Dataset used to investigate the geographic variation in clutch size of the Varied Tit in East Asia

This dataset was created to analyze the geographic variation in clutch size of the Varied Tit <i>Sittiparus</i><i> </i><i>varius</i>. Clutch size data were collected across an extensive range in East Asia by reviewing the literature and adding our original records. The geographic coordinates, subspecies, habitat size, elevation, and forest vegetation type were identified for each study site from literature and several other web sources. Data preparation details and references are presented in the separate sheets.