Some Measurements of Swallow Breeding Biology in Lowland Scotland

This Scottish study offers comparisons with a previous national Nest Record Card analysis based on mainly English data. In the north, clutches average larger and are laid later, and larger clutches are more successful. Within a clutch hatching appears not to be synchronised; and nestling growth rates are not correlated with brood size. The overall breeding success found in Lowland Scotland was 76.3%.