Why do both female and male motmots have such extraordinary tails, and why do they wag their tails back-and-forth? I investigated the adaptive significance of the elaborate monomorphic tail plumage in the Turquoise-browed Motmot (Eumomota superciliosa) for my Ph.D. at Cornell University, under the direction of Stephen Emlen and Paul Sherman.

My research demonstrated that the selection operates on the elaborate tail of the male and female motmots in different ways: the tail functions as a sexually selected signal in males, whereas natural selection maintains both the male and female tail for pursuit-deterrent signaling. My research also provided insight into rare dishonest signaling, and shows how preemptive pursuit-deterrent signal can be favored. click to read more about my research on motmots


I am investigating the role of female coloration in signaling status both within and between the sexes in Streak-backed Orioles (Icterus pustulatus). This research is part of an NSF postdoctoral project in collaboration with Robert Montgomerie at Queen's University. We are testing the adaptive significance of female color in the field in Mexico, and we are using the comparative method to assess whether the evolutionary loss of elaborate female character states, and the subsequent evolution of sexual dichromatism, has occurred in migratory species as a result of the reduction of adaptive benefits associated with elaborate female characters. We are also investigating adaptive explanations for why females sing five-times more often than males in the Streak-backed Oriole. click to read more about my research on orioles


In collaboration with Keith Tarvin at Oberlin College, I am testing whether females signal status with bill coloration in the American Goldfinch (Carduelis tristis). Although goldfinches are sexually dichromatic, and female plumage is rather drab, female bill color changes from grey-brown to bright orange during the breeding season. We are investigating whether the orange female bill functions as a sexual/social signal of fighting ability using aviary-based dominance experiments. In addition, we are testing for male mate choice in aviary experiments, and in the field, we are testing whether males invest more into broods produced by females with color-augmented bills. click to read more about my research on goldfinches

© 2006 Troy Murphy