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Luminance-dependence of spatial vision in budgerigars (Melopsittacus undulatus) and Bourke's parrots (Neopsephotus bourkii).

Lind, Olle LU ; Sunesson, Tony LU ; Mitkus, Mindaugas LU and Kelber, Almut LU (2012) In Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology 198. p.69-77
Abstract
Budgerigars (Melopsittacus undulatus) and Bourke's parrots (Neopsephotus bourkii) are closely related birds with different activity patterns. Budgerigars are strictly diurnal while Bourke's parrots are active in dim twilight. Earlier studies show that the intensity threshold of colour vision is similar in both species while Bourke's parrots have larger eyes with a higher density of rods than budgerigars. In this study, we investigate whether this could be an adaptation for better spatial vision in dim light. We used two alternative forced-choice experiments to determine the spatial acuity of both species at light intensities ranging from 0.08 to 73 cd/m(2). We also determined the spatial contrast sensitivity function (CSF) for bright light... (More)
Budgerigars (Melopsittacus undulatus) and Bourke's parrots (Neopsephotus bourkii) are closely related birds with different activity patterns. Budgerigars are strictly diurnal while Bourke's parrots are active in dim twilight. Earlier studies show that the intensity threshold of colour vision is similar in both species while Bourke's parrots have larger eyes with a higher density of rods than budgerigars. In this study, we investigate whether this could be an adaptation for better spatial vision in dim light. We used two alternative forced-choice experiments to determine the spatial acuity of both species at light intensities ranging from 0.08 to 73 cd/m(2). We also determined the spatial contrast sensitivity function (CSF) for bright light in Bourke's parrots and compare it to existing data for budgerigars. The spatial acuity of Bourke's parrots was found to be similar to that of budgerigars at all light levels. Also the CSF of Bourke's parrots is similar to that of budgerigars with a sensitivity peak located between 2.1 and 2.6 cycles/degree. Our findings do not support the hypothesis that Bourke's parrots have superior spatial acuity in dim light compared to budgerigars and the adaptive value of the relatively rod-rich and large eyes of Bourke's parrots remains unclear. (Less)
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type
Contribution to journal
publication status
published
subject
in
Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology
volume
198
pages
69 - 77
publisher
Springer
external identifiers
  • wos:000301844000007
  • pmid:22001888
  • scopus:84855287263
ISSN
1432-1351
DOI
10.1007/s00359-011-0689-7
language
English
LU publication?
yes
id
e758a063-843a-47a4-8584-6a846de26218 (old id 2200469)
date added to LUP
2011-11-09 13:58:27
date last changed
2017-10-01 04:07:53
@article{e758a063-843a-47a4-8584-6a846de26218,
  abstract     = {Budgerigars (Melopsittacus undulatus) and Bourke's parrots (Neopsephotus bourkii) are closely related birds with different activity patterns. Budgerigars are strictly diurnal while Bourke's parrots are active in dim twilight. Earlier studies show that the intensity threshold of colour vision is similar in both species while Bourke's parrots have larger eyes with a higher density of rods than budgerigars. In this study, we investigate whether this could be an adaptation for better spatial vision in dim light. We used two alternative forced-choice experiments to determine the spatial acuity of both species at light intensities ranging from 0.08 to 73 cd/m(2). We also determined the spatial contrast sensitivity function (CSF) for bright light in Bourke's parrots and compare it to existing data for budgerigars. The spatial acuity of Bourke's parrots was found to be similar to that of budgerigars at all light levels. Also the CSF of Bourke's parrots is similar to that of budgerigars with a sensitivity peak located between 2.1 and 2.6 cycles/degree. Our findings do not support the hypothesis that Bourke's parrots have superior spatial acuity in dim light compared to budgerigars and the adaptive value of the relatively rod-rich and large eyes of Bourke's parrots remains unclear.},
  author       = {Lind, Olle and Sunesson, Tony and Mitkus, Mindaugas and Kelber, Almut},
  issn         = {1432-1351},
  language     = {eng},
  pages        = {69--77},
  publisher    = {Springer},
  series       = {Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology},
  title        = {Luminance-dependence of spatial vision in budgerigars (Melopsittacus undulatus) and Bourke's parrots (Neopsephotus bourkii).},
  url          = {http://dx.doi.org/10.1007/s00359-011-0689-7},
  volume       = {198},
  year         = {2012},
}