Perspectives in Ecology and Conservation ( IF 4.7 ) Pub Date : 2021-04-20 , DOI: 10.1016/j.pecon.2021.03.009 Diogo Alexandre de Souza , André Luis Sousa Gonçalves , Eduardo Matheus von Muhlen , Vera Maria Ferreira da Silva
Understanding the distribution and abundance of threatened species is crucial to elaborate effective management plans for wild populations; however, elusive species prove difficult to detect. To support conservation strategies for the Vulnerable Amazonian manatee (Trichechus inunguis), the only freshwater sirenian, we analyzed presence/absence data with hierarchical models based on imperfect detection to assess T. inunguis occupancy in a Sustainable Development Reserve, Brazilian Central Amazon. In parallel, we compared the effectiveness of direct and indirect sampling methods to provide occupancy (ψ) and detection (p) estimates. Combining both sampling methods’ presence datasets provided higher accuracy estimates. The Amazonian manatee’s detection probability had never been estimated before: surprisingly, it was high (p = 0.50, SD = 0.05) and positively related with macrophyte coverage. Results suggest that the studied communities resident impact is not affecting the manatee occupancy, with greatest probabilities closer to human settlements. The final occupancy estimate obtained (ψ = 0.85, SD = 0.12) can be a baseline to Amazonian manatee long-term monitoring studies, and provide support for decision makers and local communities to establish effective protection zones for the species. Our approach highlights the potential of hierarchical models to understand the distribution not only of T. inunguis in different habitats, but also of other threatened Amazonian aquatic mammals.
中文翻译:
估计巴西亚马逊中部亚马逊海牛 (Trichechus inunguis) 的占有率和检测概率
了解受威胁物种的分布和丰度对于制定有效的野生种群管理计划至关重要;然而,难以捉摸的物种被证明很难被发现。为了支持脆弱的亚马逊海牛 ( Trichechus inunguis )(唯一的淡水海牛)的保护策略,我们使用基于不完善检测的分层模型分析了存在/不存在数据,以评估巴西亚马逊中部可持续发展保护区中的海牛数量。同时,我们比较了直接和间接采样方法在提供占用率 ( ψ ) 和检测 ( p) 方面的有效性估计。结合两种采样方法的存在数据集提供了更高的准确度估计。亚马逊海牛的发现概率以前从未被估计过:令人惊讶的是,它很高(p = 0.50,SD = 0.05)并且与大型植物覆盖率呈正相关。结果表明,所研究的社区居民影响不影响海牛的居住,最靠近人类住区的可能性最大。获得的最终占用率估计值 ( ψ = 0.85, SD = 0.12) 可以作为亚马逊海牛长期监测研究的基线,并为决策者和当地社区建立有效的物种保护区提供支持。我们的方法强调了分层模型的潜力,不仅可以理解T. inunguis在不同的栖息地,还有其他受威胁的亚马逊水生哺乳动物。