Absolute visual threshold and scotopic spectral sensitivity in the tawny owl Strix aluco

  title={Absolute visual threshold and scotopic spectral sensitivity in the tawny owl Strix aluco},
  author={Graham R. Martin},
  • G. Martin
  • Published 18 August 1977
  • Biology, Medicine
  • Nature
IT has long been assumed from considerations of the behaviour of owls that the vision of these species is much more sensitive than that of man. Experimental determinations of the absolute visual sensitivity of these birds have provided evidence in support of this view, suggesting that visual sensitivity in owls is of the order of 10 to 100 times (+1.0 log10 to +2.0 log10 units) that of man1,2. Owing to calibration problems, however, these values were probably inaccurate by at least a factor of… 
Sensory capacities and the nocturnal habit of owls (Strigiformes)
Behavioural studies show that in the eye of the Tawny Owl Strix aluco both absolute visual sensitivity and maximum spatial resolution at low light levels are close to the theoretical limit dictated
An owl's eye: Schematic optics and visual performance inStrix aluco L.
  • G. Martin
  • Computer Science
    Journal of comparative physiology
  • 2004
The schematic eye ofrix aluco, a nocturnal owl species, is described and it is concluded that the essentially ‘nocturnal’ feature of the owl eye does not lie in either its light gathering power or the sensitivity of individual rod receptors.
Eye Shape and Retinal Topography in Owls (Aves: Strigiformes)
In conclusion, eye shape and retinal topography in owls vary among species and this variation is associated with different activity patterns and habitat preferences, thereby supporting similar observations in other vertebrates.
The visual fields of the tawny owl, Strix aluco L
  • G. Martin
  • Medicine, Physics
    Vision Research
  • 1984
The uniocular retinal field of Strix aluco is highly asymmetrical and the significance of the owl eye's tubular shape, its nasad asymmetry, and the possible factors influencing binocular field width are discussed.
Visual adaptations of diurnal and nocturnal raptors.
What is presently known about the eyes as well as the visual abilities of these birds, and what is known about visual pathways, are summarized.
From optics to attention: visual perception in barn owls
Orientation based saliency was demonstrated in a visual-search experiment, and higher cognitive abilities were shown when the owl’s were able to use illusory contours for object discrimination.
Form and Function in the Optical Structure of Bird Eyes
The anatomy of bird eyes has often been described in near eulogistic terms. Polyak (1957, p. 852), for example, reported that the eyes of swallows (Hirundo rustica) exhibit “extraordinary
Allometric Scaling of the Tectofugal Pathway in Birds
This work examines the allometric scaling relationships of each of these brain regions relative to the brain as a whole using conventional and phylogenetically based statistics across 113 species to speculate that if neural adaptations do exist in the avian tectofugal pathway that are correlated with behavior, they occur at a more refined level than simple volumetrics.
The Visual Ecology of Avian Photoreceptors
  • N. Hart
  • Medicine, Biology
    Progress in Retinal and Eye Research
  • 2001
The primary influence on avian retinal design appears to be the range of wavelengths available for vision, regardless of whether that range is determined by the spectral distribution of the natural illumination or the spectral transmittance of the ocular media.
Vision in birds
This chapter describes how birds acquire visual information, and in particular general principles in physiological optics, and image coding by the photoreceptors, and the way in which signals from the different types of photoreceptor are used in visual behavior.


Increment-threshold spectral sensitivity in the tawny owl (Strix aluco).
Photopic increment-threshold spectral sensitivity functions were behaviourally determined in three tawny owls, using a two-choice simultaneous discrimination procedure, and showed very close agreement.
Visual acuity in the tawny owl (Strix aluco).
Abstract Threshold visual acuity for grating stimuli was determined in two tawny owls (a totally nocturnal avian species). Extensive training was given in a runway apparatus in which stimuli were
Scotopic spectral sensitivity in a teleost fish (Scardinius erytheophthalamus) adapted to different daylengths.
When the rudd were adapted to longer daylengths their absolute sensitivity increased, and they also became relatively more sensitive at short wavelengths, which agrees with the increased short wavelength sensitivity found when the daylength was increased.
Electroretinographically determined spectral sensitivity in the tawny owl (Strix aluco).
The electroretinographic responses to single light flashes and to flickering lights were obtained in the tawny owl (Strix aluco) and indicated that the owl possesses a duplex retina.
Functionally, the owl's vision corresponds to the predominantly rod structure of its retina, and the idea that nocturnal owls have a special type of vision sensitive to infrared radiation for seeing in the woods at night is erroneous.
The results clarify the nature of the fluctuations shown by an organism in response to a stimulus, and show that at the threshold it is the stimulus which is variable, and that the properties of its variation determine the fluctuations found between response and stimulus.
The photosensitive pigments in the retinae of deep-sea fish
The significance of this type of photosensitive pigment in the vision of deep-sea fish is discussed, and an estimate is made of the depths at which deepsea fish will see daylight.
Minimum Intensities of Illumination Under Which Owls Can Find Dead Prey by Sight
The burrowing owl is more diurnal in habit than these other owls and also it lives in more open situations, so it has much less ability to see in very dim light than the other three species of owls studied.
The spectral reflectivity of the cat's tapetum measured in situ
  • R. Weale
  • Materials Science, Medicine
    The Journal of physiology
  • 1953
A determination of the in situ reflectivity of the cat's tapetum might perhaps contribute towards the elucidation of some of these problems.
Light, Colour and Vision
The translation from the original French, with the inclusion of some new material, suffers from few of the defects so frequently seen, for it reads fluently and spontaneously as if it were the original text.