What factors relate with the activity synchronization intensity among big cats and their ungulate prey in Northeast China?

Abstract

The activity synchronization rhythm is an important aspect of measuring interspecific interactions between predators and prey, and crucial for large carnivores conservation. However, little is known about what factors relate their activity synchronization dynamics. With the climate change and human society development, the spatial-temporal distribution and activity synchronized rhythm of large carnivores and their prey would inevitably be affected, which would further affect the adaptability of large carnivores and bring new challenges to their conservation. In this study, we hypothesized the ambient temperature and human activity would influence the activity synchronization intensity among Amur tiger, Amur leopard and ungulates (roe deer, sika deer and wild boar) through cross-correlation function and temporal niche overlap model based on the camera traps data. The result show that the activity rhythms of the five target species showed species and seasonal differences, the temporal niche overlaps between ungulates were normally higher than that between the cats and prey, the weakest overlap was observed between the two big cat species, and time-lags of similar rhythmic activity can reduce the temporal overlap pressures of species. Furthermore, we found that ambient temperature relate interspecific synchrony of roe deer-sika deer and roe deer-wild boar pairs at the daily scale. And at hourly scale, temperature and human activities exerted significantly positive or negative stresses on the interspecific activity synchronization of all target species, observed in all three seasons. Our study provides new insights on our understanding of the mechanisms by which sympatric predators and ungulate prey coexist and interact in view of temporal niche overlap, as well as how wildlife managers can manage the mammal assembly effectively. As the Amur tiger and leopard populations in China are being recovered quickly, the rapidly increasing predation pressure and limited environmental resources could have profound implications for the interaction and coexistence among these two large carnivores and their ungulate prey. Managers should strengthen the monitoring, and understand its causes and consequences, so as to develop effective protective measures.