In species with frontally placed eyes, visual targets are associated with the frontal orientation of the head.

For instance, some species have their orbits frontally placed in the skull (e.g., primates), while others have them laterally placed (e.g., birds, lizards). However, determining targets of visual attention can be challenging because visual systems vary between taxa. Additionally, measuring the targets of visual attention can have important methodological applications for the study of animal communication, social interactions, food search, mate choice, and anti-predator behavior in multiple taxa –. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Ĭompeting interests: The authors have declared that no competing interests exist.Įstablishing what animals are looking at has intrigued zoologists –, because it can help understand not only the mechanisms of visual information gathering (i.e., detection of color, motion, size, etc.), but also the processes behind visual attention (i.e., object recognition, reduction in visual uncertainty, etc.). CTO received funding from the 2008 California State University, Long Beach, Provost's Graduate Student Summer Research Award. This is an open-access article distributed under the terms of the Creative Commons Public Domain declaration which stipulates that, once placed in the public domain, this work may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose.įunding: This study was funded by National Science Foundation DBI-0641550. Received: MaAccepted: JPublished: September 22, 2010 PLoS ONE 5(9):Įditor: Eric Warrant, Lund University, Sweden

Higher translational head movement rates may be a strategy to compensate for the reduced degree of eye movement of this species.Ĭitation: O'Rourke CT, Pitlik T, Hoover M, Fernández-Juricic E (2010) Hawk Eyes II: Diurnal Raptors Differ in Head Movement Strategies When Scanning from Perches. Finally, American Kestrels have the highest rates of translational head movements (vertical or frontal displacements of the head keeping the bill in the same direction), which have been associated with depth perception through motion parallax. On the other hand, Red-tailed Hawks showed long intervals between consecutive head movements, which is consistent with prey searching in less visually obstructed environments (e.g., open habitats) and with detecting prey movement from a distance with their central foveae. Cooper's Hawks had the highest rate of regular head movements, which can facilitate tracking prey items in the visually cluttered environment they inhabit (e.g., forested habitats). We used behavioral recording of individuals under field and captive conditions to calculate the rate of two types of head movements and the interval between consecutive head movements.

Birds of prey eyes vector