Journal of Ethology

, Volume 26, Issue 1, pp 137–144 | Cite as

Female–female competition or male mate choice? Patterns of courtship and breeding behavior among feral horses (Equus caballus) on Assateague Island

  • David M. PowellEmail author


Previous research on the Assateague horses found that high-ranking females had more surviving offspring than low-ranking females. Variance in reproductive success may be the result of a variety of proximate processes that affect sexual behavior such as mate choice and mate competition. A study was done to determine whether patterns of courtship, social, and sexual behavior could be identified that would suggest mate choice and/or mate competition. Behavioral data were collected from approximately 40 sexually mature mares living in harem bands. Stallions showed more interest in the eliminations of dominant mares than subordinate mares. Males also engaged in significantly more high-intensity (e.g., mounts and copulations) sexual behavior with dominant mares than subordinate mares, and there was a trend for males to engage in more low-intensity (e.g., flehmen and ano-genital sniffing) sexual behavior with dominant mares than subordinate mares. There was no effect of mare rank on spatial relationships with the stallion; however, dominant mares did attempt to restrict reproductive access to the stallion by harassing and disrupting copulations. Higher foaling rates among dominant mares on Assateague Island could therefore be the result of rank-related mate choice by stallions and direct female competition for mating opportunities.


Mate choice Female competition Dominance Horses Copulation harassment 



I must thank my field staff: Paul Varga, Tim Hadlock, and 63 Earthwatch volunteers for their assistance with this research. I also thank Allison Turner, Jack Kumer, and Carl Zimmerman at the Assateague Island National Seashore for permission to work at the site and for access to records on the horses. This work was supported by a Pre-doctoral Fellowship from the Smithsonian Institution, the Department of Zoological Research of the National Zoological Park, the Biology of Small Populations NSF training grant at the University of Maryland (Grant #BIR 9602266), Earthwatch, Sigma Xi, and the Abbott and Nelson Funds of the Smithsonian Institution. I would like to thank Devra Kleiman, James Dietz, Gerald Wilkinson, Sue Carter-Porges, Estelle Russek-Cohen and two anonymous reviewers for their comments on this research.


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Copyright information

© Japan Ethological Society and Springer 2007

Authors and Affiliations

  1. 1.Department of MammalogyWildlife Conservation Society/Bronx ZooBronxUSA

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