Freshwater impoundments surrounding Great Salt Lake are an important nesting habitat for several water birds, including duck species that nest along the dikes which create the impoundments. Great Salt Lake nesting sites are of particular importance to Cinnamon Teal, as they are in the heart of this species’ nesting range. After the flood in 1983, waterfowl production declined as a result of habitat loss. The habitat subsequently recovered, but predators previously not present (i.e., raccoons and red foxes) became established at the same time. High densities of predators now suppress the success of nesting waterfowl. To assess this problem, I located duck nests along dikes bordering freshwater impoundments by chain dragging. Nests were monitored throughout incubation, and nest predators were identified using game cameras. Following nest completion, nests sites were surveyed to assess whether ducks had selected nest sites with concealment from visual and/or olfactory predators.
Results/Conclusions
I located a total of 467 nests, including 270 Cinnamon Teal nests, 91 Mallard nests, and 106 Gadwall nests. Based on the apparent method, 45% of nests were successful, 49% depredated, and 6% abandoned. Nest predators were predominantly skunks and raccoons. During 2019, duck nest counts were the highest recorded by my lab during the last 15 years. Around some impoundments, abundance of duck nests appeared to swamp predators, and success rates were high in these areas. I believe that ducks seeking nest sites responded to plush vegetation during 2019, which, in turn, resulted from abundant snowfall and favorable precipitation in the spring.