Effect of detection heterogeneity in occupancy-detection models: an experimental test of time-to-first-detection methods

Imperfect detection can bias estimates of site occupancy in ecological surveys but can be corrected by estimating detection probability. Time-to-first-detection (TTD) occupancy models have been proposed as a cost-effective survey method that allows detection probability to be estimated from single site visits. Nevertheless, few studies have validated the performance of occupancy-detection models by creating a situation where occupancy is known, and model outputs can be compared with the truth. We tested the performance of TTD occupancy models in the face of detection heterogeneity using an experiment based on standard survey methods to monitor koala (Phascolarctos cinereus) populations in Australia. Known numbers of koala faecal pellets were placed under trees, and observers, uninformed as to which trees had pellets under them, carried out a TTD survey. We fitted five TTD occupancy models to the survey data, each making different assumptions about detectability, to evaluate how well eac...

生态调查中的不完全检测（imperfect detection）会导致生境占用（site occupancy）估计结果出现偏倚，但可通过估算检测概率予以校正。首次检测耗时（Time-to-first-detection, TTD）占用模型被提出为一种高成本效益的调查方法，其可通过单次站点访问完成检测概率的估算。然而，目前鲜有研究通过构建已知真实生境占用状态的场景，将模型输出与真实值进行对比，以此验证占用-检测模型的实际表现。本研究依托监测澳大利亚考拉（Phascolarctos cinereus）种群的标准调查方法开展受控实验，以此检验存在检测异质性（detection heterogeneity）时TTD占用模型的表现。研究人员将已知数量的考拉粪便颗粒放置于树下，不知情的观察者（无法得知哪棵树下放置了粪便颗粒）开展了TTD调查。我们针对本次调查数据拟合了5种TTD占用模型，每种模型对可检测性做出了不同假设，以评估各模型的……