Data from: Puma predation subsidizes an obligate scavenger in the high Andes

The ungulate–carnivore–vulture complex is a key trophic module of many terrestrial ecosystems, but one that is globally under threat. Few have explored cross-species dependencies in this module, and the degree to which vultures rely on trophic facilitation by apex carnivores is rarely known and almost never quantified.

We investigated the importance of puma Puma concolor predation on its native camelid prey, vicuñas Vicugna vicugna and guanacos Lama guanicoe, in food provisioning for Andean condors Vultur gryphus in the high Andes of north-western Argentina. We evaluated the origin of wild food sources through carcass surveys. We quantified condor feeding habits via foraging observations and through the analysis of pellet contents and stable isotopes from moulted feathers.

Of the 102 fresh camelid carcasses we monitored nearly all (94%) resulted from puma predation, and the majority (85%) of camelid carcasses used by condors were killed by pumas. Camelids represented 88% of the prey items identified from 183 condor pellets, and isotopic analyses of moulted feathers from 86 individuals identified via multilocus genotyping revealed that camelids and livestock were the most important prey items, representing 45–58% and 23–38% of condor assimilated biomass, respectively.

Synthesis and applications. Our results show that puma predation plays a key role in the foraging ecology of Andean condors, and highlight the importance of predatory processes that make carrion available to scavengers. We contend that targeting the conservation of ungulate–carnivore–vulture modules, rather than a species-specific approach, will be a more effective strategy to ensure the long-term persistence of Andean condors and other obligate scavengers.

有蹄类-食肉动物-秃鹫复合群落是诸多陆地生态系统的核心营养模块，同时也是全球范围内受威胁的生态单元之一。跨物种依存关系在此类群落中鲜有研究，秃鹫对顶级食肉动物提供的营养支持的依赖程度，既鲜为人知，也几乎从未被量化过。

我们以阿根廷西北部安第斯高海拔区域为研究区域，探究美洲狮（Puma concolor）对本土骆驼科猎物——骆马（Vicugna vicugna）与原驼（Lama guanicoe）的捕食行为，在为安第斯神鹫（Vultur gryphus）提供食物资源中的重要作用。我们通过尸体调查评估了野生食物资源的来源，并通过觅食观测、食丸内容物分析以及换羽羽毛的稳定同位素分析，量化了安第斯神鹫的食性特征。

在我们监测的102具新鲜骆驼科动物尸体中，几乎全部（94%）均由美洲狮捕食所致；而安第斯神鹫利用的骆驼科动物尸体中，绝大多数（85%）亦为美洲狮捕杀所得。在从183份安第斯神鹫食丸中鉴定出的猎物类群里，骆驼科动物占比达88%；通过多位点基因分型（multilocus genotyping）确定的86份换羽羽毛的同位素分析结果显示，骆驼科动物与家畜为安第斯神鹫最重要的猎物类群，分别占其同化生物量的45%~58%与23%~38%。

综合与应用。本研究结果表明，美洲狮捕食行为在安第斯神鹫的觅食生态中发挥核心作用，同时凸显了捕食过程为食腐动物提供腐尸资源的重要性。我们主张，相较于单一物种保护策略，聚焦有蹄类-食肉动物-秃鹫复合群落的保护方案，将是保障安第斯神鹫与其他专性食腐动物长期存续的更有效途径。