Most of the research of my students and I seeks to understand the evolution of diversity in the sexual behavior of animals. This is addressed at three levels: (1) among individuals in populations, (2) among populations in species and (3) among related species in genera. Most subjects currently under study are amphibians, mainly salamanders but also some frogs. Work at Level 1 seeks to understand variation in individual behavior within the framework of sexual selection, and relies on the integration of behavioral, ecological and physiological data from both lab and field. Work at Level 2 addresses the extent to which population divergence in behavior promotes sexual incompatibility among populations. Such divergence can result in a decrease in gene flow (measured using molecular markers) and may facilitate full speciation. The aim of studies at Level 3 is to understand broad patterns of behavioral evolution by superimposing ethograms of courtship onto independent phylogenies for clades of closely related taxa. Other research interests include studies of stress in captive wolves, effects of pesticides on the behavior of exposed animals (mainly amphibian larvae and earthworms), and the impact of non-native aquatic plants on the survival and development of larval amphibians.
Verrell, P.A. 2006. The female reproductive cycle of the North American salamander Ambystoma macrodactylym columbianum. Amphibia-Reptilia 27: 274-277.
Davis, A. B. & P. A. Verrell. 2005. Demography and reproductive ecology of the Columbia spotted frog (Rana luteiventris) across the Palouse. Canadian Journal of Zoology 83: 702-711.
Mabry, M. & P. Verrell, P. 2004. Stifled sex in sympatry: patterns of sexual incompatibility among desmognathine salamanders. Biological Journal of the Linnean Society 82: 367-375.
Verrell, P. & E. Van Buskirk, E. 2004. As the worm turns: Eisenia fetida avoids soil contaminated by a glyphosate-based herbicide. Bulletin of Environmental Contamination and Toxicology 72: 219-224.
Cipponeri, T. & P. Verrell. 2003. An uneasy alliance: unequal distribution of affiliative interactions among members of a captive wolf pack. Canadian Journal of Zoology 81: 1763-1766.
Mabry, M. & P. Verrell. 2003. All are one and one is all: sexual uniformity among widely separated populations of the North American seal salamander, Desmognathus monticola. Biological Journal of the Linnean Society 78: 1-10.
Stephenson, B. & P. Verrell. 2003. Courtship and mating of the tailed frog (Ascaphus truei). Journal of Zoology, London 259: 15-22.
Verrell, P. 2003. Population and species divergence of chemical cues that influence male recognition of females in desmognathine salamanders. Ethology 109: 577-586.