PS 80-206
Bioacoustic location: Testing the effectiveness of two- and three-dimensional wireless recorder arrays
Microphone array monitoring is a remote-sensing method that uses acoustic triangulation to locate and study vocalizing animals within their natural habitat with minimal observer effects. It can be used to study secretive, rare and other hard to observe animals such as those inhabiting tall forest canopies. When set around a central area of interest, such as an active nesting site, recorders can capture activities of birds in various locations within and outside of an array. Past studies have used two-dimensional array systems, but there is a lack of research on three-dimensional wireless arrays focusing on bird localization. We tested the localization accuracy of an array comprised of four recorders in two-dimensional and three-dimensional space to triangulate relative bird call locations. The recorders were set up in field and forest environments using a protocol from Mennill et al. (2012). Pre-recorded sounds were emitted using bird song and a sport whistle at designated positions, and localization accuracy was calculated using the Sound Finder location software from Wilson et al. (2013).
Results/Conclusions
Three-dimensional setups were able to estimate horizontal and vertical locations of calls successfully, and future accuracy may be improved by using additional recorders. By testing in both field and forest environments using two-dimensional and three-dimensional arrays we were able to obtain data demonstrating how capable these recorders are at triangulating vocalizations in varying habitats and configurations. Two-dimensional arrays had a location accuracy of 6.45 ± 0.69 m standard error, and habitat type proved to be insignificant (p = 0.2154). Initial results for location accuracy of three-dimensional arrays are similar to the two-dimensional accuracy. Array monitoring can be a valuable tool for studying niche specialization and behavioral analyses of birds in both two and three dimensions.