Paternal expenditure is related to brood sex ratio in polygynous great reed warblers

Isao Nishiumi, Satoshi Yamagishi, Hiromi Maekawa, Chikashi Shimoda

Research output: Contribution to journalArticlepeer-review

54 Citations (Scopus)


In many polygynous animals, parents invest more heavily in individual sons than in daughters. However, it is unclear if these differences in investment are a consequence of sex differences in the demand of offspring related to sexual size dimorphism or a consequence of parental manipulation. Here, we report on parental food delivery frequency in relation to brood size and brood sex ratio in a wild population of polygynous great reed warblers Acrocephalus arundinaceus. We used the polymorphic microsatellite loci on the Z chromosome to sex chicks. We found that paternal feeding frequency (times/h per nest) increased not with brood size, but with the proportion of males in the brood, although the demand per nest was more closely related to brood size than to brood sex ratio. Additionally, the increase in rate of paternal feeding frequency in relation to the brood sex ratio was much higher than the increase in rate of nestling food demands. Maternal feeding frequency was independent of both brood size and brood sex ratio. These results strongly suggest that fathers preferentially invest in their sons. We propose that parents can afford sex-biased parental care in animals in which food provisioning is enough for all offspring to survive.

Original languageEnglish
Pages (from-to)211-217
Number of pages7
JournalBehavioral Ecology and Sociobiology
Issue number4
Publication statusPublished - 1996
Externally publishedYes

All Science Journal Classification (ASJC) codes

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


Dive into the research topics of 'Paternal expenditure is related to brood sex ratio in polygynous great reed warblers'. Together they form a unique fingerprint.

Cite this