Bhandari Aishwarya, Ghaskadbi Pallavi, Nigam Parag, Habib Bilal
Department of Animal Ecology and Conservation Biology Wildlife Institute of India Dehradun India.
Department of Wildlife Health and Management Wildlife Institute of India Dehradun India.
Ecol Evol. 2021 Mar 23;11(9):4774-4785. doi: 10.1002/ece3.7380. eCollection 2021 May.
In multipredator systems, group sizes of social carnivores are shaped by the asymmetric intraguild interactions. Subordinate social carnivores experience low recruitment rates as an outcome of predation pressure. In South and Southeast Asia, the Tiger (), Dhole (), and Leopard () form a widely distributed sympatric guild of large carnivores, wherein tigers are the apex predators followed by dhole and leopard. In this study, we attempted to understand the variation in pack size of a social carnivore, the dhole, at two neighboring sites in the Central Indian landscape. We further evaluated local-scale patterns of variation in pack size at a larger scale by doing a distribution-wide assessment across the dhole ranging countries. At the local scale, we found an inverse relationship between the density of tiger and pack size of dhole while accounting for variability in resources and habitat heterogeneity. Larger dhole packs (16.8 ± 3.1) were observed at the site where the tiger density was low (0.46/100 km), whereas a smaller pack size (6.4 ± 1.3) was observed in the site with high tiger density (5.36/100 km). Our results for the distribution-wide assessment were concordant with local-scale results, showing a negative association of pack size with the tiger densities (effect size -0.77) and a positive association with the prey abundance (effect size 0.64). The study advances our understanding to answer the age-old question of "what drives the pack size of social predators in a multipredator system?" This study also highlights the importance of understanding demographic responses of subordinate predator for varying competitor densities, often helpful in making informed decisions for conservation and management strategies such as population recovery and translocation of species.
在多捕食者系统中，群居食肉动物的群体规模受种内不对称相互作用的影响。从属群居食肉动物由于捕食压力而导致招募率较低。在南亚和东南亚，老虎（）、豺（）和豹（）构成了一个分布广泛的大型食肉动物同域群落，其中老虎是顶级捕食者，其次是豺和豹。在本研究中，我们试图了解群居食肉动物豺在印度中部景观中两个相邻地点的群体规模变化。我们还通过对豺分布范围内的国家进行全面评估，在更大尺度上进一步评估了群体规模变化的局部尺度模式。在局部尺度上，在考虑资源变异性和栖息地异质性的情况下，我们发现老虎密度与豺的群体规模之间存在负相关关系。在老虎密度较低（0.46/100平方公里）的地点观察到较大的豺群（16.8 ± 3.1），而在老虎密度较高（5.36/100平方公里）的地点观察到较小的群体规模（6.4 ± 1.3）。我们的全面评估结果与局部尺度结果一致，表明群体规模与老虎密度呈负相关（效应大小为-0.77），与猎物丰度呈正相关（效应大小为0.64）。这项研究推进了我们对“在多捕食者系统中，是什么驱动群居捕食者的群体规模？”这一古老问题的理解。这项研究还强调了了解从属捕食者对不同竞争密度的种群统计学反应的重要性，这通常有助于为保护和管理策略（如物种的种群恢复和迁移）做出明智决策。
