Your PDF has successfully downloaded.

You may be interested in finding more content on these topics:


You are not currently logged in.

Access JSTOR through your library or other institution:


Log in through your institution.

Journal Article

Direct Benefits and Genetic Costs of Extrapair Paternity for Female American Crows (Corvus brachyrhynchos)

Andrea K. Townsend, Anne B. Clark and Kevin J. McGowan
The American Naturalist
Vol. 175, No. 1 (January 2010), pp. E1-E9
DOI: 10.1086/648553
Stable URL:
Page Count: 9
Were these topics helpful?
See somethings inaccurate? Let us know!

Select the topics that are inaccurate.

  • Download PDF
  • Add to My Lists
  • Cite this Item
We're having trouble loading this content. Download PDF instead.


Abstract: The idea that extrapair paternity (EPP) in birds is part of a mixed reproductive strategy driven primarily by females is controversial. In cooperatively breeding American crows, we compared predictions of four female benefits hypotheses—the genetic diversity, good genes, genetic compatibility, and direct benefits hypotheses—to our predictions if EPP was primarily male driven. We found that genetically diverse broods were not more successful, extrapair young were not in better condition and did not have a higher survival probability, and, contrary to prediction, offspring sired by within‐group extrapair males were more inbred than within‐pair offspring. There was evidence of direct benefits, however: provisioning rate and number of surviving offspring were higher in groups containing within‐group extrapair sires. Females therefore derived no apparent benefits from extragroup extrapair males but both direct benefits and genetic costs from within‐group extrapair males. We suggest that males and females both influence the distribution of EPP in this system.

Notes and References

This item contains 36 references.

Literature Cited
  • ['Akcay, E., and J. Roughgarden. 2007. Extra‐pair paternity in birds: review of the genetic benefits. Evolutionary Ecology Research 9:855–868.']
  • ['Alexander, R. D. 1974. The evolution of social behavior. Annual Review of Ecology and Systematics 5:325–383.']
  • ['Amos, W., J. W. Wilmer, K. Fullard, T. M. Burg, J. P. Croxall, D. Bloch, and T. Coulson. 2001. The influence of parental relatedness on reproductive success. Proceedings of the Royal Society B: Biological Sciences 268:2021–2027.']
  • ['Arnqvist, G., and M. Kirkpatrick. 2005. The evolution of infidelity in socially monogamous passerines: the strength of direct and indirect selection on extrapair copulation behavior in females. American Naturalist 165(suppl.):S26–S37.']
  • ['———. 2007. The evolution of infidelity in socially monogamous passerines: a response to Griffith. American Naturalist 169:282–283.']
  • ['Bouwman, K. M., T. Burke, and J. Komdeur. 2006. How female reed buntings benefit from extra‐pair mating behaviour: testing hypotheses through patterns of paternity in sequential broods. Molecular Ecology 15:2589–2600.']
  • ['Caffrey, C. 1999. Feeding rates and individual contributions to feeding at nests in cooperatively breeding western American crows. Auk 116:836–841.']
  • ['Charlesworth, D., and B. Charlesworth. 1987. Inbreeding depression and its evolutionary consequences. Annual Review of Ecology and Systematics 18:237–268.']
  • ['Clark, A. B., D. A. Robinson, and K. J. McGowan. 2006. Effects of West Nile virus mortality on social structure of an American crow (Corvus brachyrhynchos) population in New York state. Ornithological Monographs 60:65–78.']
  • ['Cockburn, A. 2004. Mating systems and sexual conflict. Pages 81–101 in W. D. Koenig and J. L. Dickinson, eds. Ecology and evolution of cooperative breeding in birds. Cambridge University Press, Cambridge.']
  • ['Eliassen, S., and H. Kokko. 2008. Current analyses do not resolve whether extra‐pair paternity is male or female driven. Behavioral Ecology and Sociobiology 62:1795–1804.']
  • ['Fossoy, F., A. Johnsen, and J. T. Lifjeld. 2008. Multiple genetic benefits of female promiscuity in a socially monogamous passerine. Evolution 62:145–156.']
  • ['Fridolfsson, A. K., and H. Ellegren. 1999. A simple and universal method for molecular sexing of non‐ratite birds. Journal of Avian Biology 30:116–121.']
  • ['Gowaty, P. A., and N. Buschhaus. 1998. Ultimate causation of aggressive and forced copulation in birds: female resistance, the CODE hypothesis, and social monogamy. American Zoologist 38:207–225.']
  • ['Gray, E. M. 1997. Female red‐winged blackbirds accrue material benefits from copulating with extra‐pair males. Animal Behaviour 53:625–639.']
  • ['Griffith, S. C. 2007. The evolution of infidelity in socially monogamous passerines: neglected components of direct and indirect selection. American Naturalist 169:274–281.']
  • ['Griffith, S. C., I. P. Owens, and K. A. Thuman. 2002. Extra pair paternity in birds: a review of interspecific variation and adaptive function. Molecular Ecology 11:2195–2212.']
  • ['Kalinowski, S. T., M. L. Taper, and T. C. Marshall. 2007. Revising how the computer program CERVUS accommodates genotyping error increases success in paternity assignment. Molecular Ecology 16:1099–1106.']
  • ['Kempenaers, B. 2007. Mate choice and genetic quality: a review of the heterozygosity theory. Pages 189–278 in H. J. Brockmann, T. J. Roper, M. Naguib, K. E. Wynne‐Edwards, C. Barnard, and J. Mitani, eds. Advances in the study of behavior. Vol. 37. Academic Press, New York.']
  • ['Kilham, L. 1984. Intra‐ and extrapair copulatory behavior in American crows. Wilson Bulletin 96:716–717.']
  • ['Kokko, H., and I. Ots. 2006. When not to avoid inbreeding. Evolution 60:467–475.']
  • ['Konovalov, D. A., C. Manning, and M. T. Henshaw. 2004. KINGROUP: a program for pedigree relationship reconstruction and kin group assignments using genetic markers. Molecular Ecology Notes 4:779–782.']
  • ['Li, S. H., and J. L. Brown. 2002. Reduction of maternal care: a new benefit of multiple mating? Behavioral Ecology 13:87–93.']
  • ['Mays, H. L., T. Albrecht, M. Liu, and G. E. Hill. 2008. Female choice for genetic complementarity in birds: a review. Genetica 134:147–158.']
  • ['McGowan, K. J. 2001. Demographic and behavioral comparisons of suburban and rural American crows. Pages 365–381 in J. M. Marzluff, R. Bowman, and D. Donelly, eds. Avian ecology and conservation in an urbanizing world. Kluwer Academic, Norwell, MA.']
  • ['Rubenstein, D. R. 2007. Female extrapair mate choice in a cooperative breeder: trading sex for help and increasing offspring heterozygosity. Proceedings of the Royal Society B: Biological Sciences 274:1895–1903.']
  • ['Shields, W. M. 1982, Philopatry, inbreeding, and the evolution of sex. State University of New York Press, Albany.']
  • ['Townsend, A. K. 2009. Extrapair copulations predict extrapair fertilizations in the American crow. Condor 111:387–392.']
  • ['Townsend, A. K., A. B. Clark, K. J. McGowan, E. L. Buckles, A. D. Miller, and I. J. Lovette. 2009a. Disease‐mediated inbreeding depression in a large, open population of cooperative crows. Proceedings of the Royal Society B: Biological Sciences 276:2057–2064.']
  • ['Townsend, A. K., A. B. Clark, K. J. McGowan, and I. J. Lovette. 2009b. Reproductive partitioning and the assumptions of reproductive skew models in the cooperatively breeding American crows. Animal Behaviour 77:503–512.']
  • ['Tregenza, T., and N. Wedell. 2000. Genetic compatibility, mate choice and patterns of parentage: an invited review. Molecular Ecology 9:1013–1027.']
  • ['Trivers, R. 1972. Parental investment and sexual selection. Pages 136–179 in B. Campbell, ed. Sexual selection and the descent of man. Heinemann, London.']
  • ['Westneat, D. F., and I. R. K. Stewart. 2003. Extra‐pair paternity in birds: causes, correlates, and conflict. Annual Review of Ecology, Evolution, and Systematics 34:365–396.']
  • ['Westneat, D. F., A. B. Clark, and K. C. Rambo. 1995. Within brood patterns of paternity and paternal behavior in red‐winged blackbirds. Behavioral Ecology and Sociobiology 37:349–356.']
  • ['Williams, D. A., and A. M. Hale. 2008. Investment in nesting activities and patterns of extra‐ and within‐group genetic paternity in a cooperatively breeding bird. Condor 110:13–23.']
  • ['Wilson, T. M. 2008. Patterns of sentinel behavior at the nest in the cooperatively breeding American crow (Corvus brachyrhynchos). Binghamton University, Binghamton, NY.']