Behavioral Ecology and Sociobiology

, Volume 38, Issue 6, pp 425–430

The high frequency of extra-pair paternity in tree swallows is not an artifact of nestboxes

  • C. A. Barber
  • Raleigh J. Robertson
  • Peter T. Boag

DOI: 10.1007/s002650050260

Cite this article as:
Barber, C., Robertson, R. & Boag, P. Behav Ecol Sociobiol (1996) 38: 425. doi:10.1007/s002650050260

Abstract

A common criticism of nestbox studies is one of creating artificial nesting conditions and breeding behavior different from what would be seen under natural conditions. We assessed the frequency of extra-pair paternity (percentage of broods with at least one extra-pair young) in 25 families of tree swallows (Tachycineta bicolor) nesting in natural cavities and compared it to that in a nestbox population. We found that 84% of females nesting in natural cavities obtained fertilizations from extra-pair males. These extra-pair males fathered 69% of all nestlings. Studies of tree swallows breeding in nestboxes have shown that 50–87% of broods contained extra-pair young, with extra-pair males fathering 38–53% of all the young. In broods with extra-pair paternity, natural cavities contained a significantly greater proportion of extra-pair young than did nestboxes. Despite differences in nesting habitat and female age structure, the frequency of extra-pair paternity did not differ significantly between the natural-cavity and nestbox populations. Therefore, the presence of extra-pair paternity in tree swallows is not an artifact of nestboxes or of artificial nesting conditions.

Key words Cavity nestersExtra-pair paternityExtra-pair youngNestboxesTachycineta bicolor

Copyright information

© Springer-Verlag Berlin Heidelberg 1996

Authors and Affiliations

  • C. A. Barber
    • 1
  • Raleigh J. Robertson
    • 1
  • Peter T. Boag
    • 1
  1. 1.Department of Biology, Queen’s University, Kingston, Ontario, K7L 3N6, CanadaCA