Use of autonomous audio recordings for the rapid inventory of birds in the white‐sand forests of the Peruvian Amazon

Abstract

White-sand forests are patchily distributed ecosystems covering just 5% of Amazonia that host many specialist species of birds not found elsewhere, and these forests are threatened due to their small size and human exploitation of sand for construction projects. As a result, many species of birds that area white-sand specialists are at risk of extinction, and immediate conservation action is paramount for their survival. Our objective was to evaluate current survey methods and determine the relative effect of the size of patches these forests on the presence or absence of white-sand specialist. Using point counts and autonomous recorders, we surveyed avian assemblages occupying patches of white-sand forest in the Peruvian Amazon in April 2018. Overall, we detected 126 species, including 21 white-sand forest specialists. We found that autonomous recorders detected significantly more species of birds per survey point than point counts. We also found a negative relationship between avian species richness and distance from the edge of patches of white-sand forest, but a significant, positive relationship when only counting white-sand specialists. While autonomous recorders detected more overall species, point counts were more effective for detecting canopy-dwelling passerines. Therefore, we recommend that inventories and surveys for rare and patchily distributed species in the tropics use a mixed-methods survey technique of bioacoustics and visual observations. Finally, conserving large, continuous patches of white-sand forest may increase survival likelihood for white-sand specialists, but future studies determining habitat occupancy should further investigate this relationship.