The population status of birds in the UK (incl Channel isles & Isle of Mann) has recently been assessed in a collaborative review  involving the UK's leading governmental and non-governmental conservation organisations.

We used seven criteria to place each regularly occurring species onto one of three lists: Red, Amber or Green. This categorisation gives an indication of the relative priority that should be given to each species, and the lists will help to guide conservation efforts in the UK between 2002 and 2007.

Red list species are those that are globally threatened, whose population or range has declined rapidly in recent years (ie by more than 50% in 25 years), or which have declined historically and not recovered. Amber list species are those whose population or range has declined moderately in recent years (by more than 25% but less than 50% in 25 years), those whose population has declined historically but recovered recently, rare breeders (fewer than 300 pairs), those with internationally important populations in the UK, those with localised populations, and those with an unfavourable conservation status in Europe. 

The red list therefore reflects only the extent to which a species is threatened, whereas the amber list reflects both threat status and the UKs responsibility for bird populations. Species that meet none of these criteria are green-listed.

Of the 247 species assessed, 40 (16%) were red-listed, 121 (49%) were amber-listed and 86 (35%) were green-listed. The number of red list species has increased by four since a previous review in 1996, and the number of amber list species has increased by eleven. Of the 40 species on the red list, nine are new to this list; all of these species have been added because of declines in breeding populations. Five species have moved from the red to the amber list because their populations have more than doubled in the last 25 years. 

Several themes emerge from the new list, some familiar, some less so. Farmland birds again feature strongly on the red list, and the yellowhammer is new to this list. A suite of rare species remain red-listed despite targeted conservation action by the RSPB and others. For some of these species, like the bittern, corncrake and stone-curlew, the prognosis is relatively rosy. For others, like the black grouse and capercaillie, the outlook is bleak. Perhaps surprisingly, several widespread woodland birds now feature on the red list, indicating that there has been some deterioration in this habitat, and two urban birds, the house sparrow and starling, have been added to the red list because of long-term declines. 

  FARMLAND BIRDS

The 1996 assessments helped to focus attention on a suite of widespread but rapidly declining birds of farmed land, such as the turtle dove, the skylark and the corn bunting. It is generally accepted that these species have declined because of agricultural intensification, and in the last few years a range of schemes have been introduced to help them. All of the birds of farmed land that were on the red-list in the earlier assessments are still there. In addition, another farmland bird, the yellowhammer,  has joined them. Many red-list species remain relatively common in the countryside despite substantial declines.

  WOODLAND AND URBAN BIRDS

Birds from two new groups appear on the red-list : lowland woodland birds and urban birds. The red-listed woodland birds are the lesser spotted woodpecker, the marsh tit and the willow tit, which have declined by 73%, 50% and 80% respectively over the last 25 years. A number of other woodland species have entered the amber-list. The urban species new to the red-list are, remarkably, the house sparrow and the starling, both of which were formerly ubiquitous but have declined by more than 60%. In contrast to the situation with farmland birds, we do not know why these woodland and urban species have declined, and urgently need to find out. As with farmland birds, some of these species remain quite common despite severe declines.

  NORTHERN/UPLAND BIRDS

Several species characteristic of Scotland, Wales or northern England, such as the capercaillie and the black grouse, remain on the red-list because of continuing steep declines. Others, such as the corncrake and the white-tailed eagle, are still red-listed although their numbers are increasing due to successful conservation action. One upland bird, the ring ouzel, is new to the red-list.

  SUCCESSES

Although the overall number of species on the red list has increased since the last assessment (from 36 to 40), five species have moved from red to amber. The populations of the red kite, marsh harrier, osprey, merlin and Dartford warbler have more than doubled in the last 25 years, even though they had declined substantially previously. Much of the recent increase in these species is due to the success of targeted conservation action.