9700811 Webster One of the goals of parental investment theory is to explain parental decisions based upon costs and benefits of the behavior. Recent use of molecular techniques has reveal that, in many systems, offspring are not necessarily sired by their social fathers Several studies have considered whether this reduction in paternity affects male parental care, and mixed findings have resulted. Few, however, have gone further to examine the mechanisms behind the observed male behavior. This two-year project will examine factors influencing male responses to reduced paternity in a North American passerine, the Black-throated Blue Warbler. Variation in parentage within broods has been detected in previous seasons; a combination of multilocus DNA fingerprinting and PCR-amplified microsatellites will be used to identify genetic fathers of all offspring in upcoming years. Focal observations and experimental manipulations will both be used to distinguish between a set of alternative hypotheses set forth to explain male parental care patterns in response to reductions in paternity. This study will help explain the currently poorly understood patterns of within- and between- species variation in parental care provide information about factors influencing male adaptive responses, and add to knowledge of the breeding ecology of this species.
