Abstract
The eye of a small falcon, the kestrel, is about half the size of the human eye and, if similar in all other respects, its visual acuity would also be expected to be about half that of the human. Here we report that the cut-off frequency (a measure of visual acuity) is twice the expected value and is the same for kestrel and human eyes. This remarkable visual performance is explained by anatomical features of the bird eye and the spherical pit of the deep fovea acting as the diverging element of a telephoto lens to magnify the image1,2. In the low-spatial frequency range, however, falcon contrast sensitivity is much less than that of humans for stationary patterns.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Snyder, A. & Miller, W. Nature 275, 127–129 (1978).
Miller, W. H. Handbook of Sensory Physiology Vol. 7/6A, 114–122 (Springer, Berlin, 1979).
Reymond, L. & Wolfe, J. Vision Res. 21, 263–271 (1981).
Patel, A. S. J. opt. Soc. Am. 56, 689–694 (1966).
Fox, R., Lehmkuhle, S. W. & Westendorf, D. Science 192, 263–265 (1976).
Fite, K. V. Brain Behav. Evol. 12, 97–155 (1975).
Walls, G. L. The Vertebrate Eye (Cranbrook Institute of Science, Bloomfield Hills, Michigan, 1972).
Shlaer, R. Science 276, 920–922 (1972).
Barlow, H. B. Photophysiology Vol. 2, 162–202 (Academic, New York, 1964).
Westheimer, G. Handbook of Sensory Physiology Vol. 7/2 (Springer, Berlin, 1972).
Pumphrey, R. J. in Biology and Comparative Physiology of Birds (ed. Marshall, A. J.) (Academic, New York, 1961).
Williams, D. S. & McIntyre, P. Nature 288, 578–580 (1980).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hirsch, J. Falcon visual sensitivity to grating contrast. Nature 300, 57–58 (1982). https://doi.org/10.1038/300057a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/300057a0
This article is cited by
-
Sight or smell: which senses do scavenging raptors use to find food?
Animal Cognition (2019)
-
Light and electron microscopic studies on the retina of the booted eagle (Aquila pennata)
Zoomorphology (2018)
-
Kontrastempfindlichkeit und Sehschärfe bei Tieren
Der Ophthalmologe (2017)
-
Avian contrast sensitivity inspired contour detector for unmanned aerial vehicle landing
Science China Technological Sciences (2017)
-
Luminance-dependence of spatial vision in budgerigars (Melopsittacus undulatus) and Bourke’s parrots (Neopsephotus bourkii)
Journal of Comparative Physiology A (2012)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.