Dabbling Duckling Habitat Use and Movements

We conducted a multi-year study (2016-2019) to identify elements of wetland habitat management that could potentially benefit breeding ducks. Specifically, we examined the influence of habitat variables in explaining habitat selection of managed wetlands near upland nesting sites by radio-tagged Mallard (Anas platyrhynchos) and Gadwall (Mareca strepera) ducklings in a brackish marsh (Suisun Marsh, California, USA). Each duckling location was associated with a unique wetland identification (after moving from their nest in upland habitats to a nearby wetland) and the corresponding wetland attributes for that year and the timing within the year (wetland type, dominant wetland vegetation, the percent of the wetland that contained vegetation cover, surface water salinity concentration, and flooded wetland area). For the habitat selection analysis, we also generated available locations in flooded wetlands on the landscape for each radio-tagged brood and associated the corresponding wetland attributes to those available locations. Additionally, we used daily locations of radio-tagged ducklings to quantify the number of wetlands used by ducklings, the frequency of inter-wetland movements, and duckling dispersal from the nest relative to species, age, and year.