Faculty & Research
- Contact Information
- Contact Ellen Ketterson by ketterso [at] indiana [dot] edu
- By telephone: 812-855-6837/5-1096(lab)
- By fax: 812-855-6705
- JH 033
- Evolution, Ecology & Behavior
- Research Areas
Ph.D., Indiana University, 1974
Postdoctoral Fellow, Washington State University, 1974-75
We take an experimental approach to life-history evolution that we call ’phenotypic engineering’. By treating birds with hormones, documenting the phenotypic consequences of hormonal treatment, and relating these consequences to fitness, we hope to understand how natural selection shapes organisms as integrated units. Our study animal is the dark-eyed junco, and we have found that testosterone affects numerous aspects of the male phenotype in free-living juncos, including song, parental behavior, home range size, attractiveness to females, immune capacity, corticosteroid responses to stress, regulation of body mass, and timing of molt, to name a few. With respect to fitness, males treated with testosterone are less successful at rearing offspring with their social mates but more successful at siring offspring by means of extra-pair fertilizations. Our current goals include investigation of the extended phenotypic effects of testosterone on a male’s associates, including his mate and offspring. We are also investigating constraints on testosterone, including correlated responses in females and effects of testosterone on males during the non-breeding season.
Our studies of migration have focused on factors that promote site fidelity, the role of experience in regulating onset and termination of migration, and the relative importance of a series of selective factors in shaping the distance an individual migrates. These factors include dominance status in winter, arrival time at breeding areas in spring, risk of mortality during migration, and physiological adaptations (such as fattening) for coping with unpredictable environments.
Current and recent graduate students have studied the role of maternal steroids in early development in red-winged blackbirds, European starlings, and dark-eyed juncos; seasonal profiles of testosterone and prolactin in red-eyed vireos and solitary vireos; the influence of testosterone on the pre-basic molt in dark-eyed juncos, mate choice across subspecific boundaries in dark-eyed juncos; genetics of variation in sexually selected traits in orioles; transmission of passive immunity in Japanese quail and pied flycatchers, ageing and the stress response in common terns, correlational selection on body size and an attractive plumage trait in dark-eyed juncos, testosterone, aggression, nest defence, and immune function in female dark-eyed juncos, hormonal correlates of dominance in female dark-eyed juncos, variation among female dark-eyed juncos in extra-pair fertilizations, hormones and social behavior in the phainopepla, regulation of seasonal reproduction by novel peptides in dark-eyed juncos.
- McGlothlin, J. W. and E. D. Ketterson. 2008. Hormones and the continuum between adaptation and constraint. Philosophical Transactions of the Royal Society of London B, published on line. doi:10.1098/rstb.2007.0002
- McGlothlin, J.W., Jawor, J.M., Greives, T.J., Casto, J.M., Phillips, J.L. and E. D. Ketterson. 2008 Hormones and honest signals: males with largest ornaments elevate testosterone more when challenged. Journal of Evolutionary Biology, published on linedoi:10.1111/j.1420-9101.2007.01471.x
- Jawor, J.M., McGlothlin, J.W., Casto, J.M., Greives, T. J., Snajdr, E., Bentley, G. E., and E. D. Ketterson. 2007. Testosterone response to GnRH in a female songbird varies with stage of reproduction: implications for adult behaviour and maternal effects. Functional Ecology 21:767-775.
- McGlothlin, J. W., Jawor, J.M., and E. D. Ketterson. 2007. Natural variation in a testosterone-mediated trade-off between mating effort and parental effort. American Naturalist, 170, published on line, DOI: 10.1086/522838
- Clotfelter, E.D., Pedersen, A.B., Cranford, J.A., Ram, N., Snajdr, E.A., Nolan Jr., V. and E.D. Ketterson. 2007. Acorn mast drives long-term dynamics of rodent and songbird populations. Oecologia 154:493-503. DOI 10.1007/s00442-007-0859-z
- Soini, H. A., Schrock, S.E., Bruce, K.E., Wiesler, D., Ketterson, E.D., and M.V. Novotny. 2007. Seasonal variation in volatile compound profiles of preen gland secretions of the dark-eyed juncos (Junco hyemalis). J. Chemical. Ecology, 33:183-198. DOI 10.1007/s10886-006-9210-0
- Heidinger, B. J., Nisbet, I.C.T., Lepire*, J.A., and E.D. Ketterson. 2006. Attenuation of the stress response facilitates increased reproductive investment with age, Proceedings Royal Society, Series B 273 (1598): 2227-2231. doi: 10.1098/rspb.2006.3557
- Reed, W.L, Clark, M.E., Parker, P.G., Raouf, S.A., Arguedas, N., Monk, D.S, Snajdr, E., Nolan, V. Jr., and E.D. Ketterson. 2006. Physiological effects on demography: A long-term experimental study of testosterone's effects on fitness. American Naturalist, 167: 667-683.
- Zysling, D.A., Greives*, T.J., Breuner, C., Casto, J.M., Demas, G.E., and E. D. Ketterson. 2006. Behavioral and physiological responses to experimentally elevated testosterone in female dark-eyed juncos (Junco hyemalis carolinensis). Hormones and Behavior 50(2): 200-207.
- Ketterson, E.D., V. Nolan Jr., and M. Sandell. 2005. Testosterone in females: mediator of adaptive traits, constraint on the evolution of sexual dimorphism, or both? American Naturalist 166: S85-S98.