Avoidance of carnivore carcasses by vertebrate scavengers enables colonization by a diverse community of carrion insects

Carrion resources sustain a complex and diverse community of both vertebrate and invertebrate scavengers, either obligate or facultative. However, although carrion ecology has received increasing scientific attention in recent years, our understanding of carrion partitioning in natural conditions is severely limited as most studies are restricted either to the vertebrate or the insect scavenger communities. Moreover, carnivore carcasses have been traditionally neglected as study model. Here, we provide the first data on the partitioning between vertebrate and invertebrate scavengers of medium-sized carnivore carcasses, red fox (Vulpes vulpes (Linnaeus)), in two mountainous Mediterranean areas of south-eastern Spain. Carcasses were visited by several mammalian and avian scavengers, but only one carcass was partially consumed by golden eagle Aquila chrysaetos (Linnaeus). These results provide additional support to the carnivore carrion-avoidance hypothesis, which suggests that mammalian carnivores avoid the consumption of carnivore carcasses to prevent disease transmission risk. In turn, the absence of vertebrate scavengers at carnivore carcasses enabled a diverse and well-structured successional community of insects to colonise the carcasses. The observed richness and abundance of the most frequent families was more influenced by the decomposition time than by the study area. Overall, our study encourages further research on carrion resource partitioning in natural conditions.

腐肉资源支撑着一个由专性食腐者与兼性食腐者共同组成的复杂多样的脊椎动物、无脊椎动物食腐群落。尽管近年来腐肉生态学（carrion ecology）受到的科研关注度与日俱增，但我们对自然条件下腐肉资源利用分化（carrion partitioning）的认知仍存在严重局限——绝大多数相关研究要么仅聚焦于脊椎动物食腐群落，要么仅针对昆虫食腐群落展开。此外，食肉动物尸体长期以来被忽视，未被用作研究模型。本研究首次报道了西班牙东南部两处地中海山地生境中，中型食肉动物尸体（以赤狐Vulpes vulpes Linnaeus为例）的脊椎动物与无脊椎动物食腐者之间的资源利用分化相关数据。研究发现，多种哺乳类与鸟类食腐动物造访了尸体，但仅有一具尸体被金雕Aquila chrysaetos Linnaeus部分取食。上述结果进一步支撑了食肉动物腐肉回避假说（carnivore carrion-avoidance hypothesis）：该假说提出，哺乳类食肉动物会避免取食同类食肉动物的尸体，以降低疾病传播风险。与此同时，食肉动物尸体上脊椎动物食腐者的缺失，使得多样且结构完整的昆虫演替群落得以定殖该尸体。研究观察到的常见昆虫科类群的丰富度与个体多度，更多受分解时长而非研究区域的影响。总体而言，本研究呼吁未来开展更多针对自然条件下腐肉资源利用分化的相关研究。