Wednesday 7 November 2012

Fulbourn Community Swift Survey 2012

The provision of Swift nest boxes in Fulbourn to mitigate the loss of 72 pairs of Swifts in 1960's buildings, scheduled for demolition, is probably one of the largest such projects in the country. It is also headed towards being one of the most successful. In 2012, 157 new nest-boxes were occupied by 27 pairs of Swifts, alongside 5 of the original nest-sites. 

Contributed by John Willis 

The Fulbourn Community Swift Survey was organised by the local swift group, which was formed in 2011. Our focus this year was on the 'Swifts Development' where an estate of 1960s system built houses is being demolished and replaced by a higher density of new homes in a phased programme. These old buildings had become the home for a large colony of swifts and provision is being made for both internal and external swift nest boxes in the new houses. You can read background information in Swifts in Fulbourn, Cambridgeshire and this RSPB case study.

Old houses with stopped up nest sites
where the panel joints meet the roof boards 
It was hoped that our community survey would complement the official survey to be undertaken by Applied Ecology Limited, who have been monitoring the colony since 2009, and help increase awareness of the swifts among the local residents.

We met on site every Wednesday evening from 9 May to 15 August. Individuals made observations on other evenings during the summer, especially when the weather was warm! One of the residents was a regular member of our team and many other local people approached us on survey evenings to ask about the swifts. We often received useful reports of birds using specific boxes and all feedback about the swift project was very positive.

Potential nest sites on several blocks of old houses, which had been used for breeding in 2011 (20+ nests reported by Applied Ecology Ltd), had been sealed with foam prior to the arrival of swifts. However, one remaining block of 5 houses (2 nest sites recorded by Applied Ecology in 2011) will not be affected by re-development, and the nest sites there were available to swifts this year.

With 157 swift boxes already installed on the site it was quite a challenge for us to adequately monitor all areas. The boxes are of two types; internal custom made wooden boxes (111) incorporated in the house timber frames in gable ends, and external Schwegler 1MF double boxes fitted on gable ends in phase 1 and on front/rear elevations in phase 2.

Internal wooden nest boxes are
built into the house timber frames 
The first swifts of the season were seen over the Development on 30 April with a group of up to 12 birds flying over the old buildings at the west end of the site. The numbers steadily increased reaching a peak on 11 May when there were up to 50 birds forming into screaming flocks and moving around rapidly. Numbers flying in the evening fluctuated over the following weeks but there was a distinct increase in activity from 18 June. A spell of milder weather from 17 July heralded a further increase in the level of activity with some great flying displays. Peak numbers were seen on 23 July, a warm evening, with over 50 birds flocking overhead and screaming parties of up to 20. The last large group of 35 was seen over the site on 3 August and after that the numbers steadily declined with the last sighting of the year being a pair of birds flying over the centre of the site on 20 August.

In phase 1 of the building development, which comprises phases 1a and 1b referred to below, 40 out of 63 internal boxes were used at some point in the season by swifts compared to 4 out of 22 external boxes. Of these, 26 internal boxes and 1 external box were used regularly enough during the season for us to suspect nesting activity.

We observed regular use of 15 out of 18 internal boxes in phase 1a, which has been colonised by swifts since 2009, whereas the corresponding figures for phase 1b, which was completed prior to summer 2011 but with no confirmed nesting, were 11 out of 45. The one regularly used external box was also located in phase 1a. It is encouraging that swifts now appear to be colonising the more recent phase 1b and hopefully the numbers there will increase over the next few years.

These unmodified Schwegler 1MF boxes
are very popular with starlings 
The external Schwegler boxes were clearly not favoured by swifts, but possibly this is because so many starlings were already in residence by the time that the swifts arrived.

Prior to installation, we modified the external Schwegler boxes in phase 2 to restrict the entrance size to deter starlings, but we did not observe any birds using them. You can read more about the background to this in Fulbourn Update.

Early in the season a group of swifts were observed flying close to the four internal boxes on a recently completed house in phase 2. Subsequently, site workers reported that they had seen swifts enter boxes nearby. However, despite observation of these locations over the summer on a good number of evenings we never managed to record a swift entering a nest box in that area. There were often swifts overflying this latest phase of the development, so hopefully some of the 72 swift boxes (including both types) already installed have been ‘checked out’ for use in the future.

The one remaining old block of houses was a focus for swift flying activity throughout the summer and we regularly observed birds accessing 5 nesting sites under the boards on the edge of the flat roof and occasional activity was observed at 2 other locations.

Swifts started using internal boxes in the
narrow gaps between some of these new houses 
We do not know whether there was successful nesting and rearing of young at any of the regularly used sites. However, it is encouraging that the number of these sites (32) was similar to the number of nesting places identified in the official 2011 survey undertaken by Applied Ecology Limited, especially given that around 20 nest sites in the old blocks were not available this year and there were big reductions in the number of nest sites used in each of the previous two breeding seasons.

During the summer there was a very positive response and useful input from the residents of the site and we aim to build on this for the 2013 Community Swift Survey.

We would like to thank Rob Mungovan, South Cambridgeshire District Council Ecology Officer, for his support and encouragement.

If any Fulbourn residents reading this would be interested in putting up a nest box or taking part in the 2013 survey, then please contact us at


  1. Well done! (your superb work as depicted on BBC Urban Jungle). How can we get councils to heed the importance of bird niches and boxes? Herts and Essex hospital sadly was demolished and the old buildings "converted" into dwellings. I wrote to the council asking what will now happen to the swifts; but my correspondence was ignored so no swifts observable Why are many supporters of wildlife ignored as cranks? [Creator's wonderfully evolved nature (and we too) will cease to exist by our hands; the stewards tasked to care for it].Can you initiate a national process of geting bird nesting sites incorporated into building regulations (even after the birds, such as the house martins who avoid plastic guttering, have left our locations)?

    1. You need to contact the Biodoversity officer, or the Nature conservation officer - many councils have someone for this.