Joseph Haydock

Associate Professor of Biology

I am interested in avian social behavior and I ask questions from an evolutionary perspective. I use a combination of field observations, experiments in natural populations and molecular genetic techniques in the laboratory. In the past 10 years I have...

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I am interested in avian social behavior and I ask questions from an evolutionary perspective.  I use a combination of field observations, experiments in natural populations and molecular genetic techniques in the laboratory. In the past 10 years I have had over 30 students participate in research my lab. These students have had the opportunity to study the evolution of social behavior and learn the molecular genetic techniques I use in my lab.
Koenig, W.D. E.L. Walters and J. Haydock. 2011. Fitness consequences of within-brood dominance in the cooperatively breeding acorn woodpecker. Behavioral Ecology and Sociobiology.  65:2229-2238.

Koenig, W.D. E.L. Walters and J. Haydock. 2011. Variable helper effects, ecological conditions, and the Evolution of Cooperative Breeding in the Acorn Woodpecker. American Naturalist: 178:145-158.

Koenig, W.D., A.H. W.B. Monahan, J. Haydock, J.M.H Knops, W.J. Carmen. 2009 Mast-producing trees and the geographical ecology of western scrub-jays. Ecography 32: 561-570.

Koenig, W.D., E.L. Walters, J. Haydock. 2009 Helpers and egg investment in the cooperatively breeding acorn woodpecker: testing the concealed helper effects hypothesis. Behavioral Ecology and Sociobiology 63: 1659-1665.

Koenig, W.D. and J. Haydock. Reproductive skew in acorn woodpeckers. 2009 In Jones, C.B. and R. Hager eds. Reproductive Skew in Vertebrates: Behavioral, Ecological, and Genetic Factors.

Koenig, W. D., A. H. Krakauer, W. B. Monahan, J. Haydock, J. M. H. Knops, and W. J. In Press Carmen. In press. Mast-producing trees and the geographical ecology of western scrub-jays. Ecography

Ferree, E. D., J. L. Dickinson, D. Kleiber, C. A. Stern, J. Haydock, M.T. Stanback, V. Schmidt, L. Eisinger, C. Stolzenburg. 2008. Development and cross-species testing of western bluebird (Sialia mexicana) microsatellite primers. Molecular Ecology Resources 8:1348–1350.

Koenig, W. D., M. T. Stanback, and J. Haydock. 2006. Abbreviated inner primaries: a sex-linked dimorphism in the Acorn Woodpecker. Journal of Field Ornithology 77:157-162.

Koenig, W. D., and J. Haydock. 2004. Incest and incest avoidance, Pages 142-156 in W. D. Koenig, and J. L. Dickinson, eds. Ecology and Evolution of Cooperative Breeding in Birds. Cambridge, Cambridge University Press.

Haydock, J., and W. D. Koenig. 2003. Patterns of reproductive skew in the polygynandrous acorn woodpecker. American Naturalist 162:277-289.

Haydock, J., and W. D. Koenig. 2002. Reproductive skew in the polygynandrous acorn woodpecker. Proceedings of the National Academy of Sciences, USA 99:7178-7183.

Marks, J. S., J. L. Dickinson, and J. Haydock. 2002. Serial polyandry and alloparenting in Long-eared Owls. Condor 104:202-204.

Koenig, W. D., and J. Haydock. 2002. Group sex in the acorn Woodpecker: who comes out on top and why? Biologist 49:150-154.

Koenig, W. D., and J. Haydock. 2001. Dividing up the kids. Science (Washington D C) 291:442-443.

Haydock, J., W. D. Koenig, and M. T. Stanback. 2001. Shared parentage and incest avoidance in the cooperatively breeding acorn woodpecker. Molecular Ecology, 10:1515-1525.

Koenig, W. D., M. T. Stanback, J. Haydock, and F. Kraaijeveld-Smit. 2001. Nestling sex ratio variation in the cooperatively breeding acorn woodpecker (Melanerpes formicivorus). Behavioral Ecology and Sociobiology 49:357-365.
The focus of my research is the acorn woodpecker (Melanerpes formicivorus), which has one of the most complex social systems among vertebrate societies. Social groups consist of up to 15 individuals, including up to seven cobreeding males and four joint-nesting females that compete for the opportunity to mate. Groups also contain non-breeding helpers from prior breeding attempts who delay dispersal. All group members defend engage in territorial defense, feeding of nestlings and collecting acorns that they store in granaries. I collaborate in my research with Walter Koenig at Cornell University and Eric Walters at Old Dominion University. Acorn woodpeckers have been under study at Hastings Natural History Reservation in central coastal California since 1971.