Breeding biology and ecology of Great Tinamous: Female joint-nesting, extra-pair paternity and natural history

I conducted the first long-term study of the breeding biology and ecology of Great Tinamous (Tinamus major). Tinamous have uniparental male care, which makes this group a good model to test sexual selection theories and study the evolution of multiple mating and male care.; I developed field techniques to catch birds and to collect DNA samples from chicks and incubating males. I also developed the first tinamou microsatellite library to conduct parentage analysis of clutches.; I found that female joint-nesting is common and 65% of nests have more than 3 eggs. Individual females lay up to 3 eggs in the male's nest, and males incubate as many as 8 eggs. Joint-nesting is beneficial because larger clutches do better than smaller clutches due to the "dilution effect": when snakes prey upon large clutches, some eggs survive, while eggs in 3 egg clutches are always completely consumed. As a result eggs in larger clutches (>3 eggs) have significantly higher individual survival probability than eggs in smaller clutches (3 eggs). These results offer the first empirical evidence for "dilution effect" in avian nests.; Male investment in care is high: incubation lasts 17 days and nest attentiveness is >98%. Contrary to predictions of current theory on extra-pair paternity (EPP), Great Tinamous have the highest reported EPP levels of any species with uniparental male care (35%). Males who incubated larger clutches sired more offspring even though they also had more EPP in their nests, and this benefit likely accounts for the male's acceptance of EPP.; Great Tinamous lay conspicuous turquoise eggs, which I propose have evolved as a female signal to indicate nest location to other females, since joint-nesting is beneficial. Although more than 80% of nests are preyed upon, most predators use cues from the incubating male and not vision to find the eggs.; Females have larger home ranges than males, but neither sex is territorial and both sexes use the same call, suggesting that sexual selection is not stronger in either sex, or that natural selection acts against the development of secondary sexual characters.