title: Comparison of eye morphology and retinal topography in two species of New World vultures (Aves: Cathartidae).
abstract: Vultures are highly reliant on their sensory systems for the rapid detection and localization of carrion before other scavengers can exploit the resource. In this study, we compared eye morphology and retinal topography in two species of New World vultures (Cathartidae), turkey vultures (Cathartes aura), with a highly developed olfactory sense, and black vultures (Coragyps atratus), with a less developed sense of olfaction. We found that eye size relative to body mass was the same in both species, but that black vultures have larger corneas relative to eye size than turkey vultures. However, the overall retinal topography, the total number of cells in the retinal ganglion cell layer, peak and average cell densities, cell soma area frequency distributions, and the theoretical peak anatomical spatial resolving power were the same in both species. This suggests that the visual systems of these two species are similar and that vision plays an equally important role in the biology of both species, despite the apparently greater reliance on olfaction for finding carrion in turkey vultures.
authors.affiliation: Department of Psychology, University of Alberta, Edmonton, AB, Canada.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Lisney
authors.forename: Karyn
authors.initials: K
authors.lastname: Stecyk
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Kolominsky
authors.forename: Gary R
authors.initials: GR
authors.lastname: Graves
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Wylie
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Iwaniuk
mesh_terms: D000818:Animals; D001717:Birds / Q000033:anatomy & histology* / Q000145:classification; D005123:Eye / Q000033:anatomy & histology*; D012160:Retina / Q000033:anatomy & histology*; D012165:Retinal Ganglion Cells / Q000166:cytology; D013045:Species Specificity
keywords: Cathartes aura; Coragyps atratus; bird; olfaction; retinal ganglion cell; scavenging; sensory ecology; vision; visual acuity