Duckling survival, fecundity, and habitat selection of mottled duck broods on the upper Texas Gulf Coast

Mottled ducks (Anas fulvigula) on the western Gulf Coast have exhibited a steep population decline since the mid 1990s. Low rates of breeding incidence and nest success have been implicated in this decline, but duckling survival and the habitat needs of broods have not been previously investigated in this region. We fitted mottled duck ducklings and adult females with radio transmitters and tracked broods to estimate duckling survival and brood habitat selection on the upper Texas Gulf Coast. Duckling survival to 30 days was high (range among models 0.354–0.567) compared to other dabbling duck species. Estimated fecundity was low, (range among models 0.398–0.634) however, indicating that overall reproductive output is low. Within coastal marsh, broods selected home ranges with more water cover and less upland and fresh marsh landcover than was available in the study area. Within coastal marsh home ranges, broods selected for water cover relative to other landcover types, and there was some evidence that broods avoided unvegetated landcover. Although high quality brood habitat is undeniably important, management efforts to increase mottled duck population growth on the western Gulf Coast may best be spent on increasing nesting habitat quality to increase nest success and breeding incidence.