HawkEar: A bird-borne visual and acoustic platform for eavesdropping the behavior of mobile animals

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 behavior 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 behavioral 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 changes depending on spatial position in the bat group. The HawkEar platform is an alternative for collecting behavioral 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.