Abstracts

Presented by Joseph D. Lancaster - Email: lancastj@illinois.edu

Recreational hunting harvest is a predatory force demonstrated to impart fear in surviving individuals. Survivors of near-predatory events may alter behavior and space use to avoid risky environments and events that could pose fitness costs via reduced energy income, survival, and breeding opportunities. We hypothesized that duck hunting and associated disturbances create a landscape of fear that shapes diel habitat use by mallards (Anas platyrhynchos) during winter in Mississippi. Specifically, we proposed that open habitats, such as flooded croplands and emergent wetlands, present increased anthropogenic predation risk over forested wetlands which provided greater physical isolation. We expected greater use of forested wetlands diurnally and flooded croplands and emergent wetlands nocturnally within hunting seasons, but diurnal use of flooded cropland and emergent wetlands would increase post-hunting season. We evaluated diel habitat use within and post-hunting seasons using 9,229 locations from 241 radiomarked female mallards during winters 2010-2012 and 2013-2015 in Mississippis Alluvial Valley. Supporting our prediction, mallards used forested wetlands 135% (77 211 [95% CI]) more diurnally than nocturnally within hunting seasons. However, flooded cropland and emergent wetlands were used 2% (23 35) and 53% (14 109) more diurnally than nocturnally within hunting seasons, respectively. Diurnal use of flooded cropland was 40% (14 71) greater following closure of hunting seasons, whereas emergent wetlands were used 8% (13 33) more during the hunting season. Mallards used complexes of flooded croplands and wetlands, but anthropogenic disturbance likely was confounded with other influences such as wetland management on inviolate sanctuaries, which may have influenced diel habitat use in the surrounding landscape. Restoration of forested wetlands at seasonally flooded elevations will provide long-term benefits to mallards in the region.