Comparison of habitat-specific trends in the abundance of breeding birds in the UK

Capsule Trends in the relative abundance of 18 out of 23 breeding bird species of conservation concern varied significantly between habitats. Aims To produce and compare habitat-specific trends in abundance of widespread breeding birds of conservation concern in the UK. Methods Breeding Bird Survey data for 23 red- and amber-listed species were compared across 12 habitat categories. Habitat preference indices were calculated for each species and population trends were compared between favoured and avoided habitats, with the expectation that declines would be greatest in avoided, assumed poorer-quality, habitats (the buffer effect). Results Over 75% of species showed significant variation in trends in abundance across habitats. In some species the annual rate of change differed by more than 10% between habitats. There was no consistent relationship between the trend of a species within a habitat and its preference index for that habitat. Conclusions The rate at which species of conservation concern are changing in abundance varies between habitats. Some species are declining more quickly in preferred habitats, others in avoided habitats, showing little consistent support for the buffer effect. Habitat-specific trends should be considered when deciding how best to focus conservation efforts.