PI: Michael S. Webster Co-PI: Hubert Schwabl and Jordan Karubian

One primary goal of evolutionary biology is to explain biological diversity, both within and among species. Many species show pronounced phenotypic variation in both behavior and morphology, with individuals of one phenotype looking and behaving very differently from individuals of another phenotype. For example, males of the Australian red-backed fairy-wren (Malurus melanocephalus) are of two different types: some males breed in bright plumage, provide relatively little parental care, and seek extrapair copulations, whereas other males are cryptically colored, provide much parental care, and do not appear to seek extrapair copulations. An understanding of this sort of phenotypic polymorphism requires an understanding of both the mechanisms that produce it and the evolutionary forces that create and maintain it. In this project, Webster et al. will examine the hormonal/physiological mechanisms and also the evolutionary forces responsible for polymorphism in the red-backed fairy-wren. Correlational analyses of changes in hormone levels will be combined with a hormone manipulation experiment to determine the mechanisms that cause a male to adopt one plumage type or the other. In addition, experiments with wild and captive birds will be used to thoroughly test whether males change plumage type in response to social cues. At a functional level, observations of wild birds, combined with field experiments and genetic analyses of parentage, will be used to determine the total reproductive success of males with different phenotypes. This project will be among the first to examine a complex intraspecific polymorphism in an endothermic vertebrate from both mechanistic and functional perspectives. As such, the study will serve as a model for understanding polymorphism in other endothermic organisms, and also as a model for a pluralistic approach to the study of natural phenomena. In doing so, this project will directly address several current controversies in behavioral and evolutionary biology. Specifically, this study will: (1) lead to a better understanding of the function of conspicuous and polymorphic traits; (2) help clarify the role of hormones in the development of plumage color; and (3) elucidate the mechanistic connections between social behavior and morphology.

Agency
National Science Foundation (NSF)
Institute
Division of Integrative Organismal Systems (IOS)
Application #
0213075
Program Officer
Daniel D. Wiegmann
Project Start
Project End
Budget Start
2002-09-15
Budget End
2009-08-31
Support Year
Fiscal Year
2002
Total Cost
$437,623
Indirect Cost
Name
Washington State University
Department
Type
DUNS #
City
Pullman
State
WA
Country
United States
Zip Code
99164