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Buildings and structures

Many structures along our waterways are over 200 years old and play an important, but often overlooked, role in biodiversity.

Picturesque image of Brecon Basin through a bridge. Sunny day with pretty houses next to the canal.

What is a building or structure?

Bridges, tunnels, pillboxes, locks, weirs, cottages, warehouses and offices all count as a building or structure, and provide valuable habitats for wildlife.

A wealth of life unfurls from the nooks and crannies, making the most of the damp conditions and shaded areas.

  • Read the video transcript

    Now, thinking of canals and bridges and things. I mean, a lot of this infrastructure was put in during the Industrial Revolution and everything like that, carrying really important goods and stuff into the hearts of cities. But actually, you know now, it’s been taken over by wildlife, and it’s amazing to see what moves in when you give it the chance to.

    Yeah, absolutely. I mean these canals, some of them are 200 years old, even more in some cases. And these structures, like this really old bridge behind us, have been here for hundreds of years, giving wildlife plenty of time to make their own home out of that structure. Something like this bridge, you could have bats roosting up in the gaps, cracks, and crevices. You could have birds nesting in some of the holes. Sometimes, reptiles and amphibians might come out and bask in the grass that’s growing over the top of the bridge; just a fantastic habitat.

    It’s just so important isn’t it? Something that could be deemed as kind of a man-made structure. Something that, you know, we’re the only species that gets any use out of it. But when you look in the details, you look in those cracks, and you see a bat, you know, hibernating or in torpor in there towards the end of the spring season, or you see those invertebrates, you realise just how important those structures can be if we give wildlife the chance to move back in.

    Absolutely, yeah, I think that’s right. And it’s those structures that animals can then make a home of, even in the really urban city centres. We’ve got some pillboxes along some of our canals that we’ve prevented people from being able to get into because, sadly, they were just using them like giant litter bins. But we’ve created habitat inside them for bats to come and move in. And so that will hopefully give the bats a really safe and secure, temperature stable place that they can move into, right in the heart of our city centres.

    I love that, and I love bats as well. I love to see, you know, more bats around the city centre. I mean, I live in central Southampton, and I don’t get to see many, other than when I go to the outskirts in the New Forest and such. And it’s such a shame, and we’ve just got to learn to be more tolerant and share our space with the wildlife.

    Absolutely, I mean, the canals are a fantastic super highway for bats. There’s everything they need. They’ve got shelter from the trees and the hedgerows on either side. They’ve got ample food, foraging over the water surface. And then those waterways come right into the city centres. But they also, in the opposite direction, can go quite into really rural areas where there are woodlands and places that bats are going to be roosting. It’s just a great super highway.

Who might live in buildings, bridges, locks and walls?

Bats are probably the most well-known animals that use our structures to rest and roost. They can sometimes be seen clustered in tunnel roofs or under aqueducts, but usually prefer to be hidden in crevices.

Canal structures are particularly important for bats because of their waterside location, which provides a rich variety of insects on which they depend.

Invertebrates that like dark and damp spaces will also be drawn to these areas, as well as amphibians that rely on cool spots to bask and regulate their body temperatures on hot, sunny days.

Bird species to look out for are grey wagtails and nesting house martins.

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Last Edited: 31 March 2025

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