birding-aus

Swifts in the news

To: Birding Aus <>
Subject: Swifts in the news
From: Laurie&Leanne Knight <>
Date: Mon, 17 Jun 2002 19:09:07 +1000
I'm sure someone will quickly point out what species of swifts are being
referred to here.

Not sure the causal factors discussed in the sparrow segment are plausible ...


http://news.independent.co.uk/uk/environment/story.jsp?story=305398

Falling swift population blamed on 'better' roofs
By Brian Unwin
15 June 2002

>From a hilltop village in the south of France to the south London suburbs,
readers of The Independent have been asking the same question this damp and
disappointing summer: "Where have all the swifts gone?"
The absence of the familiar wheeling clouds of birds has been vexing the letters
page of this newspaper for the past two weeks. To ornithologists the explanation
is clear and sadly familiar. Man is again to blame.
The swift population has declined by more than 75 per cent in 15 years, almost
entirely because old buildings have been demolished and ancient roofs replaced.
Ever since man first set up home, this most aerial of birds has enjoyed the
advantages of moving in alongside.
Originally flying north from Africa to rear their young in Europe, they chose
lofty ledges on cliffs and crags. However, that ended some time after humans
became capable of erecting taller, more elaborate buildings. It is believed the
swifts were using the eaves of buildings in Britain by the Middle Ages and their
population boomed with the large-scale spread of construction from the 19th 
century.
But over recent decades the process has been thrust into reverse as "improved"
building techniques have made it harder for swifts to gain access to the point
where walls meet roofs and provide them with homes. With progressively fewer
places to nest, the population has been falling.
Chris Mead, a British Trust for Ornithology (BTO) consultant, said: "The problem
is the PVC soffits that are being put up around eaves and prevent swifts from
reaching the wall plate, where the brickwork meets the roof. This can be
remedied by a small hole being cut in the soffit where it meets the wall."
Another solution is to put up a special nest box, either under the eaves or
built into the soffit. Swifts can also be encouraged by playing tapes of their 
calls.
This year the weather has been too cool and too wet to allow young returning
swifts to build in numbers and look for sites for when they start nesting in
years to come.
Mr Mead said: "What particularly makes people notice flocks of swifts is their
screaming calls." He said the young birds were mainly responsible for the noise.
"If we enjoy a sustained warm spell as the summer advances we could start being
aware of a lot of swifts screaming overhead ? we certainly haven't lost this
spectacle altogether."
Some experts said swifts could still be seen. In April this year, during the
spring migration, more than 3,500 birds were counted passing over Chew Valley
Lake in Somerset in little more than two hours. Dawn Balmer, who is running the
BTO's migration watch project, said: "Whereas swallows came trickling in over a
period, there was a sudden big arrival of swifts in late April. Also the poor
weather subsequently led to them concentrating over lakes and reservoirs, where
there was better feeding. As a result it has taken some time for numbers to
increase in built-up areas where they nest." Bad weather over Spain and Portugal
during the migration period had caused a hold up in the northward flight of 
swifts.
This is also the case with that other favourite summer visitor the house martin.
Ms Balmer said the birds were now back and had started building their mud nests.
She said the spring needed to be just right for house martins. "If it is too dry
they cannot find the soft mud they need. This year that should not have been a
problem in most places but the cold weather will have limited their supply of
insect food."
* A leaflet on how to help provide swifts with nesting sites can be obtained by
sending a stamped, addressed envelope to Chris Mead at The Nunnery,
Hillsborough, Thetford, Norfolk, IP26 5BW.

Where have all the sparrows gone?
The Independent has already done much to highlight the plight of the house
sparrow. Its campaign to save the bird has drawn attention to a genuine mystery
in the natural world: something catastrophic has happened in the ecosystem of 
British
urban sparrows, but what? And if it is harming sparrows, might it be harming
human city dwellers?
The many possible culprits named in hundreds of letters from readers range from
magpies, sparrowhawks and cats, to peanuts, pesticides, home improvements and
climate change.
The ornithologist Max Nicholson thinks it may be due to a "suicidal tendency"
which makes flocks break up and cease breeding once they fall below a critical 
number.
Dr Denis Summers-Smith has pointed out that the steep decline has coincided with
the introduction of unleaded petrol.
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