The RSPB, Calderdale Council and Openreach have fitted 120 swift nest boxes across Calderdale in West Yorkshire, the charity announced on 1 September. The birds the boxes were built for have already left for Africa and will not be back until late spring.
The new boxes went up on houses, businesses and community buildings, including sites in Halifax, Luddenden and Hebden Royd and at the Eureka children’s museum. They take the total created through the Calderdale project to 180. This was the second year of the scheme, championed by Calderdale Council and funded by The Community Foundation for Calderdale.
Nat Le Brun, an RSPB senior conservation officer, said in the RSPB’s announcement that the project “has been a brilliant way to engage with local people and explain why our Swifts are under threat”, and called it “a beautiful example of the Calderdale community coming together”.
Why a bird that barely lands needs a building
Swifts are almost entirely aerial. They feed, sleep and mate on the wing, and the nest is the one thing that brings them down onto a solid surface at all. An adult weighs 36 to 50 grams and can reach 69 mph, which the RSPB says makes it the fastest bird in the world in level flight.
What a swift needs from us is a hole. They nested traditionally in gaps under roof tiles and in the eaves of older buildings. Renovation, demolition and insulation have sealed most of those gaps, and modern construction rarely leaves new ones. Buildings are also where the other big hazard sits, which is why it is worth knowing which glass treatments actually stop birds hitting windows.
The decline shows up in two figures, and the RSPB’s own pages do not quote the same one. The Calderdale announcement puts the fall in UK swift numbers at 62% since 1995. The charity’s species spotlight for swifts cites the Breeding Bird Survey and puts it at 70% between 1995 and 2024. Both point the same way. The species was added to the UK Red list of Birds of Conservation Concern in 2021.
A percentage hides the part that matters most on a single street. Once a pair has settled on a nest site, they return to that exact site every year. If it has been rendered over or knocked down while they were in Africa, the RSPB says the pair can spend a whole breeding season searching for a replacement rather than raising chicks.
Why the work happens in September
Swifts arrive back in the UK in late April and May after a journey of more than 6,000 miles from central and eastern Africa, which they make twice a year. A box fitted in early September has eight months to sit quietly in place before anything looks at it.
That is the whole logic of the timing. Nobody installs a swift box for this summer. They install it for the birds that arrive on the warm days at the end of April — the same first warm days that get pet birds lost when a window goes open without anyone thinking about it.
What you can do, and the safety rules that come with it
The RSPB’s guidance on nest boxes for buildings is blunt about the practicalities. Get the building owner’s permission before anything goes on a wall. Boxes go up high, usually off a tall ladder, so check that whoever installs them has the relevant insurance. And never site a box above a door, a path or any other high-traffic spot, in case it comes down.
The charity’s community projects also work street by street rather than house by house, which is why they are called swift streets. A single box on a single wall is a smaller bet than a cluster of them along one road.
If you want to help without drilling into anything, the RSPB asks people to record swifts screaming at roof height, or entering and leaving nest holes, through Swift Mapper. Those records are what local groups use to protect sites that already exist. The window for that is next May to July, not now.
Food is the other half of the problem. The RSPB names declining insect abundance alongside nest-site loss as a key driver, and asks people to plant a diverse range of native, insect-attracting plants. That sits alongside the RSPB’s other change to UK garden feeding this year, and it is closer to what actually brings more birds into an outdoor space than any single feeder ever is.
Calderdale had a twenty-year head start
The requirement for swift bricks on new builds came into force in the Calderdale Borough Council area in 2004, and the council has run spot checks on new developments since to make sure it happens. Swift bricks are built into a wall rather than hung on it, with the cavity inside the brick.
That local rule is now catching on nationally. In January 2026 Scotland became the first UK country to write swift bricks into law. The brick design itself came out of an RSPB collaboration with Barratt-Redrow, formerly Barratt Developments, and Manthorpe Building Products.
Calderdale is not the largest of these schemes either. The RSPB’s Manchester Swift City project has created 11 swift streets and installed more than 230 boxes, many of them built by local college students. Openreach engineers had put up 101 swift boxes across the UK on employee volunteer days as of April 2026.
None of it is visible yet. The measure of whether 120 boxes in West Yorkshire worked is a sound in the third week of May, and nobody involved will know until then.
Featured photo: a common swift (Apus apus) in flight at Gennevilliers, France, by Alexis Lours via Wikimedia Commons, CC BY 4.0. It is not a photograph taken in Calderdale.