A comprehensive review of mammalian carnivore translocations

Carnivore conservation translocations are assumed to provide numerous ecological benefits, including conservation of the translocated carnivores, regulation of prey species and restoration of ecosystems. Reviews of mammalian carnivore conservation translocations and resultant ecosystem effects have focussed on large carnivores. We reviewed global terrestrial carnivore conservation translocations across all taxa, including taxonomic bias, problems influencing their population establishment and their ecosystem effects. We obtained data from 536 conservation translocations of 54 species of terrestrial mammalian carnivore (order Carnivora and family Dasyuridae, 30 g-196 kg), comprising mostly Mustelidae, Canidae, and Felidae species. A third of all projects translocated carnivores into South Africa and a third into fenced reserves. Significant bias occurred relative to threat status, with over-representation of Mustelidae and Canidae conservation translocations relative to the number of threatened species in each family. Additionally, conservation translocations of small carnivores were generally under-represented compared to those of large carnivores. Seventeen percent of small carnivore conservation translocations failed, compared with 25% of large carnivore conservation translocations; failure was primarily due to reported anthropogenic mortality. Effects on resident prey species or ecosystems of carnivore conservation translocations were rarely investigated. We found no significant relationship between the carnivore family or size and effects on prey or ecosystems; however, prey impacts were frequently attributed to Felidae, and ecosystem effects were frequently attributed to Canidae and Felidae. Challenges to translocations of mammalian carnivores include threats to resident threatened prey species and difficulties in monitoring the ecological effects of carnivore conservation translocations. Poor postrelease monitoring and a lack of empirical studies remain persistent problems, contributing to the poor understanding of ecosystem effects following carnivore conservation translocations.

Automated summary

This study reviewed global terrestrial carnivore conservation translocations and their effects on ecosystems. The results showed biases in taxonomic representation and a focus on large carnivores. Small carnivores were underrepresented and more prone to failure. The impacts of carnivore translocations on prey and ecosystems were rarely investigated, and there was a lack of post-release monitoring and empirical studies.