BBC Nature 19 Nov 12;
The UK bird population has declined by 44 million since 1966, according to a report by conservation groups.
The study is the first of its kind to give an overall view of how birds in the UK have fared over the decades.
It found that while certain species had increased in number, populations of some common birds had diminished dramatically.
The report, "State of the UK's Birds 2012", was compiled from volunteers' observations of birds since the 1960s.
According to the report, carried out by experts from organisations such as the Royal Society for the Protection of Birds (RSPB) and the British Trust for Ornithology, there are an estimated 166 million birds nesting in the UK compared with 210 million in 1966.
House sparrows were found to be among the worst hit, with numbers down by 20 million compared with the 1960s.
Since 2000 a modest increase has been reported in sparrow numbers, but causes of the overall decline of the bird population remain unclear.
"It's like the bird populations of the UK are on a roller-coaster, and we've seen a lot of ups and downs," said RSPB spokesperson Grahame Madge.
"We have more species breeding in the UK now than any other time in history... but we've got 44 million fewer individual birds nesting than in the 1960s."
Birds that are reliant on farmed land, such as lapwings, cuckoos and turtle doves, have seen a significant decrease in numbers, according to the study.
Experts believe this is largely down to changes in landscape providing less habitat in which birds can feed and nest.
"But what we're seeing at the moment is a huge interest from farmers in trying to help the wildlife on their land," added Mr Madge.
"We know... that some species like wood pigeon and collared dove have done incredibly well and increased their populations," commented Mr Madge.
The wood pigeon has doubled its population since 1970, to an estimated 5.4 million nesting pairs.
Another example of a bird doing well is the great spotted woodpecker.
Mr Madge explained: "Many of our woodland birds are in trouble but great spotted woodpeckers have gone up 368% since the 1970s, which is an incredible increase."
But Mr Madge went on to say that despite such success stories the overall findings of the report were of concern, and that the report had allowed experts to appreciate "the enormity of the decline".
"When you see en masse that the UK has lost such a huge number of birds, the figures themselves are quite staggering," he said.
BBC Nature 19 Nov 12;