This study reports on experiments on falcons wearing miniature videocameras mounted on their backs or heads while pursuing flying prey. Videos of hunts by a gyrfalcon (Falco rusticolus), gyrfalcon (F. rusticolus)/Saker falcon (F. cherrug) hybrids and peregrine falcons (F. peregrinus) were analyzed to determine apparent prey positions on their visual fields during pursuits. These video data were then interpreted using computer simulations of pursuit steering laws observed in insects and mammals. A comparison of the empirical and modeling data indicates that falcons use cues due to the apparent motion of prey on the falcon's visual field to track and capture flying prey via a form of motion camouflage. The falcons also were found to maintain their prey's image at visual angles consistent with using their shallow fovea. These results should prove relevant for understanding the co-evolution of pursuit and evasion, as well as the development of computer models of predation and the integration of sensory and locomotion systems in biomimetic robots.
S.A.K. and M.Z. jointly digitized, analysed and interpreted the video data received from cooperating falconers. S.A.K. conceived of the experimental and computational study design, provided video equipment and instructions to the falconers, performed the computer modelling, and wrote the paper with input from M.Z. during the initial drafting and revisions.
The authors declare no competing financial interests.
This research was supported in part by a grant to Haverford College from the Howard Hughes Medical Institute and by a Special Projects Award from the Marion E. Koshland Integrated Natural Sciences Center of Haverford College.
- © 2014. Published by The Company of Biologists Ltd