Research By training I am a behavioral ecologist, but in recent years I’ve become increasingly interested in behavioral physiology, as well as in the effects of environmental contaminants on behavior. Most of my research focuses on the evolutionary forces that shape animal social interactions, particularly reproductive, parental and aggressive behavior. I’m also interested in the evolution of life histories. I work with birds and fish in both laboratory and field settings. Continue reading to learn more about some of the projects I’m currently working on, as well as to download my curriculum vitae or PDF files of some of my papers. Lab Current members of my research group include Maureen Manning (technician) and Caleb Murphy (senior thesis student). Projects Behavioral endocrinology of dark-eyed juncos. Manipulations of plasma testosterone (T) levels in male dark-eyed juncos (a socially monogamous, ground-nesting songbird) have revealed myriad phenotypic effects (reviewed in Ketterson et al. 2001). With my colleagues, Ellen Ketterson and Val Nolan at the Center for the Integrative Study of Animal Behavior and the Department of Biology at Indiana University, I am currently investigating the role of T in mediating female behavior and the potential for intersexual conflict over optimal T-level expression. Field work for this project is conducted at the University of Virginia’s Mountain Lake Biological Station, where I am also collaborating with Amy Pedersen (Department of Biology, University of Virginia) and others on a long-term study of rodent-junco population dynamics. Phytoestrogen exposure in aquatic vertebrates. Phytoestrogens are a class of naturallyoccurring estrogenic compounds found in many plants, particularly soybeans and some tree species. Significant phytoestrogen levels have been reported downstream from some pulp and paper mills, but little is known about their effect on fish populations. I am in the beginning stages of research on the behavioral consequences of phytoestrogen exposure in fishes such as the fathead minnow (Pimephales promelas) and the fighting fish (Betta splendens). Aggressive behavior in male and female fighting fish. Male Betta splendens are widely known for their stereotyped agonistic displays and often-fatal displays of aggression. Females are also aggressive in a variety of inter- and intrasexual contexts. I am currently investigating the effects that intensive natural and artificial selection on male behavior have on female behavior, and ultimately, female fitness. This work will utilize a combination of behavioral, physiological and classical genetics approaches with both laboratory and field components. Visit the International Betta Congress to learn more about these fish. Incubation costs and life history tradeoffs in cavity-nesting birds. Most of what we know about avian incubation behavior comes from correlative studies, rather than direct manipulations of incubation conditions. Beginning in the fall of 2004, Dan Ardia (a Darwin Fellow in the University of Massachusett’s Organismic and Evolutionary Biology program) and I will begin a two-year project in which we will examine the costs and consequences of incubation behavior in house wrens (Troglodytes aedon) through experimental manipulations of the thermal environment, female condition, and maternal effects. This field work will be conducted in and around Amherst, Massachusetts. Peer-reviewed publications (as of 3/1/04) *indicates undergraduate co-author Clotfelter, E.D., O’Neal*, D.M., Gaudioso*, J.M, Casto, J.M., Parker-Renga, I.M., Snajdr, E.A., Duffy, D.L., Nolan, V. Jr. and Ketterson, E.D. In press. Consequences of elevating plasma testosterone in females of a socially monogamous songbird: evidence of constraint on male evolution? Hormones and Behavior. Ingham*, R.R., Gesualdi*, D.A., Toth, C.R. and Clotfelter, E.D. In press. Effects of genistein on growth and development of aquatic vertebrates. Bulletin of Environmental Contamination and Toxicology. Clotfelter, E.D. and Paolino*, A.D. 2003. Bystanders to contests between conspecifics are primed for increased aggression in male fighting fish. Animal Behaviour 66: 343-347. Whittingham, L.A., Dunn, P.O. and Clotfelter, E.D. 2003. Parental allocation of food to nestling tree swallows: the influence of nestling behaviour, sex and paternity. Animal Behaviour 65: 1203-1210. Clotfelter, E.D., Schubert*, K.A., Nolan, V., Jr. and Ketterson, E.D. 2003. Mouth color signals thermal state in nestling dark-eyed juncos. Ethology 109: 171-182. Nolan, V., Jr., Ketterson, E.D., Cristol, D.A., Rogers, C.M., Clotfelter, E.D., Titus, R.C., Schoech, S.J. and Snajdr, E.A. 2002. Dark-eyed junco (Junco hyemalis). In The Birds of North America, No. 716 (Poole, A. and Gill, F., Eds.). The Birds of North America, Inc., Philadelphia, PA. Clotfelter, E.D., Nolan, V., Jr. and Ketterson, E.D. 2001. The effects of experimentally elevated testosterone and food deprivation on food consumption and prey size preferences in male dark-eyed juncos (Junco hyemalis). Ethology 107: 439-449. Ketterson, E.D., Nolan, V. Jr., Casto, J.M., Buerkle, C.A., Clotfelter, E.D., Grindstaff, J.A., Jones, K.J., Lipar, J.L., McNabb, F.M., Neudorf , D.L., Parker-Renga, I., Schoech, S.J. and Snajdr, E. 2001. Testosterone, phenotype, and fitness: a research program in evolutionary behavioral endocrinology. In Avian Endocrinology (Dawson, A. and Chaturvedi, C.M., Eds.), pp. 19-40. Narosa: New Dehli. Clotfelter, E.D., Whittingham, L.A. and Dunn, P.O. 2000. Laying order, hatching asynchrony and nestling body mass in tree swallows (Tachycineta bicolor). Journal of Avian Biology 31: 329-334. Clotfelter, E.D. and Yasukawa, K. 1999a. The effect of aggregated nesting on red-winged blackbird nest success and brood parasitism by brown-headed cowbirds. Condor 101: 729-736. Clotfelter, E.D. and Yasukawa, K. 1999b. Impact of brood parasitism by brown-headed cowbirds on the reproductive success of red-winged blackbirds. Condor 101: 105-114. Clotfelter, E.D. and Yasukawa, K. 1999c. The function of early onset of nocturnal incubation in the red-winged blackbird. Auk 116: 417-426. Clotfelter, E.D., Yasukawa, K., and Newsome, R.D. 1999. The effects of prescribed burning and habitat edges on brown-headed cowbird parasitism of red-winged blackbirds in southern Wisconsin. Studies in Avian Biology 18: 275-281. Clotfelter, E.D. 1998. What cues do brown-headed cowbirds use to locate red-winged blackbird host nests? Animal Behaviour 55: 1181-1189. Clotfelter, E.D. 1997. Red-winged blackbird parental investment following brood parasitism by brown-headed cowbirds: is parentage important? Behavioral Ecology and Sociobiology 41: 193-201. Clotfelter, E.D. 1996. Mechanisms of facultative sex ratio variation in zebra finches (Taeniopygia guttata). Auk 113: 441-449. Clotfelter, E.D. 1995. Courtship displays and intrasexual competition in the bronzed cowbird. Condor 97: 816-818. Clotfelter, E.D. and Brush, T. 1995. Unusual parasitism by the bronzed cowbird. Condor 97: 814-815.