Abstracts

Presented by Kali Rush - Email: krush@ducks.org

Although breeding ecology of wood ducks is well-studied, most research has involved captured birds from artificial nest boxes, where females and their offspring might be protected from predation. While this capture method is relatively easy and efficient, it inherently eliminates or reduces the probability of studying wood ducks that select natural tree cavities for nest sites. In addition to breeding parameters, most habitat selection studies on wood ducks have focused on individuals with confirmed nests. We captured female wood ducks prior to nest initiation, in decoy traps, and from artificial nest boxes, attached VHF transmitters to individuals, and tracked their location throughout the breeding season at Mead Wildlife Management Area (WMA) in central Wisconsin. Our sample of female wood ducks represented box-nesting (n=16), cavity-nesting (n=8), non-nesting (n=5) ducks, and those that we could not determine nests (n=14). We pooled data across years and estimated breeding season female survival at 0.343 (95% CI=0.192-0.613), and this did not vary by mass, trap type, nest attempt, or nest type. This survival estimate was the lowest published breeding season survival estimate we could find, indicating that Mead WMA might be a sink for wood duck populations, but additional years of monitoring would determine if female survival is consistently low at Mead WMA or if our estimates were a function of random environmental stochasticity. Breeding propensity was 0.44 for females captured pre-nesting but could be as high as 0.72 if unknown status wood ducks indeed initiated a nest. Not surprisingly, our sample of wood ducks selected for forested and scrub-shrub wetlands, but surprisingly, they also selected for five additional habitats, including those with less structural cover, suggesting managers should maintain diverse wetland complexes. Additional research that addresses survival and recruitment, especially for cavity-nesting individuals will serve to better understand and manage this species in Wisconsin.