Palumbo Matthew D, Petrie Scott A, Schummer Michael, Rubin Benjamin D, Bonner Simon
Department of Biology The University of Western Ontario London Ontario Canada.
Long Point Waterfowl and Wetlands Research Program Port Rowan Ontario Canada.
Ecol Evol. 2019 Feb 6;9(4):1798-1808. doi: 10.1002/ece3.4864. eCollection 2019 Feb.
Animals select resources to maximize fitness but associated costs and benefits are spatially and temporally variable. Differences in wetland management influence resource availability for ducks and mortality risk from duck hunting. The local distribution of the Mallard () is affected by this resource heterogeneity and variable risk from hunting. Regional conservation strategies primarily focus on how waterfowl distributions are affected by food resources during the nonbreeding season. To test if Mallard resource selection was related to the abundance of resources, risks, or a combination, we studied resource selection of adult female Mallards during autumn and winter. We developed a digital spatial layer for Lake St. Clair, Ontario, Canada, that classified resources important to Mallards and assigned these resources a risk level based on ownership type and presumed disturbance from hunting. We monitored 59 individuals with GPS back-pack transmitters prior to, during, and after the hunting season and used discrete choice modeling to generate diurnal and nocturnal resource selection estimates. The model that classified available resources and presumed risk best explained Mallard resource selection strategies. Resource selection varied within and among seasons. Ducks selected for federal, state and private managed wetland complexes that provided an intermediate or relatively greater amount of refuge and foraging options than public hunting areas. Across all diel periods and seasons, there was selection for federally managed marshes and private supplemental feeding refuges that prohibited hunting. Mallard resource selection demonstrated trade-offs related to the management of mortality risk, anthropogenic disturbances, and foraging opportunities. Understanding how waterfowl respond to heterogeneous landscapes of resources and risks can inform regional conservation strategies related to waterfowl distribution during the nonbreeding season.
动物选择资源以实现适应性最大化，但相关的成本和收益在空间和时间上是可变的。湿地管理的差异会影响鸭子可获得的资源以及狩猎导致的死亡风险。绿头鸭（ ）的局部分布受这种资源异质性和狩猎可变风险的影响。区域保护策略主要关注非繁殖季节食物资源如何影响水禽分布。为了测试绿头鸭的资源选择是否与资源丰度、风险或两者的组合有关，我们研究了成年雌性绿头鸭在秋季和冬季的资源选择。我们为加拿大安大略省的圣克莱尔湖开发了一个数字空间层，对绿头鸭重要的资源进行分类，并根据所有权类型和推测的狩猎干扰为这些资源分配风险等级。我们在狩猎季节之前、期间和之后用GPS背包发射器监测了59只个体，并使用离散选择模型生成昼夜资源选择估计值。对可用资源和推测风险进行分类的模型最能解释绿头鸭的资源选择策略。资源选择在季节内和季节间有所不同。鸭子选择了联邦、州和私人管理的湿地复合体，这些湿地复合体比公共狩猎区提供了更多的避难所和觅食选择。在所有昼夜时段和季节中，鸭子都选择了禁止狩猎的联邦管理沼泽和私人补充喂食避难所。绿头鸭的资源选择表明了在死亡风险管理、人为干扰和觅食机会之间的权衡。了解水禽如何应对资源和风险的异质景观可以为非繁殖季节与水禽分布相关的区域保护策略提供信息。
