Department of Ecology, Evolution and Natural Resources, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.
Conserve Wildlife Foundation of New Jersey, Princeton, NJ, USA.
Sci Rep. 2022 Aug 18;12(1):14069. doi: 10.1038/s41598-022-18194-9.
Domestic dogs are the most abundant carnivore globally and have demonstrable negative impacts to wildlife; yet, little evidence regarding their functional roles in natural food webs exists. Adding dogs to food webs may result in a net loss (via suppression of naturally occurring species), net gain (via mesopredator release), or no change (via functional replacement) to ecosystem function. Scavenging is a pivotal function in ecosystems, particularly those that are energetically supported by carrion. Dogs also scavenge on animal carcasses, but whether scavenging by dogs influences the structural and functional properties of food webs remains unclear. Here we used camera traps baited with carrion to test the effect of dogs on the composition and diversity of the vertebrate scavenger guild, as well as carrion detection and consumption rates. We conducted this work in sandy beach ecosystems, which rely on the import of marine organic matter (i.e. stranding of dead marine animals). Diversity of the scavenger community was similar on beaches without dogs. Dogs increased the time it took for carcasses to be detected and decreased the proportion of carrion consumed. This 'dog suppression effect' on scavenging was stronger for nocturnal mammalian scavengers, presumably being driven by indirect trait-mediated effects, which raises further questions about the broader ecological consequences of domestic dogs in natural systems.
家犬是全球数量最多的肉食动物，对野生动物具有明显的负面影响；然而，关于它们在自然食物网中的功能作用的证据很少。在食物网中添加狗可能会导致净损失（通过抑制自然发生的物种）、净收益（通过中捕食者释放）或生态系统功能没有变化（通过功能替代）。食腐是生态系统中的一个关键功能，特别是那些以腐肉为能量支持的生态系统。狗也会在动物尸体上觅食，但狗的觅食行为是否会影响食物网的结构和功能特性尚不清楚。在这里，我们使用带有腐肉的摄像机陷阱来测试狗对脊椎动物食腐动物群体组成和多样性的影响，以及腐肉的检测和消耗率。我们在依赖海洋有机物输入（即死亡海洋动物搁浅）的沙滩生态系统中进行了这项工作。没有狗的海滩上，食腐动物群落的多样性相似。狗增加了腐肉被发现的时间，并减少了腐肉被消耗的比例。这种对食腐行为的“狗抑制效应”对夜间哺乳动物食腐动物更强，可能是由间接特征介导的效应驱动的，这进一步引发了关于在自然系统中家犬更广泛的生态后果的问题。
