Swifts, Apus apus, and How to Help Them.

by Judith John.

Swifts arrive in the UK in late April or May to breed, usually at traditional nest sites, and leave in July or August for South Africa. Whilst in Britain their chief requirements are food for themselves and developing young and safe breeding sites. Swifts feed on flying insects and spiderlings high up on air currents, bringing from 300 to 1000 insects in each bolus of food they bring back for their chicks. The number of swifts arriving in the UK declined by 47% between 1995-2014 and more recent RSPB figures show a 51% decrease in their breeding numbers between 1995 and 2015.

In Bromley numbers recorded are now very low. The pilot study carried out this year returned only three definite records of breeding, in Mottingham, the Hillcrest Road area of Orpington and in the Petts Wood area. They have been seen flying at rooftop level near Orpington Station, which suggests they may have bred close by, but this needs further investigation. Swifts are also known to have bred in the Bromley South area in the past, but their numbers here have declined over the last 15 years from 12 in 2002 to 2 in 2014, and none have been seen since then in this area.

Records were also received of swifts flying above the Goddington Park area, Oakhill Road near Orpington Station, Friar Road & Robin Hood Green Poverest, Downe and High Elms, Leaves Green, Pickhurst Rise West Wickham and Hayes Road Bromley.

The swift survey will be repeated in 2018 with posters going out in April (earlier than in 2017). Bromley Biodiversity Partnership will be working closely with Bromley RSPB who are also carrying out a swift survey this year. We will both be asking for records of swifts flying at rooftop level or any evidence of breeding, with some RSPB members visiting allocated squares a minimum of once in May, June & July to record the location & number of swifts flying at rooftop level or entering a possible nesting site. If you would like to join the RSPB swift survey and be given an allocated square, please get in touch with Bromley RSPB by e-mailing bromleyrspb@gmail.com .

Meanwhile, although there may be many reasons why swift numbers have been dropping which we cannot influence because they live overseas for much of the year, there are 2 problems which it may be possible to address in Bromley borough: reduced nesting sites and reduced availability of insect prey.

Loss of nesting sites

Swifts generally nest within holes and cavities in the roofs of older buildings in larger villages, towns and cities. With the increased drive for better insulation, buildings are better sealed than in the past, so swifts are returning to discover their nest site has gone or access is blocked. This situation could be remedied by the installation of swift bricks in new buildings or when houses are re-roofed or renovated so, especially in areas where swifts have been seen, when planning application is applied for new builds or renovations it is worth asking for swift bricks to be incorporated as a condition of permission being granted.

They can also be put up by individuals. Swift bricks cost from £15 and are readily available on the internet. Ideally at least 2 should be put in since swifts tend to nest colonially and it is a good idea to purchase a CD of swift calls to attract them - these cost about £2. There is lots of advice about where and how to site them at www.swift-conservation.org. Swift boxes can also be bought or made but these do not last as long.

Loss of Insect Prey

It has been known for some time that insect numbers in Britain have been falling: most people have noticed how few insects are found on car windscreens after a long journey. A recent study carried out in Germany and reported in the Guardian showed a 76% decline in numbers trapped by the same method in nature reserves over a 27 year period.

Planting more native species in gardens and encouraging the local authority, schools and sports grounds to plant hedgerows of native species and leave areas of grass uncut during the summer would help to increase prey items as native invertebrates in the UK are adapted to live on native species, so far more are found on these than on exotic plants. Decreasing pesticide and herbicide use and encouraging others to do the same would also help.


To see or download a poster about helping swifts, please click here:

     Downloadable Swifts Poster

RSPB Swift Survey, May-July 2018

If you would like to take part in the RSPB's swift survey this spring, please click here:

     Downloadable RSPB Swift Survey poster

This article is copyright © Judith John 2018.