Cooperative Fish and Wildlife Research Units Program: New York
Education, Research and Technical Assistance for Managing Our Natural Resources

Growing economies in developing countries frequently come at the expense of conservation priorities, such as the protection of endangered species, the maintenance of ecosystem services, and the long-term sustainability of resources. Assessing the persistence of native wildlife, a measure of ecosystem health, in rapidly changing landscapes is challenging due to current limitations in methods to survey wildlife populations and analyze the resulting data. Population density is a metric commonly used to assess species status; however, estimating the density of species that are difficult to identify visually is challenging. Passive acoustic monitoring is a new survey method with the potential to provide quick and reliable population density estimates for species that are easy to detect acoustically; however, statistical methods that reliably produce in situ density estimates from acoustic data that are not dependent on human interpretation of call rates are currently undeveloped. We propose to extend recent developments in statistical models for other noninvasive sampling methods to the use of acoustic monitoring devices for density estimation by incorporating spatial information about the spatial structure of the population to produce estimates of call rate in situ, and in turn estimate density. In addition, we will expand on existing automated detection and classification techniques for processing the acoustic data which will allow us to incorporate information about caller identity into our estimates. As a case study in use of these methods, we are applying the methods to endangered gibbons in Borneo, Indonesia. This application will demonstrate how bioacoustics detectors can be used to estimate the density of other species which can be detected acoustically, leading to more reliable conservation and land use decisions worldwide for any vocalizing species.