University of Georgia Savannah River Ecology Laboratory, Warnell School of Forestry and Natural Resources, P.O. Box Drawer E, Aiken, SC, 29802, USA.
USDA-APHIS-WS, 400 Northeast Dr Suite L, Columbia, SC, 29203, USA.
Sci Rep. 2020 Feb 14;10(1):2644. doi: 10.1038/s41598-020-59560-9.
Carrion is a valuable resource used by facultative scavengers across the globe. Due to conflicts with humans, many vertebrate scavengers have experienced population declines due to direct persecution or indirect effects of human activities. However, little is known about the implications of altered scavenger community composition on the fate and efficiency of carrion removal within ecosystems. In particular, mammalian mesopredators are efficient scavengers that are often subjected to control, thus, it is important to understand how the reduction of this scavenger guild influences the fate of carrion resources and efficiency of carrion removal within ecosystems. We evaluated the influence of the absence of mammalian mesopredators on vertebrate scavenging dynamics by comparing the efficiency of carrion removal and species composition at carrion between sites where we experimentally manipulated mesopredator abundance and paired control sites. Overall scavenging rates were high, even within our mesopredator exclusion sites (79% of carcasses). Despite the exclusion of an entire guild of dominant scavengers, we saw little effect on scavenging dynamics due to the extensive acquisition of carrion by avian scavengers. However, we observed a slight reduction in vertebrate scavenging efficiency in sites where mesopredators were excluded. Our results suggest vertebrate communities are highly efficient at carrion removal, as we saw a functional response by avian scavengers to increased carrion availability. These data provide insights into the impact of mesopredator control on food web dynamics, and build upon the growing body of knowledge investigating the role of vertebrate scavengers on ecosystem services provided through carrion removal.
腐肉是全球兼性食腐动物的宝贵资源。由于与人类的冲突，许多脊椎动物食腐动物由于直接迫害或人类活动的间接影响而经历了数量下降。然而，对于改变的食腐动物群落组成对生态系统中腐肉去除的命运和效率的影响知之甚少。特别是，哺乳动物中型捕食者是高效的食腐动物，经常受到控制，因此，了解这个食腐动物群体的减少如何影响腐肉资源的命运和生态系统中腐肉去除的效率非常重要。我们通过比较在我们实验性地操纵中型捕食者丰度的地点和配对的对照地点之间的腐肉去除效率和物种组成，评估了哺乳动物中型捕食者不存在对脊椎动物食腐动态的影响。总体而言，即使在我们的中型捕食者排除地点，食腐率也很高（79%的尸体）。尽管排除了一个主导食腐者的整个群体，但由于鸟类食腐动物广泛获取腐肉，我们几乎没有看到食腐动态的影响。然而，我们在排除中型捕食者的地点观察到脊椎动物食腐效率略有降低。我们的研究结果表明，脊椎动物群落在腐肉去除方面非常高效，因为我们看到了鸟类食腐动物对增加的腐肉供应的功能反应。这些数据提供了关于中型捕食者控制对食物网动态影响的见解，并建立在越来越多的关于研究脊椎动物食腐动物在通过腐肉去除提供生态系统服务方面的作用的知识基础上。
