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http://etd.fcla.edu/UF/UFE0001063/quader_s.pdf

The evolution and persistence of elaborate traits can often be explained by sexual selection, the evolutionary process associated with acquiring mates. When these traits are complex behavioral patterns, changes in neural structure and learning ability may be involved. One such behavior is nest building, which is done with particularly impressive skill by male weaverbirds. In most weaverbirds, males build nests without any female assistance, and females are thought to choose mates by evaluating their nests. Although there are some data on mate choice in weaverbirds from aviaries, information on nesting and mating patterns and their consequences is lacking from the wild. Here, I describe results from a field study of baya weaverbirds, Ploceus philippinus, in India. I examine male and female nesting decisions in relation to an important abiotic factor, wind. I also ask whether nest structure is an important cue to females while choosing mates, and evaluate the possibility that females use male phenotype and nest location instead. To understand why females pay attention to particular characters, I investigate the benefits of female choice by examining which factors best explain variation in nesting success. I also use microsatellite DNA tools to test the assumption that outward patterns of pairing and egg laying reflect actual mating and nesting decisions. I find little evidence linking female choice to nest structure. Instead, nest location seems to play a larger role. Appropriate nest location is also important in male settlement, and males cluster their nests in leeward locations, where nests are protected from strong winds. Also, nests placed high above ground are both preferred by females and safer from predators than are lower nests. Thus, nest location is a particularly good predictor of nesting success, which may explain why females pay little attention to nest structure. Molecular analyses indicate that most clutches are fertilized by the builder of the nest in which they are laid, and show that the level of intraspecific brood parasitism is low. Although I found little evidence of female choice for nest structure in the baya weaverbird, past choice may have led to the current distribution of trait values.