Friday 4 October 2013

Modifications to Cambridge Swift Tower

This year, summer 2013, was the 3rd year of trying to entice Swifts to occupy the Cambridge Swift Tower. We upgraded the attraction call player to a higher quality, louder, system based on the Cheng Sheng player amplifier, powered by a 12 volt car battery charged with a 20 watt solar panel.

Written by Dick

In 2011 and 2012 we played attraction calls using a bird scarer programmed with Swift calls. The sound quality was not great and, in 2012 particularly, proved to be quite unreliable. However, in both years, we had Swifts circling the tower and sometimes approaching quite close to the boxes.

In 2013 we progressed to having Swifts making contact with the boxes, sometimes clinging on, but still failng to find the entrances. They seemed to be focused on trying to get into the horizontal gaps between the boxes, where there was no way in. 2 pairs of Starlings also occupied boxes in the tower, probably because the entrance sizes had crept above 30mm.

The back of the tower, showing some boxes
extending beyond the box below
Of the 221 boxes in the 'African Sun', 88 had entrances for Swifts and 10 had entrances for bats. There were also 36 unassigned boxes which extended beyond the box below. Thus we could add a whole new class of entrance in these boxes, by cutting a hole in the underside of the rear.

We have succeeded in making this enhancement in 9 boxes so far, increasing accommodation for Swifts to 97 boxes, without affecting the appearance of the tower at all. We hope these new entrances are similar to what Swifts are accustomed to in natural sites. A nest concave was placed in all of these new boxes.

You can see the current assignment of the nest boxes here.

The project team was:
Guy Belcher, Clarke Brunt, Alan Clarke, Bill Murrells, Dick Newell and Bob Tonks


  1. When I passed the swift tower yesterday I noted a lot of bird poo at the top. Does this indicate swifts have moved in this season? (I no longer live nearby so haven't been watching.)

    1. There is a small number of Starlings breeding in the tower. As last year (2013) Swifts have been seen taking a keen interest in the tower, but we have no reports of occupancy yet.