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Environmental Conditions and Intraspecific Interference: Unexpected Effects of Turbidity on Pike (Esox lucius) Foraging

Nilsson, Anders LU ; Jacobsen, Lene; Berg, Soren and Skov, Christian (2009) In Ethology 115(1). p.33-38
Abstract
Interference among predators decreases per capita foraging rates and has implications for both community dynamics and top-down trophic processes. Interference originates from behavioural interactions among foragers, and these behaviours could be affected by environmental conditions. In experiments on pike foraging alone or among conspecifics in different levels of water turbidity, we expected high turbidity to decrease the perceived risk of intraspecific interactions among pike, and thereby decrease the strength of interference, as turbidity would decrease the visual contact between individuals and act as a refuge from behavioural interactions. The results show that this is not the case, but suggest that interference is induced instead of... (More)
Interference among predators decreases per capita foraging rates and has implications for both community dynamics and top-down trophic processes. Interference originates from behavioural interactions among foragers, and these behaviours could be affected by environmental conditions. In experiments on pike foraging alone or among conspecifics in different levels of water turbidity, we expected high turbidity to decrease the perceived risk of intraspecific interactions among pike, and thereby decrease the strength of interference, as turbidity would decrease the visual contact between individuals and act as a refuge from behavioural interactions. The results show that this is not the case, but suggest that interference is induced instead of reduced in high turbidity. Per capita foraging rates do not differ between pike foraging alone or in groups in our clear and moderately turbid treatments, indicating no effect of interference. As high turbidity enhances prey consumption for pike individuals foraging alone, but does not have this effect for pike in groups, high turbidity induces the relative interference effect. We suggest that future evaluations of the stabilizing effects of interference on community dynamics and its reduction of predation impact on top-down trophic cascades should consider potential unexpected effects of environmental conditions. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Ethology
volume
115
issue
1
pages
33 - 38
publisher
Wiley-Blackwell
external identifiers
  • wos:000261836000005
  • scopus:58149083775
ISSN
1439-0310
DOI
10.1111/j.1439-0310.2008.01578.x
language
English
LU publication?
yes
id
59ce3578-39bc-434b-bbed-5add3764fa5d (old id 1313664)
date added to LUP
2009-03-06 15:29:02
date last changed
2017-01-01 06:04:42
@article{59ce3578-39bc-434b-bbed-5add3764fa5d,
  abstract     = {Interference among predators decreases per capita foraging rates and has implications for both community dynamics and top-down trophic processes. Interference originates from behavioural interactions among foragers, and these behaviours could be affected by environmental conditions. In experiments on pike foraging alone or among conspecifics in different levels of water turbidity, we expected high turbidity to decrease the perceived risk of intraspecific interactions among pike, and thereby decrease the strength of interference, as turbidity would decrease the visual contact between individuals and act as a refuge from behavioural interactions. The results show that this is not the case, but suggest that interference is induced instead of reduced in high turbidity. Per capita foraging rates do not differ between pike foraging alone or in groups in our clear and moderately turbid treatments, indicating no effect of interference. As high turbidity enhances prey consumption for pike individuals foraging alone, but does not have this effect for pike in groups, high turbidity induces the relative interference effect. We suggest that future evaluations of the stabilizing effects of interference on community dynamics and its reduction of predation impact on top-down trophic cascades should consider potential unexpected effects of environmental conditions.},
  author       = {Nilsson, Anders and Jacobsen, Lene and Berg, Soren and Skov, Christian},
  issn         = {1439-0310},
  language     = {eng},
  number       = {1},
  pages        = {33--38},
  publisher    = {Wiley-Blackwell},
  series       = {Ethology},
  title        = {Environmental Conditions and Intraspecific Interference: Unexpected Effects of Turbidity on Pike (Esox lucius) Foraging},
  url          = {http://dx.doi.org/10.1111/j.1439-0310.2008.01578.x},
  volume       = {115},
  year         = {2009},
}