Counting birds in Britain

From British daily The Guardian:

How do you go about counting Britain’s birds? From dawn today, more than 30,000 people will go out in the field to undertake the biggest ever survey of our birdlife – a national bird census. Although they won’t have to count every single one of Britain’s 120m individual birds, it should give us a fascinating insight into the species that are thriving and declining around the country.

Known as the Bird Atlas, the data will be collected over the next four years in a series of coordinated counts in 2km-square areas of land, or tetrads. …

So which species are the likely winners and losers? In the 20 years since the last Atlas survey, birds of prey including the buzzard and peregrine, and introduced species such as the Canada goose and ring-necked parakeet, have all enjoyed population booms and expanded into new areas. There are new kids on the block, too. Twenty years ago the little egret was a scarce visitor to our shores: now it is commonly seen on the estuaries and marshes of southern Britain.

On the down side, starlings and house sparrows have disappeared from many towns and cities. Many farmland species, such as the skylark, linnet, yellowhammer and grey partridge, are also in big trouble. Others giving cause for concern are declining woodland birds, such as the lesser spotted woodpecker, willow tit and wood warbler. The latter is a summer visitor, just one of several migratory species including the turtle dove, cuckoo and spotted flycatcher, whose populations are declining.

Some could even go the way of the red-backed shrike and wryneck, both of which have vanished as British breeding birds since the original Atlas survey in 1968.