Advanced

Interspecific competition and predation: relative effects on foragers and their densities

Nilsson, Erika LU ; Persson, Anders LU and Nilsson, Anders LU (2010) In Behavioral Ecology and Sociobiology 64(5). p.729-736
Abstract
Predation and competition are both strong structuring forces in community dynamics, but their relative importance is disputed. In a laboratory experiment, we evaluated the relative importance of competition and predation from juvenile and adult brown trout, respectively, on foraging performance of groups of three stone loaches. We observed loach consumption rate, time spent inactive, and aggressive interactions between juvenile trout and loach in artificial stream sections. The controlled experiments were complemented by examining stone loach population densities in natural systems as functions of juvenile and adult trout. In the laboratory experiments, increasing numbers of competitors decreased prey availability, which ultimately led to... (More)
Predation and competition are both strong structuring forces in community dynamics, but their relative importance is disputed. In a laboratory experiment, we evaluated the relative importance of competition and predation from juvenile and adult brown trout, respectively, on foraging performance of groups of three stone loaches. We observed loach consumption rate, time spent inactive, and aggressive interactions between juvenile trout and loach in artificial stream sections. The controlled experiments were complemented by examining stone loach population densities in natural systems as functions of juvenile and adult trout. In the laboratory experiments, increasing numbers of competitors decreased prey availability, which ultimately led to lower consumption rates for loach. Loach responded to predation risk by increasing time being inactive, thereby decreasing consumption rates. However, there were no effects of juvenile trout competitors on loach consumption rates in treatments with adult trout presence, suggesting no additive effect of predation and competition on loach foraging success. Partial regressions of loach and trout densities in natural streams revealed a positive relationship between juvenile trout and loach, and a negative relationship between adult trout and loach. Our laboratory and field data thus suggest that predation is a limiting factor for loach success, and predator presence could mediate species coexistence at high interspecific densities. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Salmo trutta, barbatula, Barbatula, Fish, Predation, Foraging, Interspecific competition
in
Behavioral Ecology and Sociobiology
volume
64
issue
5
pages
729 - 736
publisher
Springer
external identifiers
  • wos:000275631100003
  • scopus:77950533716
ISSN
1432-0762
DOI
10.1007/s00265-009-0890-7
language
English
LU publication?
yes
id
efa93cce-f98b-4f3f-9030-54a34ec396d7 (old id 1588136)
date added to LUP
2010-04-22 10:37:32
date last changed
2018-05-29 09:48:04
@article{efa93cce-f98b-4f3f-9030-54a34ec396d7,
  abstract     = {Predation and competition are both strong structuring forces in community dynamics, but their relative importance is disputed. In a laboratory experiment, we evaluated the relative importance of competition and predation from juvenile and adult brown trout, respectively, on foraging performance of groups of three stone loaches. We observed loach consumption rate, time spent inactive, and aggressive interactions between juvenile trout and loach in artificial stream sections. The controlled experiments were complemented by examining stone loach population densities in natural systems as functions of juvenile and adult trout. In the laboratory experiments, increasing numbers of competitors decreased prey availability, which ultimately led to lower consumption rates for loach. Loach responded to predation risk by increasing time being inactive, thereby decreasing consumption rates. However, there were no effects of juvenile trout competitors on loach consumption rates in treatments with adult trout presence, suggesting no additive effect of predation and competition on loach foraging success. Partial regressions of loach and trout densities in natural streams revealed a positive relationship between juvenile trout and loach, and a negative relationship between adult trout and loach. Our laboratory and field data thus suggest that predation is a limiting factor for loach success, and predator presence could mediate species coexistence at high interspecific densities.},
  author       = {Nilsson, Erika and Persson, Anders and Nilsson, Anders},
  issn         = {1432-0762},
  keyword      = {Salmo trutta,barbatula,Barbatula,Fish,Predation,Foraging,Interspecific competition},
  language     = {eng},
  number       = {5},
  pages        = {729--736},
  publisher    = {Springer},
  series       = {Behavioral Ecology and Sociobiology},
  title        = {Interspecific competition and predation: relative effects on foragers and their densities},
  url          = {http://dx.doi.org/10.1007/s00265-009-0890-7},
  volume       = {64},
  year         = {2010},
}