Wednesday, June 9, 1999 Published at 14:14 GMT 15:14 UK
Herons fly high but cuckoos crash
Best foot forward for the new brood - but the mallard is in decline
By Environment Correspondent Alex Kirby
A survey of 24 species of Britain's breeding birds shows just over half of them increasing last year.
But the British Trust for Ornithology, whose volunteers conducted the census, says the declines in some species are cause for concern.
One bird which had a good year was the grey heron, whose numbers rose by about five percent on their 1997 level. The BTO says the heron is now more common than ever before in recorded history.
Other species showing marked increases include the wren, the pied wagtail, the chiffchaff and the starling.
Robins, blackbirds and songthrushes showed smaller rises.
The trust says many of the increases may be explained by the mild winter of 1997-98.
"The rise and rise of the successful migrants, blackcap and chiffchaff, may have been based on the winter weather further south in Europe and North Africa."
It describes as "rather worrying" the losses for four long-distance migrants; cuckoo, sedge warbler, willow warbler and whitethroat.
The cuckoo, whose bubbling call is a traditional feature of the British summer, showed a 33% decline.
Overall, the trust says, "the declines are very worrying because they include several species already well known as being on the amber or red list of species of conservation concern".
And even relatively abundant birds suffered losses. The mallard declined by 10%.
Some species are in a much worse state.
"The woodcock is so rare that an annual index can no longer be calculated for it.
"The population in 1998 was barely a fifth of that recorded in 1980."
A predator, the sparrowhawk, is no longer increasing and the trust says it is "wrongly blamed for the decline in farmland birds".
It declined by 29% and is now down by about a quarter from the peak figure of five years ago.
The trust says some of its volunteers have been monitoring the same plot for 30 years or more.
"The changes they have seen in our farmland bird populations over that period have been devastating."