Induced homosexual behaviour in male house finches (carpodacus mexicanus): The “prisoner effect”

K. J. McGraw, G. E. Hill

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


We observed homosexual behaviour within a captive flock of male house finches (Carpodacus mexicanus) that was physically isolated from females for the duration of a breeding season. Male-male begging, allofeeding and copulation attempts were linked to social dominance rank within the group, as subordinate males begged from, were fed by, and attempted to copulate with dominant males. Levels of circulating testosterone were not significantly related to inter-male behaviour. Along with the assertion of dominance, we presume that the regulation of sociosexual tension is another potential function of the male homosexual behaviour observed in this study.

Original languageEnglish (US)
Pages (from-to)197-201
Number of pages5
JournalEthology Ecology and Evolution
Issue number2
StatePublished - Apr 1 1999
Externally publishedYes


  • Aggression
  • Allofeeding
  • Carpodacus mexicanus
  • Copulatory behaviour
  • Homosexuality
  • House finch
  • Social dominance
  • Testosterone

ASJC Scopus subject areas

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


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