Tracking the gaze of birds

Accurate measurements of what birds are looking at are valuable to most studies of vision and visually guided behaviour in avian species. Compared to human visual research, studies of gaze behaviour in birds are limited. A new laser-based method that can be used to quantify several aspects of a given sequence of gaze shifts and fixations is presented. Using near infrared light to estimate gaze direction is a relatively simple and cheap method to study visually guided behaviour. It has the potential to contribute significantly to the ornithological research by allowing the quantification of several behavioural traits of birds. Other methods are discussed and compared to the use of infrared light, and possible fields of application are suggested.