Data from: Loss of connectivity among island-dwelling Peary caribou following sea ice decline

Global warming threatens to reduce population connectivity for terrestrial wildlife through significant and rapid changes to sea ice. Using genetic fingerprinting, we contrast extant connectivity in island-dwelling Peary caribou in northern Canada with continental-migratory caribou. We next examined if sea-ice contractions in the last decades modulated population connectivity and explored the possible impact of future climate change on long-term connectivity among island caribou. We found a strong correlation between genetic and geodesic distances for both continental and Peary caribou, even after accounting for the possible effect of sea surface. Sea ice has thus been an effective corridor for Peary caribou, promoting inter-island connectivity and population mixing. Using a time series of remote sensing sea ice data, we show that landscape resistance in the Canadian Arctic Archipelago has increased by ~15% since 1979 and may further increase by 20 to 77% by 2086 under a high-emission scenario (RCP8.5). Under the persistent increase in greenhouse gas concentrations, reduced connectivity may isolate island-dwelling caribou with potentially significant consequences for population viability.

全球变暖可通过海冰的剧烈快速变化，削弱陆生野生动物的种群连通性。本研究借助遗传指纹图谱（genetic fingerprinting）技术，对比了加拿大北部岛屿栖息的皮尔里驯鹿（Peary caribou）与大陆洄游驯鹿现存的种群连通性。随后，我们分析了近数十年海冰缩减是否对种群连通性产生了调控作用，并探讨了未来气候变化对岛屿栖息驯鹿长期种群连通性的潜在影响。研究发现，即便控制了海表的潜在影响，大陆驯鹿与皮尔里驯鹿的遗传距离与测地距离（geodesic distances）均呈现显著相关性。由此可见，海冰一直是皮尔里驯鹿的有效扩散廊道，助力岛屿间的种群连通与基因混合。借助遥感海冰数据的时间序列，我们发现加拿大北极群岛（Canadian Arctic Archipelago）的景观阻力（landscape resistance）自1979年以来已提升约15%；在高排放情景（RCP8.5）下，到2086年该阻力或进一步上升20%至77%。若温室气体浓度持续攀升，种群连通性的下降可能会导致岛屿栖息驯鹿的种群隔离，进而对种群存续产生潜在的重大影响。