Data from: Camera trap placement and the potential for bias due to trails and other features

Camera trapping has become an increasingly widespread tool for wildlife ecologists with large numbers of studies relying on photo capture rates or presence/absence information. It is increasingly clear that camera placement can directly impact this kind of data, yet these biases are poorly understood. We used a paired camera design to investigate the effect of small-scale habitat features on species richness estimates, and capture rate and detection probability of mammal species in the Shenandoah Valley of Virginia, USA. Cameras were deployed at either log features or on game trails with a paired camera at a nearby random location. Overall capture rates were significantly higher at trail and log cameras compared to their paired random cameras, and some species showed capture rate increases as high as 9.7 times greater at feature-based cameras. We recorded more species at both log (17) and trail features (15) than at their paired control sites (13 and 12 species, respectively) yet richness estimates were indistinguishable after 659 and 385 camera nights of survey effort, respectively, for log and trail features. We detected significant increases (ranging from 11-33%) in detection probability for 5 species resulting from the presence of game trails. Detection probability was also influenced by the presence of a log feature for six species. Bias was most pronounced for the three rodents investigated, where in all cases detection probability was substantially higher (24.9-38.2%) at log cameras. Our results indicate that small-scale factors, including the presence of game trails as well as other features, can have significant impacts on the frequency and probability of species detection when camera traps are employed. Significant biases may result if the presence and quality of these features are not documented and either incorporated into analytical procedures, or controlled for in study design.

红外相机陷阱（camera trapping）已日益成为野生动物生态学家广泛使用的研究工具，大量相关研究均依赖照片捕获率或物种存在/缺失信息开展分析。现有研究已愈发明确，相机布设位置会直接影响此类数据的准确性，但学界对这类采样偏差的认知仍较为匮乏。本研究采用配对相机布设方案，在美国弗吉尼亚州谢南多厄河谷（Shenandoah Valley）开展实验，探究小型生境特征对哺乳动物物种丰富度估计值、捕获率及检测概率的影响。研究将相机分别布设至倒木生境点（log features）与兽径（game trails）上，并在附近的随机点位设置配对对照相机。整体而言，兽径与倒木生境点处的相机捕获率显著高于配对的随机对照相机；部分物种在特征位点相机处的捕获率最高可达随机点位的9.7倍。本研究在倒木生境点（共记录17种）与兽径位点（共记录15种）处记录到的哺乳动物物种数均多于各自的对照随机点位（分别为13种与12种）；但当调查时长分别达到659个相机夜（camera nights）与385个相机夜后，二者的物种丰富度估计值不再存在显著差异。兽径的存在可使5个物种的检测概率显著提升，提升幅度介于11%至33%之间。倒木生境点的存在则会对6个物种的检测概率产生影响。在所研究的3种啮齿类动物中，采样偏差表现最为显著：所有物种在倒木位点相机处的检测概率均大幅提升，提升幅度为24.9%至38.2%。本研究结果表明，在使用红外相机陷阱开展调查时，兽径及其他小型生境特征等微观因素，会对物种的捕获频次与检测概率产生显著影响。若未记录此类生境特征的存在与质量，且未将其纳入分析流程或在研究设计中加以控制，则可能引入显著的采样偏差。

搜集汇总

背景与挑战

背景概述

该数据集基于配对相机设计，研究了小规模栖息地特征（如游戏路径和日志）对哺乳动物物种检测的偏差影响，发现路径和日志相机的捕获率和检测概率显著高于随机位置，特别是啮齿动物在日志相机处的检测概率大幅提高。研究强调了相机陷阱放置位置对数据准确性的重要性，并建议在野生动物监测中控制或记录这些特征以减少偏差。