Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Extra-pair copulation and sperm competition in the zebra finch


Most birds are monogamous, but recent studies have shown that extra-pair copulations (EPCs) occur frequently1,2 despite a range of paternity guards, including mate-guarding and frequent copulation1. Although EPCs are known to result in extra-pair paternity3–5, there are no previous quantitative estimates of the success of EPCs in fertilizing eggs. We present here estimates of the likelihood of success of extra-pair copulations in a monogamous passerine, the zebra finch Poephila guttata. We show that (1) EPCs occurring under semi-natural conditions in captivity result in extra-pair paternity, (2) sperm from the last male to mate has precedence over previous matings: a single EPC occurring last is disproportionately successful in fertilizing eggs, but EPCs followed by further pair copulations have a low probability of success. These results have important implications for sexual selection theory.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout


  1. Birkhead, T. R., Atkin, L. & Moller, A. P. Behaviour 101, 101–138 (1987).

    Article  Google Scholar 

  2. McKinney, F., Cheng, K. M. & Bruggers, D. in Sperm Competition and the evolution of animal mating systems (ed. Smith, R. L.) 523–545 (Academic, New York, 1984).

    Book  Google Scholar 

  3. Westneat, D. Anim. Behav. 35, 865–876 (1987).

    Article  Google Scholar 

  4. Westneat, D. Anim. Behav. 35, 877–886 (1987).

    Article  Google Scholar 

  5. Burke, T. & Bruford, M. W. Nature 327, 149–152 (1987).

    Article  ADS  CAS  Google Scholar 

  6. Parker, G. A. Biol. Rev. 45, 525–567 (1970).

    Article  Google Scholar 

  7. Compton, M. M., van Krey, H. P. & Siegel, P. B. Poult. Sci. 57, 1696–1700 (1978).

    Article  CAS  Google Scholar 

  8. Birkhead, T. R. Adv. Stud. Behav. 18, 35–72 (1988).

    Article  Google Scholar 

  9. Moller, A. P. Behav. Ecol. Sociobiol. 17, 401–408 (1985).

    Article  Google Scholar 

  10. Birkhead, T. R., Clarkson, K. & Zann, R. Anim. Behav. (in the press).

  11. Frith, H. J. & Tilt, R. A. Emu 59, 289–295 1959).

    Article  Google Scholar 

  12. Lanier, D. L., Estep, D. Q. & Dewsbury, D. A. J. comp. Physiol. Psychol. 93, 781–792 (1979).

    Article  Google Scholar 

  13. Birkhead, T. R. Anim. Behav. 27, 866–874 (1979).

    Article  Google Scholar 

  14. Martin, P. A., Reimers, T. J., Lodge, J. R. & Dzuik, P. K. J. Reprod. Fert. 39, 251–258 (1974).

    Article  CAS  Google Scholar 

  15. Payne, L. F. & Kahrs, A. J. Poult. Sci. 40, 1598–1604 (1961).

    Article  Google Scholar 

  16. Sims, M. E., Ball, G. F. & Cheng, M. F. Condor. 89, 112–116 (1987).

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and Permissions

About this article

Cite this article

Birkhead, T., Pellatt, J. & Hunter, F. Extra-pair copulation and sperm competition in the zebra finch. Nature 334, 60–62 (1988).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing