Data from: Response of pumas (Puma concolor) to migration of their primary prey in Patagonia

Large-scale ungulate migrations result in changes in prey availability for top predators and, as a consequence, can alter predator behavior. Migration may include entire populations of prey species, but often prey populations exhibit partial migration with some individuals remaining resident and others migrating. Interactions of migratory prey and predators have been documented in North America and some other parts of the world, but are poorly studied in South America. We examined the response of pumas (Puma concolor) to seasonal migration of guanacos (Lama guanicoe) in La Payunia Reserve in northern Patagonia Argentina, which is the site of the longest known ungulate migration in South America. More than 15,000 guanacos migrate seasonally in this landscape, and some guanacos also are resident year-round. We hypothesized that pumas would respond to the guanaco migration by consuming more alternative prey rather than migrating with guanacos because of the territoriality of pumas and availability of alternative prey throughout the year at this site. To determine whether pumas moved seasonally with the guanacos, we conducted camera trapping in the summer and winter range of guanacos across both seasons and estimated density of pumas with spatial mark–resight (SMR) models. Also, we analyzed puma scats to assess changes in prey consumption in response to guanaco migration. Density estimates of pumas did not change significantly in the winter and summer range of guanacos when guanacos migrated to and from these areas, indicating that pumas do not follow the migration of guanacos. Pumas also did not consume more alternative native prey or livestock when guanaco availability was lower, but rather fed primarily on guanacos and some alternative prey during all seasons. Alternative prey were most common in the diet during summer when guanacos also were abundant on the summer range. The response of pumas to the migration of guanacos differs from sites in the western North America where entire prey populations migrate and pumas migrate with their prey or switch to more abundant prey when their primary prey migrates.大规模有蹄类动物迁徙会改变顶级捕食者的猎物可获得性，进而改变捕食者的行为模式。迁徙可能涵盖猎物物种的整个种群，但多数情况下猎种种群呈现部分迁徙模式：部分个体留居原地，其余个体则参与迁徙。迁徙猎物与捕食者的相互作用已在北美及全球其他部分地区得到记录，但在南美洲相关研究仍较为匮乏。本研究聚焦阿根廷巴塔哥尼亚北部拉帕尤尼亚保护区——已知南美洲规模最长的有蹄类迁徙栖息地——探讨美洲狮（Puma concolor）对原驼（Lama guanicoe）季节性迁徙的响应。该区域内超过15000头原驼会进行季节性迁徙，同时也有部分原驼全年留居。基于美洲狮的领地习性与该区域全年均可获得替代猎物的条件，本研究提出假说：美洲狮会通过捕食更多替代猎物来响应原驼的迁徙，而非跟随原驼一同迁徙。为探明美洲狮是否会随原驼进行季节性迁徙，本研究在原驼的夏季与冬季栖息地跨季开展红外相机监测，并借助空间标记重捕（spatial mark–resight, SMR）模型估算美洲狮种群密度。此外，本研究通过分析美洲狮粪样，评估其猎物摄入随原驼迁徙发生的变化。当原驼往返于夏、冬季栖息地时，美洲狮在原驼夏季与冬季栖息地内的种群密度均未发生显著变化，表明美洲狮并未跟随原驼迁徙。当原驼可获得性降低时，美洲狮并未增加对本土替代猎物或家畜的捕食，而是在全年均主要以原驼及少量替代猎物为食。夏季原驼在夏季栖息地内种群数量充足时，替代猎物在美洲狮食谱中的占比最高。美洲狮对原驼迁徙的响应模式，与北美西部的相关研究位点存在差异：在北美西部，猎种种群会整体迁徙，美洲狮要么跟随猎物一同迁徙，要么在主要猎物迁徙时转而捕食更为丰富的替代猎物。