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Visual configuration of two species of Falconidae with different foraging ecologies

Potier, Simon LU ; Bonadonna, Francesco ; Martin, Graham R. ; Isard, Pierre François ; Dulaurent, Thomas ; Mentek, Marielle and Duriez, Olivier (2017) In Ibis 160. p.54-61
Abstract
Significant interspecific differences in avian vision occur, even in congeneric species, and these have been correlated with differences in the perceptual challenges associated with foraging. Although diurnal raptors are assumed to be mainly visually guided in their foraging, they differ markedly in their foraging tactics and this may result in different visual demands. Among the Falconidae (Falconiformes), most falcons forage mainly on the wing for highly mobile prey, whereas caracaras forage on the ground for carrion and insects. We assessed whether Saker Falcon Falco cherrug and Southern Caracara Caracara plancus differ in their visual abilities by determining the visual fields and foveal characteristics of both species. Using an... (More)
Significant interspecific differences in avian vision occur, even in congeneric species, and these have been correlated with differences in the perceptual challenges associated with foraging. Although diurnal raptors are assumed to be mainly visually guided in their foraging, they differ markedly in their foraging tactics and this may result in different visual demands. Among the Falconidae (Falconiformes), most falcons forage mainly on the wing for highly mobile prey, whereas caracaras forage on the ground for carrion and insects. We assessed whether Saker Falcon Falco cherrug and Southern Caracara Caracara plancus differ in their visual abilities by determining the visual fields and foveal characteristics of both species. Using an ophthalmoscopic reflex technique, we found a higher degree of binocular overlap in the caracaras than in the falcons. The high binocular overlap (47 degrees) of the Southern Caracara may facilitate object manipulation (e.g. moving rocks) when foraging. We used an ultra-high resolution spectral-domain optical coherence tomography to determine foveal characteristics. We found two foveas (depressions in the retina where high visual resolution is expected) in the falcons (one central and one temporal) but only a central fovea in the caracaras. The presence of a shallower temporal fovea in Saker Falcons may help to fixate visually upon a highly mobile prey item during pursuit. We conclude that these differences in visual field configurations and foveal characteristics reflect different foraging demands, suggesting that the extraction of visual information is finely tuned to the demands of their foraging tactics. (Less)
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author
; ; ; ; ; and
publishing date
type
Contribution to journal
publication status
published
subject
keywords
foraging, Fovea, prey capture, Saker Falcon, Southern Caracara, visual field
in
Ibis
volume
160
pages
54 - 61
publisher
Wiley-Blackwell
external identifiers
  • scopus:85029234888
ISSN
0019-1019
DOI
10.1111/ibi.12528
language
English
LU publication?
no
id
87bc9979-c1b4-45cd-ba15-6f066b7405bc
date added to LUP
2018-05-09 14:22:01
date last changed
2020-09-23 07:02:47
@article{87bc9979-c1b4-45cd-ba15-6f066b7405bc,
  abstract     = {Significant interspecific differences in avian vision occur, even in congeneric species, and these have been correlated with differences in the perceptual challenges associated with foraging. Although diurnal raptors are assumed to be mainly visually guided in their foraging, they differ markedly in their foraging tactics and this may result in different visual demands. Among the Falconidae (Falconiformes), most falcons forage mainly on the wing for highly mobile prey, whereas caracaras forage on the ground for carrion and insects. We assessed whether Saker Falcon Falco cherrug and Southern Caracara Caracara plancus differ in their visual abilities by determining the visual fields and foveal characteristics of both species. Using an ophthalmoscopic reflex technique, we found a higher degree of binocular overlap in the caracaras than in the falcons. The high binocular overlap (47 degrees) of the Southern Caracara may facilitate object manipulation (e.g. moving rocks) when foraging. We used an ultra-high resolution spectral-domain optical coherence tomography to determine foveal characteristics. We found two foveas (depressions in the retina where high visual resolution is expected) in the falcons (one central and one temporal) but only a central fovea in the caracaras. The presence of a shallower temporal fovea in Saker Falcons may help to fixate visually upon a highly mobile prey item during pursuit. We conclude that these differences in visual field configurations and foveal characteristics reflect different foraging demands, suggesting that the extraction of visual information is finely tuned to the demands of their foraging tactics.},
  author       = {Potier, Simon and Bonadonna, Francesco and Martin, Graham R. and Isard, Pierre François and Dulaurent, Thomas and Mentek, Marielle and Duriez, Olivier},
  issn         = {0019-1019},
  language     = {eng},
  pages        = {54--61},
  publisher    = {Wiley-Blackwell},
  series       = {Ibis},
  title        = {Visual configuration of two species of Falconidae with different foraging ecologies},
  url          = {http://dx.doi.org/10.1111/ibi.12528},
  doi          = {10.1111/ibi.12528},
  volume       = {160},
  year         = {2017},
}