The number of butterfly species in woodlands.

The number of butterfly species present in 22 woods in eastern England was recorded during fortnightly visits between May to October 1978. A total of 26 species was observed. The number of species present was significantly correlated with the area of woodland but not with the area of glades and rides, which provided both larval food plants and adult foraging sites. The number of vagile species, but not the number of poorly vagile species, present was correlated with the area of woodland within 1 km of the study wood, this being a measure of the sources of potential colonizers. It was predicted that a woodland area of about 460 ha would be required to support all the species recorded in the study.