Friday 20 February 2015

Fulbourn Community Swift Survey 2014

The nest boxing project at the 'The Swifts' housing estate in Fulbourn, Cambs is probably the largest and most successful in the country. You can read background information in Fulbourn Community Swift Survey 2013 and Fulbourn Community Swift Survey 2012. This report brings things up to date for 2014.

Contributed by John Willis

This was another successful year for the Fulbourn Swifts Group – our fourth year of surveying in the village. Our main focus was again on surveying swifts around the new houses of The Swifts Development, which was approaching completion, but also we were able to do some monitoring of the small colony located at St Vigor’s Church including undertaking some point counts for the RSPB. 

It was a great summer for the swifts with a substantial increase in observed nest box use and in our estimated number of breeding pairs thanks to the continued popularity of the internal boxes.

We met on site at 'The Swifts' every Wednesday evening between 7 May and 27 August, and individuals made observations on many other evenings during the summer as well. With 23 people active in the survey we had an average of 8 observers each Wednesday. As in previous years, several local residents reported observations made from their own homes.

To raise awareness of swifts in the village ahead of the swift season we published articles in the Parish Council Newsletter and the Parish Magazine and we distributed a flyer to all homes on the Swifts Development.  At the end of May we organised a coffee morning and swift display at the Community Library where we had support from Action for Swifts – Judith Wakelam provided photographs and display material and Bob Humphrey brought nest boxes. Also we mounted displays at The Fulbourn Community Market and the Fulbourn Feast in June and a few new people were recruited to the group.

On the Swifts Development an estate of 1960s system built houses, which had become home to a large colony of swifts (72 breeding pairs in 2009), has been demolished and replaced by new homes with provision of swift nest boxes. 

John Willis with an internal nest box.
Photo © Rosemary Setchfield
The boxes are of two types; internal custom made wooden boxes incorporated in the house timber frames in gable ends (see design here), and external Schwegler 1MF double boxes fitted on gable ends in phase 1 and on front/rear elevations in phase 2. The photograph shows the structure of an internal box prior to incorporation into the timber frame of a house. The plastic pipe is cut flush with the external brick wall.

At the start of the swift season, work on the final part (Phase 2b) of the Development was well under way with a number of houses having been completed over the winter.  This added another 20 internal and 10 external nest boxes bringing the total on the site up to 159 internal and 98 external – it was quite a challenge for us to successfully monitor all of these!

Our first swifts of the season arrived a little later than usual on 5 May and during the month there were decent numbers flying overhead but with relatively small screaming parties. 

Activity increased significantly at the beginning of June with an influx of prospecting young birds and with the generally good weather there were spectacular flying displays with large screaming parties throughout June and July. Peak numbers of 70+ were seen on 23 July with low level screaming parties of up to 20 birds providing a wonderful spectacle. Numbers started to decline around 27 July and by the beginning of August there were no more than 20 birds flying overhead and with virtually no screaming parties.  We were aware of 8 nest boxes still being used in early August and one pair were feeding young right up to 1 September.

Swift leaving an internal nest box
Photo © Judith Wakelam
This year, swifts were observed using 102 out of 159 internal nest boxes, 8 out of 98 external nest boxes and 4 sites in the one remaining old block – 114 sites in total. This represents a substantial increase on the 80 sites observed in 2013.  We estimated that there were 78 potential breeding pairs – 72 in internal boxes, 4 in external boxes and 2 in the old block. The corresponding estimates of potential breeding pairs for 2013 and 2012 were 58 and 32, so it appears that the colony is making a rapid recovery following the demolition of the old nest sites.  With 36 other sites having been prospected during the summer there is optimism for further growth in the number of breeding pairs in 2015.

The increase in activity comes from the third phase of the development (2a), which was part completed for the summer of 2012 and which the birds first colonised in 2013.  This area includes a high concentration of internal boxes (76), which are mainly in groups of four located on gable ends of houses and 3 storey blocks of flats – birds were using boxes in both types of location. Table 1 shows the history of occupancy.

Internal boxes
% occupied23.42%36.69%45.28%
Schwegler 1MF
% occupied2.17%3.41%4.08%
% occupied17.20%23.79%29.57%
Old buildings
Grand total
Table 1: Summary of nest box activity 2012 - 2014.
Encouraging positive trends.

The major preference was again for the internal boxes with just one additional breeding pair using the external Schwegler boxes this year.  We have previously noted the presence of starlings in some Schwegler boxes but we have not observed any direct interaction between starlings and swifts. During April we walked the site on a number of evenings to assess the use of the external boxes by starlings and we were surprised to find that the starling population appeared to be relatively low.  We saw birds using 15 of the 98 external boxes and 2 of the 159 internal boxes and we heard evidence of young in just 5 of the external boxes.  We observed starlings using all four of the external boxes in the photograph below, but there was no evidence of young present.  Subsequently swifts nested in both of the top boxes for the second season running.
Schwegler 1MF external boxes
Swifts nested in the top boxes
So it appears that starlings are having little impact on swift use of this type of box. At the same time we noted sparrows using at least 9 internal boxes – nearly all of these boxes were subsequently used by swifts.

The builders have now completed the last houses of the Swifts Development so for the 2015 swift season there will be another 20 nest boxes available and we will have the task of monitoring over 270 boxes!  We will continue with our publicity within the village to maintain awareness of the project and to ensure that we have good participation in the 2015 survey. If any Fulbourn residents reading this would be interested in putting up a nest box or taking part in the 2015 survey, then please contact us at 

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