Spatial visual acuity of the falcon, Falco berigora: A behavioural, optical and anatomical investigation

  title={Spatial visual acuity of the falcon, Falco berigora: A behavioural, optical and anatomical investigation},
  author={Liz Reymond},
  journal={Vision Research},
  • L. Reymond
  • Published 31 December 1987
  • Psychology
  • Vision Research
Spatial contrast sensitivity and grating acuity of barn owls.
The eyes of barn owls (Tyto alba pratincola) display very little aberrations, and have thus excellent optical quality. In a series of behavioral experiments, we tested whether this presumably
Comparative neurophysiology of spatial luminance contrast sensitivity
The luminance contrast sensitivity function has been investigated using behavioral and electrophysiological methods in many vertebrate species. Some features are conserved across species as a shape
Visual adaptations of diurnal and nocturnal raptors.
Night vision in barn owls: visual acuity and contrast sensitivity under dark adaptation.
It is argued that the visual system of barn owls is designed to yield as much visual acuity under low light conditions as possible, thereby sacrificing resolution at photopic conditions.
Fundamentals of spatial vision in the barn owl (Tyto alba pratincola) : ocular aberrations, grating acuity, contrast sensitivity, and vernier acuity
Optical quality in barn owl eyes is presented in terms of measuring the ocular wavefront aberrations with a standard Tscherning-type wavefront aberrometer under natural viewing conditions and the results suggest that image quality in Barn Owl eyes is excellent.
Comparison of functional and anatomical estimations of visual acuity in two species of coral reef fish
Comparison of behavioural and anatomical estimates of visual acuity in coral reef fish reveals higher values for anatomical estimates but these may not be indicative of actual performance, and suggests that there is unlikely to be a simple scaling factor to link the two measures across all fish species.


Falcon visual sensitivity to grating contrast
It is reported that the cut-off frequency (a measure of visual acuity) is twice the expected value and is the same for kestrel and human eyes.
Falcon visual acuity.
This behavioral test of falcon acuity supports the common belief that Falconiformès have superb vision, although Falcon acuity was much more dependent on lumanance, declining sharply with decreases in luminance.
Monocular versus Binocular Visual Acuity
The technique of Schade1 is modified so that a grating target is generated on an oscilloscope by supplying suitable signals to the x, y and z axes, and it could be continuously varied both in contrast and fineness without the mean luminance of the screen changing.
Ocular Optical Filtering
The purpose of this chapter is to review the effects of optical filtering on eye function emphasizing such unresolved issues, for example, as the function of optical filters in the eyes of animals with high (suprahuman) visual acuity.
Information capacity of eyes
A comparative study of deep avian foveas.
Comparisons of foveal cell densities across species showed an increase in the average number of cells/visual degree2 with increasing eye size; similarly, an increase occurred in receptor nuclei relative to ganglion cell density; thus, smaller eyes showed a coarser retinal grain and a lower 'concidence ratio' of receptors toganglion cells than was found in the largest eyes.