Threats & Mitigation
Threats
Threats to nest sites may be temporary or permanent.
Temporary threats usually take the form of scaffolding or disturbance during the nesting season. While swifts can negotiate open scaffolding if it is constructed with them in mind, netting prevents all access.
Permanent threats range from the complete destruction of the building where they nested to minor repair work like repointing stonework or repairing loose tiles. Although complete destruction is usually non-negotiable, demolition can at least be timed to avoid loss of active nest sites. The swift species action plan requires that demolition should not take place between May and August where swifts are known to be or suspected to be nesting.
Other threats can be either designed out altogether or mitigated by replacing lost nest sites as close as possible to those lost.
The scale of the threat in any one instance varies depending on whether the buildings are in public, corporate or private ownership. Huge areas of redevelopment pose a greater single threat but are easier to identify and to mitigate by dealing with one or two key people. Piecemeal repair and development by individual house-owners offer a less serious immediate threat but may be harder to identify and mitigate unless the owner is sympathetic.
Mitigation
The success of mitigation measures depends largely on the ability to retain existing nest sites or to recreate nest sites in exactly the same position as those lost. Recreating nest sites even six inches away from the originals, fails to keep the swifts.
Here's a selection of common threats with mitigation measures:
Demolition
This 1940s tenement block in Gartloch Road Glasgow was demolished in late July.
As this was before the passing of the Nature Conservation (Scotland) Act 2004, we could not take action. Under the previous Wildlife and Countryside Act, “intention” to destroy would have had to have been proven. There was however a visit from the police to the company.
Mitigation?
It is possible to install swift nest sites on adjacent buildings and hope that the swifts find them. However, unless someone is prepared to play swift calls for at least one season this has not yet been known to work (around Glasgow at least).
Install swift nest sites in new buildings on the site. Of course there will be a time-lapse and to have any chance of swifts using them, it will be necessary to play calls, so unless it is either a publicly-owned building or a new resident is interested in helping out, this will not work.
An unsuccessful case
A successful case
( see also "some of the best")
Complete Renovation - building conversion (e.g. from older building to flats)
This can be a temporary threat if managed properly.
The biggest renovation threats are often carried out by Local Authority Housing or by Housing Associations and involve new roofs, fascias, windows, harling and rough casting.
During conversion, usually all pointing is renewed with enthusiasm, all old gaps in stone or brick-work filled, roofs are renewed and pipes replaced, leading to total and permanent loss of nest sites.
Conversion mitigation
With some forward planning, mitigation measures can be successful and exisiting nest sites retained.
Any building should have been thoroughly surveyed for bats and birds in any case. If not, ensure that this is done in the appropriate season (conversion projects do not happen urgently!). Swift nest sites can be noted, marked and retained within the conversion and, if possible, new ones created too!
Simple plywood nest boxes might be provided inside if internal works are likely to change the space inside the building.
See also Linlithgow distillery site.
Complete renovation, building conversion (e.g. from older buildings to flats, can be temporary if managed properly)
Kilpair Street in Haddington - where by accident or design, gaps in pointing were left under the eaves. We do not know if swifts still nest there however.
This style of tenement is typical of the peripheral estates of many Scottish cities, and I believe that we have lost hundreds of nest sites due to their renovation over the past 15 years, and the covering of the concrete lintel with PVC fascias. The irony of course is that the demolition of the old tenements which these buildings were built to replace probably destroyed even more swift nests – but we do not have records of that period.
Renovation - roof repair/replacement - Pantiles
Apart from disturbance during work pantiles are now normally blocked at the ends with a lump of mortar precisely to prevent birds and insects getting inside the spaces.
Mitigation
It is possible to leave at least some ends open. We have no examples of this being done intentionally.
Renovation - roof repair with flat tiles
Repairing broken roof tiles
A frequent cause of loss of swift nest sites, where swifts have been gaining access via broken or displaced tiles. This happened in Motherwell when some four-storey 1950s tenements were renovated.
Mitigation
Unfortunately there's no known measures as no one wants to leave broken or displaced tiles on a new roof. The Dutch tiles (above) incorporating swift nest sites are not yet available for purchase in the UK either.
Renovation, repair or replacing of ridge tiles
Swifts have been seen often nesting under ridge tiles where they were made of clay, and where gaps were sealed with mortar, which wore away over time.
A successful case
Renovation and repair of guttering and rone pipes
If gutters or rones are being replaced, there is no need to lose nest sites, as long as work is carried out outwith the nesting season. Simply ensure that the new ones are placed in the same positions as the old ones.
An unsuccessful case
On this site, in Barmulloch, where there had been probably six nest sites and where I thought we would keep the swifts as the concrete lintel was simply painted (2014), we lost them. I think it is because the new gutters are placed slightly lower down than the old ones and so restrict the spaces too much – as shown below. With forewarning and care and a good contractor, it would be possible to check the eaves before the new gutters were fixed and to mark and slightly carve out the concrete at the sites of existing nests.
UPDATE 2021: 3 nest sites were seen to be being used again and swifts were managing to get in under the new soffits.
Cladding soffits and gable ends
This is a common reason for loss of nest sites. During renovation, miles of the concrete soffits constructed in the 1930s to 1960s have been covered over with PVC fascias, eliminating the swift nest sites.
An unsuccessful case
This example shows the before and after of a gable end soffit that was clad in PVC during building re-roofing works. The original mortar pointing previously allowed swifts access beneath the tiles. Four nests were lost.
Re-roofing in itself need not threaten swift nest sites, if done outwith the nesting season, as long as the eaves are not altered. But where the fascia is clad with PVC, then the nest sites are inevitably lost.
This new PVC fascia in Barlanark covers the older concrete lintel at the eaves where swifts nested, and is a standard detail in renovation or re-roofing projects. This is common practice, and is possibly the single most common cause of loss of nest sites (in Glasgow at least), even though the PVC fascia is not essential, as pictures of other projects above show.
Window repairs
Generally this is not a problem as long as the scaffolding does not blocks nest sites and the nest access was originally in a gap at the window ledge.
Mitigation. Leave the nest site unless it has been the cause of water ingress.
Repointing
Repointing is a major factor in loss of nest sites in older and historic buildings. It is a grim thought to think how many swifts have been walled up in these repairs.
An unsuccessful case
Mitigation
Note and retain swift nest sites and create a few extra possible ones. There is no need to repoint the top course of stone-work too rigorously. It is usually protected from weather by an overhanging eave or gutter. A few gaps in the stonework do not interfere with the integrity or weather-proofing of the building.
Addition of an internal nest box may be preferred as here at Inchture church. See also Broughton House and Haddington, Kilpair Street.
An unsuccessful case
Renovation - minor works. New windows, rough casting, harling and painting
These works in themselves need not remove swift nest sites, so long as the entrances are not blocked off as part of the work or by new facing materials (but note also notes on scaffolding).
New buildings with special exclusion netting
Some people will go to great lengths to ensure that swifts do not get in to the building!
Mitigation
Install / create new nest sites or leave spaces for swift access.
Scaffolding
Scaffolding can be a temporary threat as it prevents swifts getting to their nest sites. There are examples of swifts deserting due their nests to (temporary) scaffolding, but also of swifts returning after being unable to get access for a season where the sites are retained.
Loft insulation
Filling the loft space with insulation can make it impossible for swifts to nest if the material is laid right up to the eaves. Insulation should leave about 200mm clear at the edges.
However, presence of the insulation may well deter swifts from using other sites in the building. Should we be placing plywood boxes at intervals along the wall-head to enable swifts to explore alternative nest sites in the future?
Retro-fitted external insulation
Climate change politics has hastened the application of external insulation panels to existing properties.
The application of external panels to eaves level blocks access to the swift’s original nest sites below the faschia.
Discussion is, at this time (November 2023), ongoing regarding recent projects in Dundonald and Kilmarnock managed by the Energy Agency on behalf of the Local Authorities. The Scottish Government provides substantial grant funding to enable mixed tenure External Wall Insulation projects. The council and housing associations fund work to their own housing stock and grant aid provides financial assistance to homeowners. A contribution is paid by other housing agencies or private owners. The level of contribution influences the rate of uptake.
