Gestich Carla C, Caselli Christini B, Nagy-Reis Mariana B, Setz Eleonore Z F, da Cunha Rogério G T
Departamento de Biologia Animal, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil.
Departamento de Ciências Biológicas, Universidade Federal Rural de Pernambuco, Recife, Pernambuco, Brazil.
Am J Primatol. 2017 Feb;79(2):1-9. doi: 10.1002/ajp.22586. Epub 2016 Jul 27.
Accurate measures of animal population densities are essential to assess their status, demography, and answer ecological questions. Among several methods proposed to collect abundance data, line transect sampling is used the most. The assumptions required to obtain accurate density estimates through this method, however, are rarely met when studying primates. As most primate species are vocally active, density estimates can be improved by associating transect sampling with playback point counts to scan the entire study area. Yet, attention to playback procedure and data collection design is necessary. Here, we describe a protocol to assess primate densities using playback and test its application on surveys of Callicebus nigrifrons, a small Neotropical primate that shows site fidelity and active vocal behavior. We list important steps and discuss precautions that should be considered, from the adjustments in the recordings in the lab to field procedures in the playback broadcasting sessions. Prior to the surveys, we conducted playback trials with three habituated wild groups at three forest remnants to test their response to the playback stimuli at different distances. Based on these trials, we defined the radius distance covered by the playback sessions. Then, we conducted two surveys in 12 forest remnants, in the northeast of São Paulo State Brazil. The results of density estimates were consistent between the two surveys. As the playback survey protocol we described has proved to be a simple and useful tool for surveying vocal primate and generated reliable data, we suggest that it is a good alternative method to estimate density of species, particularly for those that are responsive to playbacks and show site fidelity.
准确测量动物种群密度对于评估它们的生存状况、种群统计学特征以及回答生态学问题至关重要。在为收集丰富度数据而提出的几种方法中，线 transect 抽样是使用最广泛的。然而，在研究灵长类动物时，通过这种方法获得准确密度估计所需的假设很少能得到满足。由于大多数灵长类物种在发声方面很活跃，通过将 transect 抽样与回放点计数相结合以扫描整个研究区域，可以提高密度估计的准确性。然而，必须注意回放程序和数据收集设计。在这里，我们描述了一种使用回放来评估灵长类动物密度的方案，并在对 Callicebus nigrifrons（一种小型新热带灵长类动物，表现出对地点的忠诚度和活跃的发声行为）的调查中测试其应用。我们列出了重要步骤，并讨论了应考虑的预防措施，从实验室录音的调整到回放广播环节的现场程序。在调查之前，我们在三个森林残余地对三个习惯化的野生群体进行了回放试验，以测试它们在不同距离对回放刺激的反应。基于这些试验，我们确定了回放环节覆盖的半径距离。然后，我们在巴西圣保罗州东北部的 12 个森林残余地进行了两次调查。两次调查的密度估计结果一致。由于我们描述的回放调查方案已被证明是一种用于调查发声灵长类动物的简单且有用的工具，并产生了可靠的数据，我们建议它是估计物种密度的一种很好的替代方法，特别是对于那些对回放有反应且表现出对地点忠诚度的物种。
