Wednesday, 31 May 2017

Swift boxes at the David Attenborough Building

The David Attenborough Building (DAB) in Cambridge houses conservation practitioners and academics, who are working together Cambridge Conservation Initiative (CCI).

"The David Attenborough Building will act as a collaborative hub for the conservation community within Cambridge and beyond - Mike Rands"


It had always been the ambition of the executive director, Mike Rands, to have breeding Swifts, so AfS was invited to see what might be possible. As all the building work had been finished, this was a retrofit situation on a very smart building that we would not want to compromise in any way.

Two opportunities presented themselves: boxes installed at the top of one of the towers and boxes on the parapets. As the former would be less visually intrusive, Mike suggested we go for the towers.

The tops of the towers are octagonal with vertical bars containing 4 of the sides. The bars are 50mm wide and spaced 50mm apart (see pictures below).


John Stimpson supplied 8 Model 30 nest boxes, but with no entrance in the front. This was a suitable choice as the top of the tower is exposed to the sky, so the boxes may receive both rain and sun.

For the Swifts to gain access to boxes inside the bars, it would require tunnels about 15cm long to the outside.

We have some anecdotal evidence that Swifts will not negotiate a small tunnel of this length (e.g. here). Thus we made tunnels with inside dimensions 43mm wide x 65mm high.

A D-shaped hole was cut in the back and tunnels fashioned out of roofing plastic glued in place.

Roofing plastic put into boiling water is easy to shape around, in this case, an empty can of hairspray.

Rubber strips provided separation and friction between the boxes and the metal bars.

The tunnels could also provide access for Starlings, so the top part of the tunnel is blocked on the inside face of the box. This should leave enough space for a Swift to enter, but not a Starling. One of the concerns was not to have bird droppings down the building.

The brackets, made of stainless stud and aluminium bars, were made by Dexter Bullman of Landbeach. They were painted to match the vertical bars.

A Cheny Heny MP3 player was installed driving 2 tweeters facing outwards below 2 of the tunnels. We gave some thought to the possibility of Swifts coming through the bars, but as the space is open to the sky, they should be able to get away.

The pictures below illustrate what was achieved:

4 tunnels outside the SW side and 4 boxes inside the SE side
Close up of the 4 tunnels on the SW side

Installation team: Bill Murrells, Elizabeth Allen, Collaborations & Communications Manager,
Dexter Bullman and Mike Rands, Executive Director.
Dick Newell took the picture