Data for: Seasonal resource partitioning between neighboring cougars in a multi-prey system

Individual dietary variation in sexually dimorphic predator populations arises from phenotypic traits, preference, prey availability, and competition. We tested competing hypotheses for how diet similarity among cougars (Puma concolor) is influenced by sex, seasonal prey availability, and home range overlap in the southern interior of British Columbia, Canada. We proposed four hypotheses: (1) prey availability—overlapping individuals share similar diets due to access to the same prey base; (2) resource competition—overlapping individuals diverge in diet to minimize competition; (3) resource partitioning—diet similarity peaks at intermediate overlap; and (4) null—sex and season explain similarity irrespective of overlap. We analyzed diet data from 27 female and 11 male cougars (875 kill sites) and extrapolated prey availability from 146 remote cameras to test for sex-based differences in prey selection across winter, migration, and summer. We then used a pairwise approach to model diet similarity between individuals. Males generally killed larger prey (e.g., moose, elk), while females killed more deer, with differences in deer species selection in the Boundary study area where fewer large prey were available. We found support for resource partitioning between female–female dyads and for resource competition between male–female dyads. Diet similarity was lowest in summer when home ranges were largest and highest in winter when ranges were smallest. Our findings highlight the complexity of predation patterns and the roles of sexual dimorphism, seasonal prey availability, and resource partitioning in shaping prey use among spatially overlapping territorial predators in multi-prey systems.

性二态捕食者种群的个体食性变异，源自表型特征、食性偏好、猎物可获得性与种间竞争。本研究以加拿大不列颠哥伦比亚省南部内陆地区的美洲狮（Puma concolor）为研究对象，检验了性别、季节性猎物可获得性以及家域重叠度对个体间食性相似性的影响，并提出四项竞争性假说：
1. 猎物可获得性假说：家域重叠的个体因共享相同猎物资源库，食性趋于相似；
2. 资源竞争假说：家域重叠的个体通过食性分化以最小化种间竞争；
3. 资源分配假说：食性相似性在中等程度的家域重叠时达到峰值；
4. 零假设：食性相似性仅由性别与季节决定，与家域重叠度无关。

本研究分析了27只雌性与11只雄性美洲狮的食性数据（共计875个捕杀位点），并通过146台远程相机推断区域内猎物可获得性，以此检验冬季、迁徙季与夏季间基于性别的猎物选择差异。随后采用成对分析方法构建个体间食性相似性模型。

研究结果显示，雄性美洲狮通常捕杀体型更大的猎物（如驼鹿、马鹿），而雌性则更多捕食鹿类；在大型猎物匮乏的边界研究区域内，雌性对鹿类物种的选择存在显著差异。本研究支持雌性-雌性个体配对间的资源分配假说，以及雄性-雌性个体配对间的资源竞争假说。食性相似性在夏季（此时家域范围最大）最低，而在冬季（此时家域范围最小）最高。

本研究结果揭示了捕食模式的复杂性，以及性二态性、季节性猎物可获得性与资源分配在多猎物系统中，对空间重叠的领地捕食者猎物利用模式的塑造作用。