Three swifts flying, Spain

Fulbourn swifts

The Windmill Estate in south Cambridgeshire was built in 1966 and many of the homes were in need of replacement.

About the Windmill Estate

The Windmill Estate boasted a sizeable swift population and the local community, who enjoyed their return every summer, expressed concern for the swifts during the site’s re-development.

Rob Mungovan, Ecology Officer at South Cambridgeshire District Council, tells the story.

Fortunately, planning policy now demands greater weight be attached to conserving urban biodiversity. It was agreed that conservation of the site’s swift population would be a challenge to aspire to. The birds were finding suitable nest sites in gaps between the flat roofs and using pre-fabricated wall units. Each building could offer eight or more nest sites and is probably the main reason for the large population.

Swifts re-use the same nest sites each year. Therefore, there would be much disruption to the traditional nest sites if the whole site was re-developed at once. However, it was confirmed at an early stage that a phased re-development would be undertaken. This enabled trialling and monitoring of different nest box styles.

Retaining active nests ensured existing breeding birds would encourage newly returning birds to search for unused sites and newly placed nest boxes. One of the largest challenges to conserving swift populations appears to be establishing new breeding colonies – therefore retaining breeding sites would be a primary consideration for this project.

Nest boxes for swifts

External boxes

The first trial was of external nest boxes in 2007. Many of these boxes were erected immediately above the previously closed-off nest sites. However, the birds repeatedly tried to access their former sites, ignoring the new boxes. There was, unfortunately, no confirmed breeding in these boxes, although one contained some dark feathers and possible nesting material.

In 2008, the nest boxes were relocated to allow demolition to progress. With more original nest sites blocked, more nest boxes of a different style were also trialled. Some locals reported seeing birds enter boxes, but the success of the boxes was low.

Internal boxes

The first new houses were constructed in 2009. With the bird’s reluctance to use external nest boxes during the previous two years’, it was decided to trial an internal nest box design. Seventy-five of these were provided.

Simultaneously, a further 50 external, double chamber boxes were fitted to suitable walls. To generate interest in the new boxes, swift call CDs were played to attract passing birds. As a colonial nester, swifts can become interested in sites where they believe birds are already nesting. To reduce any possible concerns of conflict between birds and residents, nest boxes were built into walls with no, or few, windows.

In 2010, it was noted swifts were already now using several of the bespoke designed internal boxes.

Commitment to swifts

The owners and main contractors have proved an ongoing commitment to conserving the swifts by providing a large number of nest boxes. They provided 125 in phase one, as well as 10 starling boxes and nine sparrow terraces.

A similar number of swift boxes are expected in future phases. It is hoped that by then young swifts will take to the various new boxes and we will have more knowledge about their specific nesting requirements.

A 2009 survey confirmed 72 active nests, making this the largest swift colony in East Anglia and possibly England. A community swift survey gave residents the chance to learn more about swifts and to understand the various measures being used to help conserve these wonderful birds.

Thanks to early consideration, South Cambridgeshire District Council was able to work closely with the planners and owners to not only safeguard the swifts, but also to increase the population. The estate has now been re-named as 'The Swifts', demonstrating how species conservation can be good for the local community and housing associations alike.

In 2011 the Fulbourn Swifts Group was established and they have carried out community swift surveys on the Windmill Estate/Swifts Development since 2012. Their nestbox monitoring results can be downloaded on the right. The last houses on the re-development were completed in autumn 2014 so there should now be more than 270 swift nest boxes on site.

Swifts flying over rooftops

Fulbourn swifts

Rob Mungovan, Ecology Officer at South Cambridgeshire District Council and Gemma Rodgers discuss how important the safeguarding of swifts was during the re-development of The Windmill Estate in south Cambridgeshire.

Rob Mungovan, Ecology Officer at South Cambridgeshire District Council and Gemma Rodgers discuss how important the safeguarding of swifts was during the re-development of The Windmill Estate in south Cambridgeshire.

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Fulbourn swifts video screenshot