Comments |
Abstract: "Among various bird groups, the foveal pit may have two depths, shallow (80-120 µm) or deep (190-240 µm)." P.189 left column: "Among different bird groups, there are two ranges of foveal depths: the central foveas of accipitriform, falconiform, coraciiform and passeriform birds have mean depths between 190 and 240 µm (in the mean, 218.6 ± 52.0 µm: n = 50), whereas the central foveas of psittaciform birds and domestic pigeons, as well as the temporal foveas of accipitriform, falconiform, coraciiform and strigiform birds, have mean depths between 80 and 120 µm (92.2 ± 51.0 µm: n = 36: p < 0.001: Figure 5b,c). The data suggest that the depth of the foveal pit does not explain the differences between the visual acuities of different bird groups." |