Data from: Prey availability and ambient temperature influence carrion persistence in the boreal forest

Abstract1. Scavenging by vertebrates can have important impacts on food web stability and persistence, and can alter the distribution of nutrients throughout the landscape. However, scavenging communities have been understudied in most regions around the globe, and we lack understanding of the biotic drivers of vertebrate scavenging dynamics. 2. In this paper, we examined how changes in prey density and carrion biomass caused by population cycles of a primary prey species, the snowshoe hare (Lepus americanus), influence scavenging communities in the northern boreal forest. We further examined the impact of habitat and temperature on scavenging dynamics. 3. We monitored the persistence time, time until first scavenger, and number of species scavenging experimentally-placed hare carcasses over four consecutive years in the southwestern Yukon. We simultaneously monitored hare density and carrion biomass to examine their influence relative to temperature, habitat, and seasonal effects. For the primary scavengers, we developed species-specific scavenging models to determine variation on the effects of these factors across species, and determine which species may be driving temporal patterns in the entire community. 4. We found that the efficiency of the scavenging community was affected by hare density, with carcass persistence decreasing when snowshoe hare densities declined, mainly due to increased scavenging rates by Canada lynx (Lynx canadensis). However, prey density did not influence the number of species scavenging a given carcass, suggesting prey abundance affects carrion recycling but not necessarily the number of connections in the food web. In addition, scavenging rates increased in warmer temperatures, and there were strong seasonal effects on the richness of the vertebrate scavenging community. 5. Our results demonstrate that vertebrate scavenging communities are sensitive to changes in species’ demography and environmental change, and that future assessments of food web dynamics should consider links established through scavenging.

Abstract1. 脊椎动物食腐行为可对食物网的稳定性与存续产生重要影响，并能改变营养物质在景观中的分布格局。然而，全球多数区域的食腐群落研究仍较为匮乏，我们对脊椎动物食腐动态的生物驱动因子仍缺乏认知。2. 本研究聚焦北方针叶林北部区域，探究主要猎物物种雪兔（Lepus americanus）的种群周期所引发的猎物密度与腐肉生物量变化，如何影响当地食腐群落；同时还分析了生境与温度对食腐动态的影响。3. 研究团队在育空西南部连续四年监测了实验放置的野兔尸体的存留时间、首次被食腐动物造访的时间，以及参与食腐的物种数量；同时同步监测雪兔种群密度与腐肉生物量，以分析其相较于温度、生境与季节效应的影响。针对主要食腐物种，研究构建了物种特异性食腐模型，以明确各类因子对不同物种的影响差异，并判断哪些物种主导了整个食腐群落的时间动态模式。4. 研究结果显示，食腐群落的效率受雪兔种群密度影响：当雪兔密度下降时，尸体存留时间会缩短，这主要源于加拿大猞猁（Lynx canadensis）食腐率的提升。不过，猎物密度并不会影响单具尸体的食腐物种数量，这表明猎物丰度会影响腐肉循环，但未必会改变食物网中的关联数量。此外，温度升高会提升食腐率，且脊椎动物食腐群落的物种丰富度存在显著的季节效应。5. 本研究结果表明，脊椎动物食腐群落对物种种群动态与环境变化均较为敏感；未来的食物网动态评估应考虑食腐行为所建立的营养关联。