This award continues a 30-year study of social behavior of colonially nesting cliff swallows in southwestern Nebraska. Annual survival and colony choice will be studied for a sample of over 200,000 individually marked birds by re-catching birds at different nesting colonies. The data gathered will examine how size of a nesting colony affects annual survival of cliff swallows and whether individuals use the same size colony each year. The research will also determine why nesting success in most seasonally breeding birds declines with time during the summer. Experimental treatment of cliff swallow colonies with insecticide creates conditions that stimulate some birds to nest much later in the summer than typically seen and will provide the opportunity to compare first-year survival of birds raised both early and late in the season.
Many kinds of animals live in groups of different sizes, including humans, and this research addresses fundamental questions about what factors create and maintain diversity in group sizes; what is discovered for swallows may apply to other species that live in social groups. Undergraduate students will be heavily involved, many of whom are women, minorities, and other underrepresented groups in research. This work will be relevant for conservation, because understanding colony choice and annual variation in survival probabilities of species such as cliff swallows could help in establishing management guidelines for similar migratory species that are declining.
