SEAFWA 2018

AUTHORS: Tori Mezebish, Mark McConnell – University of Georgia Warnell School of Forestry and Natural Resources

ABSTRACT: Ring-necked ducks (Aythya collaris) are one of the most abundant and harvested North American diving ducks; however, few studies have investigated their overwintering movement. Overwintering movement ecology in relation to hunting disturbance and resource abundance could have implications for harvest regulations and wetland management. We quantified changes in daily movement distances of ring-necked ducks in the southern Atlantic Flyway during the 2017-2018 overwintering period. We calculated average daily step lengths for eleven satellite transmitter implanted females using hidden Markov modeling. Daily distance moved throughout the total overwintering period was 5.04 km, CI=4.31-5.77. Daily distance moved was significantly greater during (6.03 km, CI=5.12-6.9) than after hunting season (3.61 km, CI=2.68-4.55). Hunting events may have generated regular escape movements, resulting in greater daily step length during the hunting season. Decreased daily distance moved post-hunting season may have also corresponded to habitat availability changes. Many land managers drain wetlands shortly after waterfowl hunting ends, reducing regional wetland density. If resources at remaining wetlands were abundant enough to prevent extensive resource-seeking behavior, ring-neck movements may have corresponded to shorter distances between limited available wetlands. Moreover, this trend may not be a function of anthropogenic activity, but of migratory preparation. Hens likely decreased the magnitude of exploratory movements post-hunting season to energetically prepare for migration, and utilized minimal wetlands. Our findings demonstrate a behavioral shift in ring-neck movement ecology that may relate to hunting disturbance and resource distribution. Further research should investigate the impacts of each factor to better understand overwintering ring-necked duck ecology.