Data from: Movements of four native Hawaiian birds across a naturally fragmented landscape

Animals often increase their fitness by moving across space in response to temporal variation in habitat quality and resource availability, and as a result of intra and inter-specific interactions. The long-term persistence of populations and even whole species depends on the collective patterns of individual movements, yet animal movements have been poorly studied at the landscape level. We quantified movement behavior within four native species of Hawaiian forest birds in a complex lava-fragmented landscape: Hawai‛i ‘Amakihi (Chlorodrepanis virens), ‘Oma‘o (Myadestes obscurus), ‘Apapane (Himatione sanguinea), and ‘I‘iwi (Drepanis coccinea). We evaluated the relative importance of six potential intrinsic and extrinsic drivers of movement behavior and patch fidelity: 1) forest fragment size, 2) the presence or absence of invasive rats (Rattus sp.), 3) season, 4) species, 5) age, and 6) sex. The study was conducted across a landscape of 34 forest fragments varying in size from 0.07 to 12.37 ha, of which 16 had rats removed using a treatment-control design. We found the largest movements in the nectivorous ‘Apapane and ‘I‘iwi, intermediate levels in the generalist Hawai‛i ‘Amakihi, and shortest average movement for the ‘Oma‘o, a frugivore. We found evidence for larger patch sizes increasing patch fidelity only in the ‘Oma‘o, and an effect of rat-removal increasing patch fidelity of Hawai‛i ‘Amakihi only after two years of rat-removal. Greater movement during the non-breeding season was observed in all species, and season was an important factor in explaining higher patch fidelity in the breeding season for ‘Apapane and ‘I‘iwi. Sex was important in explaining patch fidelity in ‘Oma‘o only, with males showing higher patch fidelity. Our results provide new insights into how these native Hawaiian species will respond to a changing environment, including habitat fragmentation and changing distribution of threats from climate change.

动物通常会通过空间移动响应栖息地质量与资源可获得性的时间波动，同时因种内与种间相互作用发生移动，以此提升自身适合度。种群乃至整个物种的长期存续，依赖于个体移动的集体模式，但目前在景观尺度上对动物移动的研究仍较为匮乏。本研究在受熔岩活动碎片化的复杂景观中，对4种夏威夷本土林鸟的移动行为开展量化分析，涵盖夏威夷‘Amakihi（Chlorodrepanis virens）、‘Oma‘o（Myadestes obscurus）、‘Apapane（Himatione sanguinea）以及‘I‘iwi（Drepanis coccinea）。本研究评估了影响移动行为与斑块保真度（patch fidelity）的6种潜在内在与外在驱动因素的相对重要性：1）森林斑块面积；2）入侵鼠类（Rattus sp.）的存在与否；3）季节；4）物种；5）年龄；6）性别。本研究覆盖了34个面积介于0.07至12.37公顷的森林斑块，其中16个斑块通过对照处理设计开展了鼠类清除工作。研究结果显示，食蜜性的‘Apapane与‘I‘iwi的移动距离最长，广食性的夏威夷‘Amakihi移动距离处于中等水平，而作为食果动物的‘Oma‘o平均移动距离最短。研究发现，仅在‘Oma‘o种群中，更大的斑块面积会提升其斑块保真度；而鼠类清除仅在开展两年后，才会对夏威夷‘Amakihi的斑块保真度产生提升作用。所有物种均表现出非繁殖季移动性更强的特征；同时季节是解释‘Apapane与‘I‘iwi在繁殖季斑块保真度更高的重要因素。仅在‘Oma‘o种群中，性别对斑块保真度存在显著影响，雄性个体的斑块保真度更高。本研究结果为理解这些夏威夷本土物种如何响应环境变化，包括栖息地碎片化以及气候变化带来的威胁分布改变，提供了新的视角。