Abstracts

Presented by J. Boomer Malanchuk - Email: bmalanchuk@ksu.edu

Mottled duck (Anas fulvigula) pairs use pair ponds from as early as February through mid-incubation. Mottled ducks defend pair ponds as territories because they provide access to resources and safety from predators. Pair ponds are important post-breeding because they provide most of invertebrate and other food items necessary for reproduction and recruitment. Little is known about the characteristics of ponds that attract paired mottled ducks for breeding efforts. It is important for managers to identify priority use areas on the broad scale of the Chenier Plain of Texas. We examined mottled duck pair pond use through the following objectives, 1) determine characteristics of pair ponds that attract breeding mottled ducks, 2) predict pair pond selection by mottled ducks based on salinity, depth, area, grazing regime, burning regime, emergent vegetation, submergent vegetation, and vegetation height, and 3) provide management options based on the results of analysis. We evaluated habitat selection using resource selection functions with Akaike Information Criterion model selection to understand the effects of 8 explanatory variables on probability of pair pond use by mottled ducks in a stratified survey of 822 ponds. Top-ranked models were assessed for model weight and significance of beta coefficient. The top-ranked single variable model was pair pond area, which predicted pair pond use decreases with increasing area. Additionally, we tested additive and interaction models between uncorrelated variables, with preliminary results indicating mottled duck pairs select for small ponds with submerged aquatic vegetation. The future of mottled duck conservation on the Chenier Plain will rely on conserving small pair ponds with submerged aquatic vegetation while managing for other habitat types that may be limiting (i.e., nesting cover, brooding sites, and molting areas).