Changes in the Fulflood Swift Population from 2018 to 2026
Updated: 3 days ago
Fulflood in Winchester has long been an important breeding place for swifts. It is an area characterised by large numbers of Victorian and Edwardian terraced houses. Many of these houses used to have places for swifts to nest in gaps under the eaves, under the barge boarding on gables or at the edge of the roof on dormer windows. When we first surveyed Winchester for nesting swifts, we found 27 such natural nest sites in use in Fulflood.
Over the last eight years, the number and type of nest site available for Fulflood’s swifts has changed markedly. During our surveys of Fulflood in 2022 and in 2026, we found fewer swifts using natural nest sites than in 2018. We may have underestimated how many such sites were being used. Some known natural nest sites are not visible from the road so we had to rely on residents’ reports of whether swifts were using them. It is easy to miss seeing swifts enter and leave their nests as they do so at great speed and very discreetly. However, the main reason for the reduced number of swifts we found nesting in natural sites is that there are fewer such sites available for them to use. When original timber soffits and fascias are replaced with uPVC versions, for example, the gaps under the eaves that allow swifts (and other cavity-nesting birds) to access a flat place to make a nest vanish. Similarly, replacement of roofing material on the dormer windows that are a feature of many of Fulflood’s houses seals off gaps where swifts could find a space to rear their chicks. Fortunately for the swifts, the loss of natural nest sites has been accompanied by a large rise in the number of swift boxes installed. As a result, in 2026, of the 58 occupied swift nest sites found, 51 (88%) were in nest boxes. By comparison, in 2018, of the 30 occupied swift nests found, only 3 (10%) were in nest boxes. When the overall totals for 2026 and 2018 are compared, our figures suggest the number of pairs of breeding swifts in Fulflood has increased by 93% since 2018. This would not have happened without the installation of multiple nest boxes.
Ever since our first survey of Fulflood in 2018, the swift nest sites have been concentrated in just a few roads. The two roads with by far the largest number of nesting swifts are Elm Road and North View. Both roads contain multiple nest boxes, a testament to the enthusiasm many residents feel for their swifts. To read our previous blog on the swifts in these roads, see here. On fine summer evenings in June and July these two roads are a wonderful place to experience big swift screaming parties, watch young non-breeding swifts investigating nest sites, and be enthralled by spectacular aerial displays.
Over the last two years we have installed several swift boxes in Fordington Avenue and Fairfield Road and six double swift boxes at Peter Symonds College in Owens Road. None of these boxes seem to have been occupied by swifts so far. But the use of a call player at Peter Symonds College has attracted swifts to investigate the boxes, so we are hopeful that swifts may nest in some of them next year.
This year nearly all the available nest boxes in Elm Road and North View were occupied by swifts: they were seen using 20 of the 21 boxes in Elm Road and 20 of the 26 boxes in North View. Unless more nest boxes are installed in these roads, swifts will soon have to look further afield to find places to nest. There are several roads in Fulflood where none or very few of the houses have nest boxes, even though they would be suitable sites for swifts. I am planning to distribute some flyers about swifts’ need for nest sites and our swift box installation service, stressing what excellent neighbours they are and what excitement and joy they bring to a street. We hope that many more Fulflood residents will decide to share their home with swifts.
Catharine Gale, Hampshire Swifts
Acknowledgements: We are very grateful to Pete Carty, Carrie Carty and Daria Dadam for their help surveying Fulflood’s swifts in 2026 and to Fiona Hartley for her help surveying the swifts in 2022.
