Concerns for Swifts - follow link

Facts about swifts

Swifts are beautiful and amazing birds.  They are black, with long swept-back wings in the shape of a sickle or scythe.  Although they look superficially like house martins and swallows, they are not related to either species.  Swifts are aerial masters and can fly up to an altitude of 6,000 metres.  They feed and drink (water droplets in clouds), sleep, and even mate on the wing, only landing to breed. 

Swifts come to Britain during the summer, arriving in May and departing during August to spend the winter in Africa.  Whilst here, they breed.  Traditionally, this would have been in caves, on cliffs, even in tree cavities.  However, these nesting sites are rare, so swifts have taken to nesting in buildings.  During the summer months, swifts can be seen flying above many of our towns and villages, particularly when they form what are know as ‘screaming parties’ where groups of birds chase each other at high speed.  The sight and sound of these parties is a quintessential element of our summers.  But, swifts are under threat!

Swifts, nest in colonies predominantly in pre-1944 buildings, church spires and towers.  They can nest in eaves, in holes around pipes, behind worn and missing masonry, and under loose or missing roof tiles.  All these sites are at least 5 metres from the ground with a clear flight path for the birds to fly directly to the entrance.  Access to the nest is usually small; typically 35mm deep and 65mm wide.  In houses, nests are usually situated just inside the outer wall, behind the soffit board; rarely in the main loft space.  Swift nests are clean, using very little material, which is glued together by the bird’s saliva.

The threats to swifts

Modern architecture, building regulations and techniques deny swifts access to potential breeding sites.  The demolition and renovation, particularly the re-roofing, of old buildings, also denies them nesting sites.  Worse still, most roofing work takes place during the summer, destroying nests and young, despite the fact that they are protected by law (Wildlife and Countryside Act 1981 as amended).   As a consequence, it is estimated that the British population of swifts has declined by 60%.

Why should we care

The government has identified the diversity of our bird life as one of its Quality of Life Indicators.

Local authorities have a responsibility to maintain and enhance the biodiversity of their areas.  Therefore, planners, architects and builders have a special responsibility to protect the natural world.  Swifts are a vulnerable urban species that can benefit from considerate development works.  Minor low-cost initiatives in building design will ensure that swifts have a future in our towns and villages.

How to help swifts

Normal Building Regulations, Planning Laws and Listed Building Consents will need to be satisfied.

Roofing and soffit board work:

Not all buildings will have swifts.  However, for those that do, it would be illegal to intentionally damage or destroy the nests of swifts whilst they are in use.  It is essential therefore, that roofing and soffit work is not carried out during the period between 1st May to the end of August; a period of just 17 weeks or one-third of the total year.

Providing new nest sites:

Nesting sites must never be situated in strong sunlight.  Therefore, ideal locations for nest sites are on the north, north-east and north-west sides of buildings.


  • Plywood nest boxes, made from WBP 12mm plywood, can be fixed externally under the eaves. This is a cheap alternative when an internal solution is not possible. The boxes can also be fitted just inside the eaves, with a suitable entry hole accessible from beneath.
  • Internal ventilated plywood partitions (30-40cm) can be installed inside the eaves, with an open ventilation gap.
  • Swift ‘nest bricks’ (woodcrete) can be installed in the fabric/brickwork of a building (see Useful Information below).

 Offices, apartments, factories, warehouses and utility buildings

 Swift ‘nest bricks’ (woodcrete) can be installed in the fabric/brickwork of a building.

  • Two-storey surface-mounted woodcrete nest boxes can be fitted to an outer wall at roof-level on plant rooms and air conditioning units.
  • Nest sites can be built into ventilation turrets with swifts gaining access through the louvres.
  • Church towers and spires offer swifts (and bats and owls) safe nesting sites. This can be achieved by allowing access through existing ventilation slits, louvres and hoods to self-contained nesting areas kept separate from the rest of the interior.

Useful Information:

Nest bricks for buildings; model N25.  Order code A02044

Swift box (mimics bell tower louvres) No. 16 (single or double), plus nest mould

Swift box No. 18 suitable for fixing under eaves.  Order code A02041A

available from:

Alana Ecology Ltd, The Old Primary School, Church Street, Bishop’s Castle, Shropshire.  SY9 5AE.  Tel: 01588 630173. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.


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