Although much of this report focuses on declines and their conservation significance, there are many species that are increasing in number as UK breeding birds.
In the current report, there are 21 species for which our most representative long-term trends show a statistically significant doubling in population size over periods of 20–47 years.
These are Mute Swan, Greylag Goose, Canada Goose, Shelduck, Mallard, Goosander, Sparrowhawk, Buzzard, Coot, Stock Dove, Woodpigeon, Collared Dove, Green Woodpecker, Great Spotted Woodpecker, Magpie, Jackdaw, Carrion Crow, Great Tit, Blackcap, Nuthatch and Goldfinch (in taxonomic order). Goosander and Goldfinch have been added to this list in the current report.
The 21 species that have doubled over the long term are set against the 28 that have halved in number over similar periods (see Declining species). The gap between these two totals had widened over recent years up to and including 2015, but has narrowed by three species in the current report.
Six further species, monitored only over the19-year BBS period have also more than doubled. These are Gadwall, Little Egret, Red Kite, Barn Owl, Ring-necked Parakeet and Cetti's Warbler (see Increasing species). Two additional species have more than halved over this shorter period.
For eleven species that are listed as red or amber for a population decline over the long term – Shelduck, Tawny Owl, Wood Warbler, Dipper, Song Thrush, Nightingale, House Sparrow, Yellow Wagtail, Meadow Pipit, Linnet and Yellowhammer – the decline has apparently started to level off, or has ceased, during the most recent ten-year period. Signs of recovery noted last year for Willow Warbler and Grasshopper Warbler, are no longer evident, however. While indications are positive, wide confidence intervals for some of these species allows for the possibility that their severe decline is, in fact, continuing (see Ten-year trends and evidence of species recovery).
Six further formerly declining species – Whitethroat, Dunnock, Tree Sparrow, Bullfinch, Lesser Redpoll and Reed Bunting – have reversed their population trend to show significant increases over the last ten years. Whitethroat has already been moved to the green list (BoCC4). For all these species, however, population levels remain severely depleted, despite the recent increases.