Most of my research has focused on sexual selection, mating systems, or parental care. I have been especially interested in how the spatial and temporal availability of potential mates affects evolution of various male traits. For example, female 13-lined ground squirrels breed fairly synchronously, yet the home ranges of any two females that are in estrus simultaneously may be several hundred meters apart. Moreover, female 13-lined ground squirrels tend to mate with more than one male, and the resulting sperm competition features a first-male advantage. This combination of female spatial dispersion, female breeding synchrony, and paternity skewed toward the first mate of females appears to have favored male mobility, spatial memory, the ability of males to distinguish how soon certain females will become sexually receptive, plus an element of male "choosiness" based on the mating history of a prospective mate.

Some of the collaborative work I've done on house sparrows also has examined how the characteristics of one sex shape the behavior of the opposite sex. Male house sparrows vary widely in the amount of parental care they provide, and we used experimental approaches to determine the sensitivity of female parents to alterations in their mates’ contributions, as well as the impact of reduced male parental care on offspring welfare and male reproductive success. Our most recent project on house sparrows assessed whether males display any sensitivity to increases or reductions in the time females spend incubating; we also investigated sex differences in parental effectiveness at incubation as one potential explanation for why female sparrows contribute so much more than males to this form of parental care.

Biparental care is a relatively simple system in which to study cooperative behavior among unrelated individuals.  Since retiring from OU in 2013, I have used one of our long-term datasets to examine other options available to a house sparrow parent that is paired to an individual that furnishes inadequate levels of care (i.e., is uncooperative). Retirement has also provided an opportunity to explore other contexts in which individuals gain direct fitness benefits by contributing to a common good.      

• Schwagmeyer, P. L. 2014.   Partner switching can favour cooperation in a biological market. Journal of Evolutionary Biology 27:1765-1774.


• Parker, G.A., Schwagmeyer, P.L., Mock, D.W.  2014.  The asymmetric incubation game: a prospective model and a house sparrow investigation. Animal Behaviour 93:37-47.


• Schwagmeyer, P. L., Parker, P.G, Mock, D. W. and Schwabl, H. 2012.  Alternative matings and the opportunity costs of paternal care in house sparrows. Behavioral Ecology 23:1108-1114.


• Mock, D.W., Schwagmeyer, P. L., and Dugas, M. 2009. Parental provisioning and nestling mortality in house sparrows. Animal Behaviour 78:677-684.


• Schwagmeyer, P.L. and D.W. Mock.  2008.  Parental provisioning and offspring fitness: size matters.  Animal Behaviour 75:291-298.


• Schwagmeyer, P. L., Bartlett, T. L. and Schwabl, H.G. 2008.  Dynamics of house sparrow biparental care:  What contexts trigger partial compensation? Ethology 114:459-468.


• Edly-Wright, C., P.L. Schwagmeyer, P.G. Parker, and D.W. Mock. 2007.  Genetic similarity of mates, offspring health and extrapair fertilization in house sparrows.  Animal Behaviour 73:367-378.


• Kopisch, A., P.L. Schwagmeyer, and D.W. Mock.  2005.  Individual consistency in parental effort across multiple stages of care in the house sparrow, Passer domesticus.  Ethology 111:1062-1070.


• Bartlett, T.L., D.W. Mock, and P.L. Schwagmeyer.  2005.   Division of labor: Incubation and biparental care in the house sparrow, Passer domesticus.  Auk 122:835-842.


• Schwagmeyer, P.L., H.G. Schwabl, and D.W. Mock.  2005.  Dynamics of biparental care in house sparrows: hormonal manipulations of paternal contributions.  Animal Behaviour 69:481-488.