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Response of predators to prey abundance: separating the effects of prey density and patch size

Wellenreuther, Maren LU and Connell, Sean Duncan (2002) In Journal of Experimental Marine Biology and Ecology 273(1). p.61-71
Abstract
We tested the relative and combined effects of prey density and patch size on the functional response (number of attacks per unit time and duration of attacks) of a predatory reef fish (Cheilodactylus nigripes (Richardson)) to their invertebrate prey. Fish attacked prey at a greater rate and for longer time in large than small patches of prey, but large patches had naturally greater densities of prey. We isolated the effects of patch size and prey density by reducing the density of prey in larger patches to equal that of small patches; thereby controlling for prey density. We found that the intensity at which fish attacked prey (combination of attack rate and duration) was primarily a response to prey density rather than the size of patch... (More)
We tested the relative and combined effects of prey density and patch size on the functional response (number of attacks per unit time and duration of attacks) of a predatory reef fish (Cheilodactylus nigripes (Richardson)) to their invertebrate prey. Fish attacked prey at a greater rate and for longer time in large than small patches of prey, but large patches had naturally greater densities of prey. We isolated the effects of patch size and prey density by reducing the density of prey in larger patches to equal that of small patches; thereby controlling for prey density. We found that the intensity at which fish attacked prey (combination of attack rate and duration) was primarily a response to prey density rather than the size of patch they occupied. However, there was evidence that fish spent more time foraging in larger than smaller patches independent of prey density; presumably because of the greater total number of prey available. These experimental observations suggest that fish can distinguish between different notions of prey abundance in ways that enhance their rate of consumption. Although fish may feed in a density dependent manner, a critical issue is whether their rate of consumption outstrips the rate of increase in prey abundance to cause density dependent mortality of prey. (Less)
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author
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Experimental Marine Biology and Ecology
volume
273
issue
1
pages
61 - 71
publisher
Elsevier
external identifiers
  • scopus:0037014463
ISSN
0022-0981
DOI
10.1016/S0022-0981(02)00145-4
language
English
LU publication?
no
id
2de8358d-b27f-4fab-a185-354fb69c966b (old id 1963519)
date added to LUP
2011-05-19 08:46:44
date last changed
2017-10-01 04:35:09
@article{2de8358d-b27f-4fab-a185-354fb69c966b,
  abstract     = {We tested the relative and combined effects of prey density and patch size on the functional response (number of attacks per unit time and duration of attacks) of a predatory reef fish (Cheilodactylus nigripes (Richardson)) to their invertebrate prey. Fish attacked prey at a greater rate and for longer time in large than small patches of prey, but large patches had naturally greater densities of prey. We isolated the effects of patch size and prey density by reducing the density of prey in larger patches to equal that of small patches; thereby controlling for prey density. We found that the intensity at which fish attacked prey (combination of attack rate and duration) was primarily a response to prey density rather than the size of patch they occupied. However, there was evidence that fish spent more time foraging in larger than smaller patches independent of prey density; presumably because of the greater total number of prey available. These experimental observations suggest that fish can distinguish between different notions of prey abundance in ways that enhance their rate of consumption. Although fish may feed in a density dependent manner, a critical issue is whether their rate of consumption outstrips the rate of increase in prey abundance to cause density dependent mortality of prey.},
  author       = {Wellenreuther, Maren and Connell, Sean Duncan},
  issn         = {0022-0981},
  language     = {eng},
  number       = {1},
  pages        = {61--71},
  publisher    = {Elsevier},
  series       = {Journal of Experimental Marine Biology and Ecology},
  title        = {Response of predators to prey abundance: separating the effects of prey density and patch size},
  url          = {http://dx.doi.org/10.1016/S0022-0981(02)00145-4},
  volume       = {273},
  year         = {2002},
}