Abstracts

Presented by Justyn R. Foth - Email: justyn.foth@delaware.gov

Wood Ducks (Aix sponsa) select natural nesting cavities based on surrounding habitat types, cavity height, entrance dimensions, and other factors. If natural cavities are limiting, they readily use artificial nesting boxes. However, regional estimates of Wood Duck use of natural cavities and nest boxes is limited. Estimating Wood Duck use of boxes and identifying parameters that optimize use could have a considerable impact on efficiently managing a Wood Duck nest box program. Variable Wood Duck box monitoring efforts have been occurring in northern Delaware since 2004 on Delaware Wild Lands and Delaware Division of Fish & Wildlife properties. We monitored horizontal diameter of entrance (cm), orientation of entrance (degrees), height of entrance (cm), post placement (i.e., land or water), distance to the nearest box (m), distance to open water (m), average visual obstruction (cm), type of predator guard (sleeve vs. baffle), nest status (i.e., use, hatch or failure, and dump nesting), and tagged females and ducklings to estimate future recruitment. Using data from 20042017, we created a priori models using General Linear Modeling and Akaike Information Criteria to identify possible parameter effects on long term use of boxes and data from 20172019 on nest success. Nest box use has fluctuated between 2856% from 20042019, and in 2017 was positively correlated with increasing distance to neighboring box, distance to open water, and decreased visual obstruction. Nest success increased from 2017 (5.71%) to 2019 (70.83%). In 2019, tagging efforts began and we recaptured four previously banded females, deployed 45 new leg bands, and web-tagged 226 ducklings of either sex. These data along with ongoing Wood Duck monitoring by us and our partners (Nemours Wildlife Foundation, Clemson University, SC Department of Natural Resources, and Mississippi State University) may allow managers to select box locations to optimize Wood Duck production.