What are flying birds looking at? New challenges in the use of cutting-edge sensor technologies to study bird gaze

Abstract

Birds and primates typically attend to an object of interest using sensitive spots in the retina (i.e. the fovea). Therefore, the direction of their gaze indicates their focus of attention. Recent technological advances in miniature wearable devices allow us to examine birds' gaze behaviors in detail when they are freely moving, and even when they are flying. In this review, I aim to outline current knowledge about how birds use their gaze to attend to an object of interest, and what they are attending to when they are engaging in various natural activities, such as navigation, vigilance, and social interaction. I also aim to outline both strengths and limitations of techniques available for bird gaze-tracking. As a relevant example, I introduce a recent study that utilized Inertial Measurement Unit to examine how pigeons move their gaze while attending to landscapes and flockmates during their homing flights. Overall, I believe that recent sensor technologies offer a promising avenue for examining birds' visual attention and the associated mental processes in natural contexts.