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Population Density, Circulating Testosterone And Dawn Chorus Behaviour In White-Throated Sparrows (Zonotrichia Albicollis), Simon Richard Hall

Theses and Dissertations (Comprehensive)

An integrative approach to biological research has facilitated the study not only of specific phenomena, but of the connections between these phenomena. A particularly striking example is that of the relationships between testosterone, social behavior, and social context. Increased levels of testosterone increase the frequency of aggressive behaviors and reduce the quality of parental care in many songbird species, and these changes in behavior can affect the surrounding social environment. Different social contexts, population density as a readily studied example, affect the cues that control the release of testosterone into the bloodstream. The distinct tan-stripe and white-stripe phenotypic morphs of …