Meeting Abstract
The use of the phrase “eagle eye” illustrates the widespread belief that birds have sharp spatial vision. Although some birds of prey do show visual acuity measurements finer than humans, these studies are limited to just a few species. In order to understand the visual capabilities of birds in general, we conducted a literature review of avian visual acuity (n = 88 unique species). We find that the median visual acuity in birds is approximately 10 cycles per degree, or around six times coarser than that of humans. Using phylogenetic generalized least squares, we examine how several behavioral (activity pattern, diet), ecological (habitat), and morphological (body and eye size) factors correlate with variation in avian visual acuity. This study helps explain how visual abilities may (or may not) be adapted to an animal’s needs. Additionally, by exploring how ecology and morphology influence visual acuity, we uncover underlying relationships that allow researchers to predict the visual acuity of their study species when formal measurements may be lacking.
