Ovary mass and stable hydrogen isotope data for resident and migratory female dark-eyed juncos

This dataset includes ovary mass and stable hydrogen isotope compositions of feathers and claws from resident and migratory female dark-eyed juncos (Junco hyemalis) collected during early spring at Mountain Lake Biological Station, Pembroke, Virginia. A total of 18 migrant and 15 resident female dark-eyed juncos, a songbird that exhibits seasonal sympatry, were caught during March-April. Stable hydrogen isotopes were used to infer relative breeding and wintering latitude of migrants. Ovary mass served as a proxy for reproductive development. These data were used to explore whether seasonal sympatry fosters or inhibits genetic divergence between migrants and residents and to the extent that this depends on their respective timing of reproduction. There are two files in this dataset: 1) a comma delimited machine-readable file (*.csv) that represents the data dictionary, and 2) a comma delimited machine-readable file (*.csv) containing the data.