McLennan Elspeth A, Wise Phil, Lee Andrew V, Grueber Catherine E, Belov Katherine, Hogg Carolyn J
School of Life and Environmental Sciences University of Sydney Sydney New South Wales Australia.
Save the Tasmanian Devil Program NRE Hobart Tasmania Australia.
Ecol Evol. 2022 May 19;12(5):e8936. doi: 10.1002/ece3.8936. eCollection 2022 May.
Top carnivores are essential for maintaining ecosystem stability and biodiversity. Yet, carnivores are declining globally and current threat mitigations cannot halt population declines. As such, translocations of carnivores to historic sites or those outside the species' native range are becoming increasingly common. As carnivores are likely to impact herbivore and small predator populations, understanding how carnivores interact within an ecosystem following translocation is necessary to inform potential remedial management and future translocations. Dietary analyses provide a preliminary assessment of the direct influence of translocated carnivores on a recipient ecosystem. We used a metabarcoding approach to quantify the diet of Tasmanian devils introduced to Maria Island, Tasmania, a site outside the species' native range. We extracted DNA from 96 scats and used a universal primer set targeting the vertebrate 12S rRNA gene to identify diet items. Tasmanian devils on Maria Island had an eclectic diet, with 63 consumed taxa identified. Cat DNA was detected in 14% of scats, providing the first instance of cats appearing as part of Tasmanian devil diets either via predation or scavenging. Short-tail shearwaters and little penguins were commonly consumed, corresponding with previous surveys showing sharp population declines in these species since the introduction of Tasmanian devils. Our results indicate that the introduction of carnivores to novel ecosystems can be very successful for the focal species, but that commonly consumed species should be closely monitored to identify any vulnerable species in need of remedial management.
顶级食肉动物对于维持生态系统的稳定性和生物多样性至关重要。然而，全球范围内食肉动物数量正在减少，当前的威胁缓解措施无法阻止其种群数量下降。因此，将食肉动物转移到历史分布地或其原生范围之外的地区变得越来越普遍。由于食肉动物可能会影响食草动物和小型食肉动物的种群数量，了解食肉动物在转移后如何在生态系统中相互作用对于指导潜在的补救管理和未来的转移工作是必要的。饮食分析为评估转移的食肉动物对受纳生态系统的直接影响提供了初步依据。我们采用了一种元条形码方法来量化引入塔斯马尼亚州玛丽亚岛（该岛不在该物种的原生范围内）的袋獾的饮食。我们从96份粪便样本中提取了DNA，并使用一套针对脊椎动物12S rRNA基因的通用引物来识别食物种类。玛丽亚岛上的袋獾饮食多样，共识别出63种被食用的分类单元。在14%的粪便样本中检测到了猫的DNA，这是首次发现猫通过捕食或食腐成为袋獾饮食的一部分。短尾鹱和小企鹅是常见的食物，这与之前的调查结果相符，该调查显示自袋獾引入以来，这些物种的数量急剧下降。我们的研究结果表明，将食肉动物引入新的生态系统对于目标物种可能非常成功，但对于常见的被食用物种应密切监测，以识别任何需要补救管理的脆弱物种。
