HawkEar: A bird‐borne visual and acoustic platform for eavesdropping the behaviour of mobile animals

Abstract

Unoccupied aerial vehicles (UAVs; drones) offer mobile platforms for ecological investigation, but can be impractical in some environments and the resulting noise can disturb wildlife. We developed a mobile alternative using a bird‐borne platform to record the behaviour of other animals in the field. This unit consists of a lightweight audio and video sensor that is carried by a trained Harris's hawk Parabuteo unicinctus. We tested the hypothesis that our bird‐borne platform is a viable option for collecting behavioural data from mobile animals. We recorded acoustic and video data as the hawk flew through a dense group of Brazilian free‐tailed bats Tadarida brasiliensis emerging from a cave, with a test case of investigating how echolocation calls change depending on spatial position in the bat group. The HawkEar platform is an alternative for collecting behavioural data when a mobile platform that is less noisy and restrictive than traditional UAVs is needed. The design and software are open source and can be modified to accommodate additional sensor needs.