Habitat Selection in Birds

THE afforestation of the Breckland heath with young pines provided David Lack (J. Animal Ecol., Nov. 1933) with the opportunity of studying the changes in avifauna. Until the trees are some four years old, only the heathland birds occur, but within the next five years these disappear and are replaced by a new avifauna. The most marked features are the steady decrease of the skylark and the meadow pipit, and the appearance and rapid increase of the willow warbler.