Abstracts

Presented by Cynthia E. Anchor - Email: cynthia.anchor@sdstate.edu

Past research has provided evidence that movement patterns and habitat use by waterfowl shift as cover and foraging needs change across life history periods. During the post-fledging period, the behavior and physiology of young mallards (Anas platyrhynchos) are unique as they learn to fly and navigate, exploit new forage and wetland types, develop settling and social cues, molt, avoid predators, and prepare for migration. Despite the occurrence of these unique life history events, the movements and ecology of hatch year mallards during this time are essentially unstudied. However, the advent of small (< 35 g) transmitters integrated with GPS and cellular technologies has enabled us to investigate movements over larger spatial and temporal extents. We implanted 32g abdominal transmitters into hatch year mallards in North and South Dakota and collected one location every five hours for each individual from August through December 2018. The mean distance between locations across 47 individuals was 1.86 ± 0.05 (SE) km during the pre-migration period and 26.2 ± 2.6 km after migration began. The earliest observed migration by our marked birds was initiated on 3 October and the latest observed migration was initiated on 23 November. The relatively short and infrequent movements made by hatch year mallards during the post-fledging period, and the timing of migration relative to hunting seasons, likely contribute to the vulnerability of young birds to hunting pressure and may directly affect the recruitment of young mallards into next year’s breeding population.