Commonness and rarity in British butterflies.
Commonness and rarity among British butterflies were examined by relating features of biology and ecology to geographical distribution. No single attribute totally differentiated between common and rare species. Several characteristics which are correlated with abundance appeared likely to influence the capacity of species to exploit the artificial disturbed and productive habitats creased by modern land use. Common species were relatively large, formed 'open' or migratory populations, exploited larval food plants in productive habitats, had rapidly maturing larvae, hibernated as pupae or imagos and extended into parts of northwest Europe with relatively low summer temperatures. Common butterflies are divided into those which produce several broods per year, are polyphagous, utilize larval food plants of disturbed habitats and have a short-lived imago, and those which are single-brooded, monophagous with a long-lived imago. Rare species were variously large or small, tended to occur in 'closed' populations, produced a single brood per year, exploited larval food plants in unproductive habitats and produced long-lived larvae.