Differential Use of Trails by Forest Mammals and the Implications for Camera-Trap Studies: A Case Study from Belize
Differential Use of Trails by Forest Mammals and the Implications for Camera-Trap Studies: A Case Study from Belize
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DOI：
10.1111/j.1744-7429.2009.00544.x
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发表时间：
2010-01-01
期刊：
影响因子：
2.1
通讯作者：
Doncaster, C. Patrick
中科院分区：
文献类型：
--
作者：
Harmsen, Bart J.;Foster, Rebecca J.;Doncaster, C. Patrick
相对丰度指数常用于比较不同地点间的物种丰度。这些指数假设物种具有相似的检测概率，或者检测概率之间的差异是已知的并且可以校正。指数通常由足迹、洞穴、标记或沿轨迹或样线拍摄的照片的遇到频率组成，但相等检测概率的假设很少得到验证。本研究利用相机陷阱和跟踪数据，分析了在茂密次生林小径上一系列新热带哺乳动物的探测概率。两种大型猫科动物美洲虎（Panthera onca）和美洲狮（Puma concolor）的照片捕获仅与路径变量相关，而其潜在猎物物种的照片捕获与路径变量无相关或负相关。根据足迹调查，新热带哺乳动物在跟随或穿越足迹的倾向上差异很大。这表明摄像机在轨迹上的位置对这些新热带哺乳动物有不同的检测概率。即使是两种大小相似的美洲虎和美洲狮，占据着相对相似的生态位，在使用小路上也有微妙的不同。美洲狮更完全地跟随足迹，而美洲虎更有可能偏离足迹。这些发现的生态意义在于，美洲虎似乎比美洲狮更愿意利用远离小径的森林基质。我们的结论是，基于足迹的指数，如照片捕捉或沿着足迹的足迹，不适合新热带物种之间的比较，甚至不适合相对相似的物种，如美洲虎和美洲狮。
Relative abundance indices are often used to compare species abundance between sites. The indices assume that species have similar detection probabilities, or that differences between detection probabilities are known and can be corrected for. Indices often consist of encounter frequencies of footprints, burrows, markings or photo captures along trails or transect lines, but the assumption of equal detection probabilities is rarely validated. This study analyzes detection probabilities of a range of Neotropical mammals on trails in dense secondary forests, using camera-trap and track data. Photo captures of the two large cats, jaguars (Panthera onca) and pumas (Puma concolor), were correlated solely with trail variables, while photo captures of their potential prey species had no correlation or negative correlation with trail variables. The Neotropical mammals varied greatly in their tendency to follow or cross trails based on footprints surveys. This indicates that camera locations on trails will have varying detection probability for these Neotropical mammals. Even the two similar-sized jaguars and pumas, occupying relatively similar niches, differed subtly in their use of trails. Pumas followed trails more completely while jaguars were more likely to deviate from trails. The ecological significance of these findings is that jaguars seem to be more willing to use the forest matrix away from trails than do pumas. We conclude that trail-based indices, such as photographic captures or tracks along trails, are not appropriate for comparison between Neotropical species, and not even between relatively similar species like jaguars and pumas.