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Seasonal variation in patch use in a tropical African environment

Molokwu, Mary Ngozi; Olsson, Ola LU ; Nilsson, Jan-Åke LU and Ottosson, Ulf LU (2008) In Oikos 117(6). p.892-898
Abstract
We used giving-up densities (GUD) to study patch use decisions of small granivorous passerines throughout the year. We measured GUDs continuously in four sites for a period of 9-10 months per year during 2004 and 2005 in a savannah area in Jos, central Nigeria. The study thus covered a period from the middle of the dry season, through the wet season to the beginning of the next dry season in each year. We placed experimental food patches in both open areas and in cover to investigate possible effects of predation risk and thermal hazard on the foraging behavior of the birds. We found a difference in GUDs between the microhabitats, with a consistently lower GUD in cover throughout the year and for the two years. During both years GUDs... (More)
We used giving-up densities (GUD) to study patch use decisions of small granivorous passerines throughout the year. We measured GUDs continuously in four sites for a period of 9-10 months per year during 2004 and 2005 in a savannah area in Jos, central Nigeria. The study thus covered a period from the middle of the dry season, through the wet season to the beginning of the next dry season in each year. We placed experimental food patches in both open areas and in cover to investigate possible effects of predation risk and thermal hazard on the foraging behavior of the birds. We found a difference in GUDs between the microhabitats, with a consistently lower GUD in cover throughout the year and for the two years. During both years GUDs followed a pattern coinciding with the seasonal change in local seed availability. An initial decline in GUDs late in the dry season was followed by a steady increase during and after the rains. A similar trend in GUDs observed for both years supports the conclusion that GUDs measure the feeding birds' assessment of environmental quality, possibly in combination with other factors changing predictably during the year. We conclude that food abundance may act with other environmental and ecological factors to affect foraging decisions throughout the year. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Oikos
volume
117
issue
6
pages
892 - 898
publisher
Wiley-Blackwell
external identifiers
  • wos:000256839300010
  • scopus:45749101219
ISSN
1600-0706
DOI
10.1111/j.0030-1299.2008.16549.x
language
English
LU publication?
yes
id
e443c004-8e1e-4a2c-8337-5c6075abb42b (old id 1190551)
date added to LUP
2008-09-08 10:04:20
date last changed
2017-05-28 03:46:01
@article{e443c004-8e1e-4a2c-8337-5c6075abb42b,
  abstract     = {We used giving-up densities (GUD) to study patch use decisions of small granivorous passerines throughout the year. We measured GUDs continuously in four sites for a period of 9-10 months per year during 2004 and 2005 in a savannah area in Jos, central Nigeria. The study thus covered a period from the middle of the dry season, through the wet season to the beginning of the next dry season in each year. We placed experimental food patches in both open areas and in cover to investigate possible effects of predation risk and thermal hazard on the foraging behavior of the birds. We found a difference in GUDs between the microhabitats, with a consistently lower GUD in cover throughout the year and for the two years. During both years GUDs followed a pattern coinciding with the seasonal change in local seed availability. An initial decline in GUDs late in the dry season was followed by a steady increase during and after the rains. A similar trend in GUDs observed for both years supports the conclusion that GUDs measure the feeding birds' assessment of environmental quality, possibly in combination with other factors changing predictably during the year. We conclude that food abundance may act with other environmental and ecological factors to affect foraging decisions throughout the year.},
  author       = {Molokwu, Mary Ngozi and Olsson, Ola and Nilsson, Jan-Åke and Ottosson, Ulf},
  issn         = {1600-0706},
  language     = {eng},
  number       = {6},
  pages        = {892--898},
  publisher    = {Wiley-Blackwell},
  series       = {Oikos},
  title        = {Seasonal variation in patch use in a tropical African environment},
  url          = {http://dx.doi.org/10.1111/j.0030-1299.2008.16549.x},
  volume       = {117},
  year         = {2008},
}