The previous volume of this atlas was the result of the first national survey of breeding birds in Britain and Ireland and its maps presented data only in the confirmed or probable breeding of each species in each grid square. In this more detailed volume, each species account includes three maps, one showing breeding distribution as before, one in full colour showing relative abundance of the species throughout its range, and one highlighting changes in distribution between the current and original surveys. A text, tables and vignette complete each double-page spread. A detailed introduction outlines the methods used in the survey work and explains the various analyses of the data gathered. Appendices give details of rare breeders as well as extra tabular data.