Data from: Movement patterns of a keystone waterbird species are highly predictable from landscape configuration

Background: Movement behaviour is fundamental to the ecology of animals and their interactions with other organisms, and as such contributes to ecosystem dynamics. Waterfowl are key players in ecological processes in wetlands and surrounding habitats through predator-prey interactions and their transportation of nutrients and other organisms. Understanding the drivers of their movement behaviour is crucial to predict how environmental changes affect their role in ecosystem functioning. Mallards (Anas platyrhynchos) are the most abundant duck species worldwide and important dispersers of aquatic invertebrates, plants and pathogens like avian influenza viruses. By GPS tracking of 97 mallards in four landscape types along a gradient of wetland availability, we identified patterns in their daily movement behaviour and quantified potential effects of weather conditions and water availability on the spatial scale of their movements. Results: We demonstrate that mallard movement patterns were highly predictable, with regular commuting flights at dusk and dawn between a fixed day roost and one or several fixed nocturnal foraging sites, linked strongly to surface water. Wind and precipitation hardly affected movement, but flight distances and home range sizes increased when temperatures dropped towards zero. Flight distances and home range sizes increased exponentially with decreasing availability of freshwater habitat. Total shoreline length and the number of water bodies in the landscape surrounding the roost were the best predictors of the spatial scale of daily mallard movements. Conclusions: Our results show how mallards may flexibly adjust the spatial scale of their movements to wetland availability in the landscape. This implies that mallards moving between discrete habitat patches continue to preserve biotic connectivity in increasingly fragmented landscapes. The high predictability of mallard movement behaviour in relation to landscape features makes them reliable dispersal vectors for organisms to adapt to, and allows prediction of their ecological role in other landscapes.

研究背景：运动行为是动物生态学及其与其他生物相互作用的核心基础，由此亦对生态系统动态过程产生重要贡献。水禽通过捕食-被捕食相互作用、营养物质与其他生物的转运，在湿地及周边生境的生态过程中扮演关键角色。解析其运动行为的驱动因素，对于预测环境变化如何影响它们在生态系统功能中的作用至关重要。绿头鸭（Mallard，*Anas platyrhynchos*）是全球数量最多的鸭类物种，同时也是水生无脊椎动物、植物以及禽流感病毒等病原体的重要传播媒介。本研究通过对四种湿地可利用性梯度景观类型中的97只绿头鸭进行GPS追踪，明确了其日常运动行为模式，并量化了气象条件与水体可利用性对其运动空间尺度的潜在影响。研究结果：本研究显示，绿头鸭的运动模式具有高度可预测性：它们会在黄昏与黎明时段于固定的日间休憩地与一处或多处固定的夜间觅食地之间进行规律性往返飞行，且该行为与地表水体紧密相关。风力与降水几乎不对其运动产生影响，但当气温降至冰点附近时，飞行距离与家域范围会随之扩大。飞行距离与家域范围会随着淡水生境可利用性的降低呈指数级增长。休憩地周边景观中的总岸线长度与水体数量，是预测绿头鸭每日运动空间尺度的最优指标。研究结论：本研究结果阐明了绿头鸭如何根据景观内湿地可利用性，灵活调整自身运动的空间尺度。这意味着，在日益破碎化的景观中，穿梭于离散生境斑块间的绿头鸭仍可维持生物连通性。绿头鸭运动行为与景观特征的高度可预测性，使其成为其他生物适应环境时可依赖的传播媒介，同时也为预测其在其他景观中的生态角色提供了可能。