Experimental manipulation of intraclutch variation in the great reed warbler shows no effect on rejection of parasitic eggs

Zsolt Karcza, C. Moskát, Michael I. Cherry, T. Kisbenedek

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

In the continuing arms race between hosts and brood parasites, hosts are expected to reduce variation in the appearance of their own eggs within clutches, as it facilitates recognition of parasitic eggs. At the same time, by increasing interclutch variation, hosts should make it more difficult for parasites to evolve perfectly mimetic eggs. In this study, we experimentally manipulated intraclutch variation in the great reed warbler, Acrocephalus arundinaceus, in Hungary, where this species is heavily (c. 64%) parasitized by the common cuckoo, Cuculus canorus. We placed artificial cuckoo eggs, which appeared moderately mimetic to humans, in two groups of nests; in one group we increased variability of egg appearance within clutches by exchanging host eggs among nests. These clutches showed a significantly higher intraclutch variability than natural clutches, which we used as a control group. Our results indicate that it has no effect on rejection behaviour in this species, neither when variation was increased experimentally, nor within the natural range of variation displayed by our population. We suggest that when parasitism is high, selection for reduced intraclutch variation may be less important than frequency-dependent selection for increased variation between individuals within a host population.

Original languageEnglish
Pages (from-to)15-22
Number of pages8
JournalEthology
Volume109
Issue number1
DOIs
Publication statusPublished - Jan 1 2003

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Songbirds
Eggs
egg
Cuculus canorus
Parasites
nests
nest
parasite
parasites
Hungary
arms race
Population
individual variation
Ovum
parasitism
Rejection (Psychology)
effect
reed
Acrocephalus arundinaceus
Control Groups

ASJC Scopus subject areas

  • Animal Science and Zoology
  • Behavioral Neuroscience

Cite this

Experimental manipulation of intraclutch variation in the great reed warbler shows no effect on rejection of parasitic eggs. / Karcza, Zsolt; Moskát, C.; Cherry, Michael I.; Kisbenedek, T.

In: Ethology, Vol. 109, No. 1, 01.01.2003, p. 15-22.

Research output: Contribution to journalArticle

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