Planning and Infrastructure Bill

Lord Krebs Excerpts

Report stage
Wednesday 29th October 2025 Lords Chamber

[Lord Cromwell (CB)]

My Lords, this is Report, so I will indeed be brief. Yes, the case is well made for cavity-nesting bird bricks, and I shall just speak briefly to Amendment 138. Those who heard me in Committee will remember that I gave a bit of a treatise on ragwort. I have had endless Members come up to me and thank me for the learning they acquired; I have had only one offer to come and help me pull it out, and I thank the noble Lord, Lord Lucas, for that, in his absence.

It is not the non-native aspect that gives me a hard time. As I pointed out, roses and apples are non-natives; both come from central Asia. It is the invasive nature that is the problem, and I would love to see these EDPs and all the other acronyms have an element of responsibility for dealing with invasive and injurious weeds—injurious is the word in law—because under a lot of the current environmental schemes, you have a margin along a field which is entirely yellow with ragwort and is of very little environmental value, unless you happen to be a cinnabar moth.

[Lord Krebs (CB)]

My Lords, I rise with some trepidation to speak against Amendment 245. In so doing, I emphasise that I have the greatest respect for the noble Lord, Lord Goldsmith, and his superb work as Environment Minister in your Lordships’ House, as well as respect for the other signatories to this amendment. 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 boxes? I am absolutely in favour of measures to halt the decline in swifts and in other species I will come to in a moment; my objection to this amendment is that it simply will not work.

The amendment refers to fitting swift bricks on houses or buildings over five metres tall. 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. 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 flight path: 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: house martins, 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.

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 —swifts, house martins, sand martins and swallows—and declining insects, but swift boxes are really a bit player in this whole question. Although I support the intention of the amendment, I do not think it would deliver what is claimed and therefore, reluctantly, I do not support it.

[Lord Randall of Uxbridge (Con)]

My Lords, I am a great admirer of the noble Lord, Lord Krebs, and I listened to what he said. I remember reading a book probably by one of his predecessors at Oxford, Swifts in a Tower by David Lack, which was a very interesting and useful piece of work. I understand exactly what the noble Lord is saying. There is not a simple answer; there is the matter of insects—it is not just the hirundines and swifts that we are talking about.

Swift bricks are well-intentioned things and, of course, would not be just for swifts. There are some other cavity nesting birds including house sparrows, which may not seem as exciting to people as swifts. They are in decline; I do not see many at all around in Uxbridge now.

As my noble friend Lord Goldsmith said, the Government seem to have done a reverse ferret or had a damascene conversion in reverse, but I am still hoping there may be another one. The noble Lord, Lord Krebs, has raised the point that we should be looking at all sorts of measures, and there may be an opportunity for the Government to look at higher buildings—perhaps not residential ones, but when new schools or hospitals are being built they could put in swift bricks; they can even be put under the tiles, I believe. I hope that by the time this amendment comes to a Division, if it does, or at Third Reading, there may be some thoughts about how we make this better. I think the Government would genuinely like to do it, but there are various things getting in the way. The noble Lord, Lord Krebs, has given them a perfect excuse, so I will take him aside and sort him out.

My noble friend Lord Goldsmith and many other noble friends and noble Lords have expressed their desire for something to be done, and this seems like a good way forward. It is something for us to digest.