2025 Update on the Swifts Nesting in Highcliffe, Winchester

Highcliffe is one of the areas of Winchester that we survey for nesting Swifts every year.   This suburb is made up of two large areas of housing built by Winchester City Council for rent, mostly between the two World Wars, with a substantial number of houses dating from the late 19^th and early 20^th centuries, much of it terraced. As in so many urban areas, opportunities for cavity-nesting birds such as Swifts, House Sparrows and Starlings to breed in gaps or crevices in buildings have drastically diminished here as houses have been renovated, re-roofed or had uPVC soffits and fascias installed.  After discovering in 2018 that nest sites in Winchester City Council’s Highcliffe houses were being lost in this way, we came to an agreement with the Council that all tenants would be offered a swift box when their house had such work carried out. This arrangement, along with interest from other residents in helping Swifts, has so far resulted in 128 swift boxes being installed. Every summer since 2020 we have surveyed Highcliffe to assess how many of these boxes are being used by Swifts. To read our 2021, 2022, 2023 and 2024 blogs about Highcliffe’s Swifts click on the links.  

Since regular surveying began in 2020, the number of Swift pairs occupying boxes has risen every year. 2025 is no exception, with an increase in the number of Swift pairs nesting in boxes of just under 40% since 2024. Numbers have risen from 14 pairs of Swifts in 2020 to 60 pairs in 2025 (see figure).

The majority of Highcliffe’s Swifts nest in boxes in two roads, Portal Road and Gordon Avenue. Of the 38 swift boxes in Portal Road, 23 had Swifts nesting in them this summer.    Of the 48 swift boxes in Gordon Avenue, 29 were occupied by Swifts. The large number of nesting Swifts in both roads meant that many younger, non-breeding Swifts were attracted to those areas, resulting in very large parties of screaming Swifts hurtling low over rooftops, particularly on fine evenings. It was a thrilling spectacle. One resident estimated that sometimes there were around 40 Swifts in such screaming parties.

Although most Swifts currently nest in the boxes in Portal Road and Gordon Avenue, this year there were four pairs occupying nest boxes in Milland Road, one pair in St Catherine’s Road and one pair in Nelson Road. Swifts have also started colonizing the boxes in Vale Road, with two of the 8 boxes here occupied this summer for what we think is the first time.

There are a few roads in Highcliffe where only one or two swift boxes have been installed. Most of these boxes are some distance away from any occupied swift boxes. These more isolated boxes are taking far longer to be adopted by Swifts than the boxes in Portal Road or Gordon Avenue where Swifts can be certain of having other Swifts nesting nearby.  One swift box in Portal Road was installed on 31^st January 2025 and by early June Swifts were seen nesting in it!  The yearly increase in the number of Swift pairs occupying boxes in these two hot spots in Highcliffe is partly due to the number of boxes available there but also to the fact that the presence of other Swifts is a powerful attractant to birds looking for a nest site.

The table below shows how many Swift pairs have been recorded nesting in boxes in Gordon Avenue, Milland Road, Nelson Road, Portal Road, St Catherine’s Road and Vale Road by year.

Number of Swifts Pairs Occupying Boxes in 2020-25 by Road

  As we found last year, the number of Swift pairs nesting in natural sites in Highcliffe in 2025 was very small. We recorded two pairs nesting in natural sites in Portal Road (both in gaps in dormer windows), one pair in a gap under a soffit in Milland Road, and one pair in a natural site in St Leonard’s Road (in a gap under an extractor pipe). In addition, we think that another two or three pairs who have previously been recorded as nesting in gaps high up in the gables at the rear of All Saints Primary School probably continued to do so this year. That makes an estimated total of seven pairs nesting in natural sites compared to 60 pairs in boxes. This is a huge change from what we found when we first surveyed Highcliffe as part of a Winchester-wide survey for nesting swifts in 2018. Just 7 years ago, we identified 17 pairs in natural sites and only 2 in boxes.

If anyone living in Highcliffe would like to help their local Swifts and House Sparrows by having a swift box installed on their house, please email us at info@hampshireswifts.co.uk.

We are very grateful to our long-standing Highcliffe surveyors, Rachel Hardy, Caroline Hill and Rachel Remnant for their help collecting data, and to new surveyors this year, Amanda Marshall and Chris Collins Lawn.

We also thank Winchester City Council for funding all the swift boxes fitted to their council housing stock.

Catharine Gale, Hampshire Swifts