The effects of predation risk on the use of social foraging tactics

Z. Barta, A. Likér, Ferenc Mónus

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

The effects of predation on the use of social foraging tactics, such as producing and scrounging, are poorly known in animals. On the one hand, recent theoretical models predict increased use of scrounging with increasing predation risk, when scroungers seeking feeding opportunities also have a higher chance of detecting predators. On the other hand, there may be no relation between tactic use and predation when antipredator vigilance is not compatible with scanning flockmates. We investigated experimentally the effects of predation risk on social foraging tactic use in tree sparrows, Passer montanus. We manipulated predation risk in the field by changing the distance between shelter and a feeder. Birds visited the feeder in smaller flocks, spent less time on it and were somewhat more vigilant far from shelter than close to it. Increased predation risk strongly affected the social foraging tactic used: birds used the scrounger tactic 30% more often far from cover than close to it. Between-flock variability in scrounging frequency was not related to the average vigilance level of the flock members, and within-flock variability in the use of scrounging was negatively related to the vigilance of birds. Our results suggest that in tree sparrows, the increased frequency of scrounging during high predation risk cannot simply be explained by an additional advantage of increasing antipredator vigilance. We propose alternative mechanisms (e.g. increased stochasticity in food supply, and that riskier places are used by individuals with lower reserves) that may explain increased scrounging when animals forage under high predation risk.

Original languageEnglish
Pages (from-to)301-308
Number of pages8
JournalAnimal Behaviour
Volume67
Issue number2
DOIs
Publication statusPublished - Feb 2004

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predation risk
vigilance
foraging
predation
Passer montanus
flocks
bird
shelter
birds
animal
stochasticity
food supply
forage
effect
predator
animals
predators

ASJC Scopus subject areas

  • Animal Science and Zoology
  • Ecology, Evolution, Behavior and Systematics

Cite this

The effects of predation risk on the use of social foraging tactics. / Barta, Z.; Likér, A.; Mónus, Ferenc.

In: Animal Behaviour, Vol. 67, No. 2, 02.2004, p. 301-308.

Research output: Contribution to journalArticle

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