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| Nothing to eat, nowhere to nest - is it any wonder Swifts are in decline? |
ONE of Britain's most eminent ornithologists, Baron John Krebbs, fronted the opposition to legislation that would have - if it had been adopted - made it mandatory for housebuilders to install Swift nestbrick on buildings over five metres tall in their new developments.
In a House of Lords debate on the subject, the crossbench zoologist-peer, who, incidentally, is an expert on the territorial behaviour of Great Tits said: "My Lords, I rise with some trepidation to speak against the proposal.
"My opposition may be surprising if your Lordships recognise that I am an emeritus professor at the Edward Grey Institute of Field Ornithology at Oxford University - which is arguably the world’s leading ornithological research institute - as well as being a life member of the RSPB.
"So why am I against Swift bricks? I am absolutely in favour of measures to halt the decline in Swifts and in other species, but my objection to this proposal is that it simply will not work.
"Let me describe the basis on which I suggest that this will not work.
"The Edward Grey Institute is home to the longest-running study of Swift populations anywhere in the world: it has been running for 78 years.
"The first thing to say about this long-running study is that the Swifts nest in the tower of the Oxford University Museum of Natural History which is not five metres tall but 58 metres tall.
"I will explain why that is important in a moment - I do not want noble Lords to think that this is my opinion alone.
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| Baron Krebs:- Swift boxes are a 'bit player' |
"I consulted my colleague, Professor Christopher Perrins, who ran the Swift study for many years and is a former director of the Edward Grey Institute.
"What he points out, and I agree, is that Swifts are very specialised aerial feeders and flyers.
"They are superb flyers, and one consequence of their specialisation for flight is that in order to get into their nest, they need a very long, exposed flightpath: like a jumbo jet landing at an airport, they need a long entry point.
"Equally important, when they leave the nest, they need a very large drop space in order to come out of the nest, drop and start flapping their wings to take off.
"That is why, when nesting in the tower of the university museum at Oxford, which is 58 metres tall, the swifts prefer to nest at the very top.
"Even boxes that are 15 or 20 metres from the top are not used by the swifts; only the ones at the very top."
"This is a very well-intentioned idea, and I am all in favour of measures that will help reverse the decline in Swift populations, but I do not think this is the right one.
"So what is the cause of the decline in Swift populations in this country?
"We have to look at the fact that it is not just Swifts, but other bird species that are aerial insect feeders: Housemartins, Sand Martins and Swallows are all in steep decline. They all have very different nesting requirements.
"The swift is the only one that nests in a hole, as the Swift brick amendment would suggest, or under eaves."
Baron Krebs (80) continued: "The real cause of the decline of these bird species is the decline in aerial insect populations.
"We all know, and it is an oft-repeated fact, that in the good old days when even I was young, if you drove down a country lane at night, your windscreen would be spattered with insect corpses.
"Now you drive down a country lane at night and your windscreen is completely clear.
"Yes, we should tackle the problem of declining aerial insectivores but Swift boxes are really a bit player in this whole question.
"Although I support the intention of the proposal, I do not think it would deliver what is claimed and therefore, reluctantly, I do not support it".
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