Cambridge Swift Tower


The swift tower was built in 2011 on Logan's Meadow nature reserve, by Cambridge's River Cam, and close to a new cycle/pedestrian bridge over the Cam (as reported here on BBC news). As often the case with swifts (Apus apus), it took them a while to discover the new nesting spaces, despite playing attraction calls. I've already reported elsewhere of starlings (Sturnus vulgaris) nesting in at least one of the boxes in 2013, but in 2014 swifts were finally seen entering some of the boxes (see here), and have bred every year since. Increase has been slow, but by 2018, there are at least 4 definite pairs breeding, and (as at my own house), once there are swifts present, and perhaps when birds raised here reach breeding age after around 3 years, the numbers can quickly increase.

I thought I'd do this webpage, with some of my photos, as many people still seem to say "but it doesn't have any swifts...". It does, and has for a number of years now.

Nest spaces

There are entrances to the swift nest-spaces on both the front and back of the tower, and indeed some on the sides.

If trying to describe which box you saw a swift enter or leave, we have found that the best method is to specify Front/Back/Side, and to count from the central box on either front or back, counting how many boxes east (or west), and up (or down). The central box is numbered as (0, 0). East is 'towards the river', and West 'away from the river'. Using east/west is preferable to right/left as it means that a box has the same coordinate whether you are looking at front or back. There are 17 boxes across the tower (and from top to bottom), so the maximum number east/west (or up/down) is 8. Some of the side-entrances have been used by swifts, for example "Side, East 7, Down 4" - this particular one was used by swifts in 2017 and 2018 - it's painted with a light-pink 'half-moon' in the photo below. As far as I can see in the photos (below), there is only one entrance on the horizontal and vertical lines through the centre box: the one in the middle at the very bottom of the front of the tower. If swifts ever use it, I guess we'd call it "Front, East (or West) 0, Down 8".

Front of swift tower Date: 2017 June 9

Front of Cambridge Swift Tower.

The boxes are painted different colours, and the entrances have different-shaped 'canopies' - some of these have dropped off, or the paint has flaked off, leaving a white patch - there seems to be some evidence that swifts have discovered these in preference to others that are still painted as intended!

Back of swift tower Date: 2017 June 9

Back of Cambridge Swift Tower.

The boxes are an assortment of different lengths. There are some 'slot' entrances for bats too, and although not visible in the photo, where a box overhangs the one below, there are some swift-entrances on the underside. You can see 5 of the 'side-entrances' at lower-right. The topmost of these (nearest the metal stanchion) is "Side, East 7, Down 4" (mentioned above) and used by swifts in 2017 and 2018.

Boxes in use

Information of course not guaranteed to be complete. A box is 'definite' if chicks are seen looking out; extremely likely if swifts are seen going in/out multiple times; but uncertain if only seen once (they often 'try out' boxes without using them).

The following 4 boxes were in use by pairs of swifts in 2018. There may be others, and reports are always welcome.

Box occupation was believed to be the same in 2019. In 2020, multiple in/out activity was only seen at 3 of these, with "Back, East 5, Down 4" maybe unused. In the 2021 season, by the end of June 2021, "Back, East 5, Down 4" appeared to be in use again, and new ones "Front, East 1, Down 3", and "Front, East 3, Down 5" had multiple activity, making a total of 6.

Swifts entering and leaving nests

Swift entering tower Date: 2017 July 26

Swift entering box "Side, East 7, Down 4".

Swift leaving tower Date: 2018 June 13

Swift having just left box "Back, East 5, Down 4" (the box two above where the swift is seen in the photo).

Swift entering tower Date: 2018 June 13

Swift entering box "Front, West 1, Up 4" (bottom left of photo). See photo below with chicks looking out of this box.

Swift entering tower Date: 2018 June 15

Swift entering box "Side, East 7, Down 4" (as seen in use last year above).

Swift leaving tower Date: 2018 June 15

Swift leaving box "Side, East 7, Down 4" (same box as previous photo). This swift left just 4 minutes after the one entered above. Probably a typical exchange of adult birds, whether incubating eggs, or feeding young. One adult in, other out.

Swift chicks looking out of tower Date: 2018 July 16

Two swift chicks looking out of box "Front, West 1, Up 4" (as seen above in photo a month ago with an adult swift entering). The lighter feathers on the head are characteristic of fledglings.

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Author: Clarke Brunt (
Last modified: 1st July 2021