Selective factors, evolution of breeding strategies and conservation biology of birds

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My research identifies and explains adaptations for breeding in birds, and develops approaches for conservation of birds. I use an experimental, hypothesis testing approach in field studies often coupled with laboratory work with either molecular genetics and/or stable isotope techniques      We use Tree Swallows and Barn Swallows, both with breeding systems that are amenable to experimentation, to study breeding adaptations. Tree Swallows show high rates of extra-pair paternity (EPP) (up to 80% of nests), yet the adaptive basis for high rates of EPP remains elusive. I seek to determine why some females engage in epc's and others do not. We will use Tree Swallows to examine proximate mechanisms of mate choice, especially mate choice copying, to develop insights into the high variability in rates of extra-pair paternity.   We will use Barn Swallows to examine the role of plumage and morphometry in driving mate choice decisions and to test hypotheses regarding optimum levels of inbreeding (and hence levels of heterozygosity).  I also propose establishing groundwork for comparative studies in Mexico, in conjunction with the Swallows of the Americas project.      Golden-winged Warblers face potential extinction due to hybridization with congeneric Blue-winged Warblers. We use genetic analysis (AFLPs) to determine levels of introgression and determine rates of EPP to establish its role in hybridization.  We also examine habitat use patterns and aspects of nest success in relation to hybrid status to determine the role of hybridization in population declines.     Cerulean Warbler populations have declined dramatically, yet in the northern parts of the range fairly dense populations enjoy high nesting success. Our molecular genetics and stable isotope work testing  source-sink hypotheses shows some evidence of directional gene flow. Further work will focus on dispersion of breeding populations in relation to habitat to determine the role of social interactions and loose 'coloniality' in driving habitat use decisions.