North Dakota, USA. For each species, we developed a series of competing regression models that related breeding pair abundance to wetland size, predator management, and upland habitats adjacent to sampled wetlands. In contrast to previous studies, we found limited and equivocal evidence that breeding populations increased following predator management. We discuss multiple potential explanations for this lack of effect and suggest that managers should not assume that increased production as a product of elevated nest success will be compounded over years. © The Wildlife Society, 2013