Student Scholars Day

Parental Decisions and Paternity in the Yellow Warbler

Henry Hall Atrium 73

Yellow Warblers (Dendroica petechia) are socially monogamous within a breeding season, and both parents care for the young. However, both males and females participate in extra-pair copulations, which may result in mixed paternity broods containing offspring of the social father as well as extra-pair offspring from other males. Eggs are laid over a 5-6 day period and males preferentially feed larger young who hatch from earlier eggs. This may be an adaptation to bias investment toward their own offspring if larger chicks are more likely to be their genetic progeny. We will genotype 200 offspring and adult males at 8 microsatellite loci using the polymerase chain reaction. Based on the genotypes of the males and offspring, we will determine which offspring resulted from extra-pair fertilizations, whether extra-pair offspring are more likely to be large or small, and whether males can use offspring size as a cue to successfully bias their investments toward their own offspring.