Thursday, 18 June 2020

Swavesey Memorial Hall

Swavesey Memorial Hall was built in 1919. It has a number of Swifts and House Sparrows breeding under open eaves. As part of the Over and Swavesey Swift Conservation project, we devised a way of adding more nest boxes on the gable.

The gable faces NW
The challenge is to do something that does not compromise the appearance of the building. The eaves of the gable are about 170mm wide and over 200mm deep, so there is plenty of space to hide some nest boxes out of sight.

4 double boxes
The design is a simple shoebox, installed sloping parallel to the eaves, but with a horizontal nest platform at the bottom of the slope. 4 double boxes were built, 2 for each side of the apex.

The slope is grooved to give the swifts some grip. The result is not unattractive and achieves the goal of preserving the appearance of the building.

The team was Bill Murrells, Bruce Martin and Dick Newell, with John Stimpson helping with minor adjustments.

8 nest chambers ready for Swifts or Sparrows

Design drawing

Wednesday, 10 June 2020

A neat renovation in France

Some time ago, we sent some half-brick entrance pieces to Carolyn Knowlman ( for a project in Amboise. Following this, an opportunity arose during a renovation, where some existing swift nest sites were under threat.

Offcuts used to make entrances
Rather than use entrance pieces cast out of concrete, the stone mason used offcuts to make his own entrance pieces.

The nest sites inside were preserved with a very acceptable end result on this beautiful house.

House Sparrows have already moved in to two of the entrances, but it is not known yet if the Swifts have returned to the 2 nest sites that they previously occupied.

Before and after the renovation

Close up of an entrance piece

Another close up

Spot the boxes

Tuesday, 2 June 2020

Eight S Bricks in 6 hours

Century House, Swavesey was reroofed 2 years ago. As a result a number of Swift nests were lost, and the roof was left in a state that Swifts could get into the roof space, resulting in some fatalities.

As part of the Over & Swavesey Swift Conservation Project, organised by Helen Pletts, it was decided to insert 8 S Bricks in the gable. It is a solid wall with no access inside, so everything had to be done from the outside. The bonding was somewhat irregular, so we had to make sure we chose stretchers to be removed which had a good chance of being aligned with the stretcher behind it. This was achieved by choosing stretchers adjacent to a header.

It was straightforward removing the outer stretcher, as the wall was constructed with soft lime mortar. In order to get hold of the inner stretcher, a handle was screwed into it to enable pulling it out. We had to be careful that nothing would fall onto the false ceiling inside.

Tailored S Bricks were made to fit this non-standard (Imperial) brick size. The backs of the boxes were coated in a layer of silvered insulation material to give some level of protection from heat from an uninsulated roof. For this project, the brick slips were  made by the Swavesey Sheddit group, a volunteer mental health workshop support project.

No other product on the market would have been practical in this situation.

The cherry picker was hired from Anglia High Access Ltd, who did a great job removing the bricks, with Bill Murrells, Action for Swifts, installing the S Bricks. From start to finish it took 6 hours

The project was funded by South Cambs District Council.

8 tailored S Bricks

8 bricks removed ready for 4 S Bricks

Bill Murrells fitting an S Brick

8 S Bricks installed

Overview shot

Sunday, 5 April 2020

Shepcot House Swifts

There is very little research on acceptable parameters for Swift nest boxes, so we have to rely on anecdotes. This is an example of Swifts nesting in a very small space indeed, perhaps giving a lower bound on what Swifts might find acceptable.

We are grateful to Catherine Day for talking about Shepcot House at the Bristol Swift Conference, Nov 2019 and to Mike Priaulx for the pictures and the information below.

Andy Potter - local Swift enthusiast

Shepcot House in Enfield is due for renovation, but it already housed a thriving colony of 27 pairs of Swifts. These birds have lost their nest sites, but 68 Ibstock Swift bricks in the new development have been provided, installed with the guidance of an ecologist (Middlemarch Environmental) during 2019
(see and search for 'shepcot')

The Swifts have been nesting in spaces 4cm high x 6.5cm deep x 26cm long behind the panels. They nested in the slots from the 2nd slot up in the picture on the left. The lowest slots with breeding Swifts are estimated at a little over 4 metres.

One of the slabs has fallen off allowing close inspection of the space behind, as in the pictures below.

Some of the panels have swifts nesting at both ends of the panel. Others are not used, and may have less space behind.

Most of the occupied panels face due south, so the panels must provide a degree of thermal insulation. The south elevation has the most open aspect and the unhindered flight line seems to be a factor.

There seemed to be no record of this Swift colony prior to it being highlighted during the construction works, so it is not known how soon these buildings were colonised after their construction during the 1960s.

There was a planning condition for nestboxes but the new provision by Countryside Properties has been voluntary, based on the ecologist's advice.

Here is a link by the developer:

[Also of relevance is this post about Swifts breeding in a House Martin's nest :]

The Swifts did not nest in this slot, as the front slab had fallen off
Slot height is a little over 4 cm
Slot depth is about 6.5 cm

Saturday, 4 April 2020

Face-plate Swift box

Swift boxes are normally thought of as 'external' or 'internal'.  John Crowther of Stroud wanted to retrofit swift bricks into his stone walls.

When John removed a stone, he found that there was no cavity and the space created was L 290mm x D 125mm x H 100mm. First thoughts of fitting an S Brick would have reduced the 125mm depth to about 100mm, which might have been enough space, but a 10cm depth for a bird with 175mm wing-length is a bit of a squeeze, though Swifts can nest in a space this small.

As we wanted to give the Swifts a little more space, and John preferred not to install another external box, we compromised by making 2 face-plates to close off two spaces. At the same time we added 12mm to the 125mm giving an internal depth of 137mm. Though not as unobtrusive as an internal Swift brick, it resulted in a neat solution.

To keep water out of the nest chamber, there is a layer of sealant between the face-plate and the wall

The material, 12mm MgO board, was left over from the stand we shared with Genesis Nest Boxes at Futurebuild - now a 4000-bed hospital.

The following pictures illustrate the concept:

2 face-plates showing outside and inside

One stone removed and face-plate installed

Wednesday, 12 February 2020

S Bricks in a rendered wall

This is the end result of the project reported here: 

S Bricks do not have enough headroom to house a camera, which is why 4 out of the 10 Swift bricks in this project are a custom design.

The 'before' picture: the hip roof in the middle is to be converted into a gable

S Bricks installed
4 custom camera boxes installed
The 'after' picture: 6 S Bricks and 4 custom camera boxes installed

Sunday, 9 February 2020

A solution looking for a problem

This is a bit of fun. We were presented with the problem of a building in Swavesey with Swifts nesting on top of the wall in a high gable. The Swifts are sometimes getting into the building, occasionally found dead.

The owners do not want to lose their much-loved Swifts. There is no way to get at the inside of the gable to block their entry. So the solution seems to be to provide alternative nest sites in the same gable, then block the entrances on the outside.

It is a solid wall, with headers and stretchers. So we came up with the idea of removing a header and then inserting a configurable nest box as described in this animation:

                  [Hit (ctrl) > loop to make it loop] 

The overall dimensions of the nest box, with the slider retracted is 30cm x 12cm x 8.3cm.
A simple box this size would give an internal floor area larger than an Ibstock Swift brick, but slightly smaller headroom. Although this would have been an option, we wanted to give the Swifts more space.

Having built a working prototype, we have now discovered that there is no insulation beneath the recently re-tiled roof, which means the roof space would get dangerously hot.

We are thus reverting to a plan B, which will probably be S Bricks with an insulated back embedded in the wall.

Saturday, 11 January 2020

Modified Schwegler 1MF

The Swifts Estate nest boxes in Fulbourn Cambs are one of the most successful projects in the UK: 276 nest boxes in 250 dwellings are home to 100 pairs of Swifts, together with House Sparrows, Great Tits, Starlings and House Martins.

The nest boxes comprise 168 custom made internal boxes and 54 Schwegler 1MF double boxes (108 nest chambers). However, 90% of the Swifts are in the internal boxes with only a handful in the Schwegler 1MF's. (See here for internal nest box design).

2 internal entrances near the top of the gable
and the modified Schwegler 1MF. The other side
of the gable is a mirror image (click to enlarge)
So we mulled the idea of modifying the entrances of the Schwegler 1MF's to be more like the internal boxes.

Andrew Tristram, who lives in another part of Fulbourn also had 2 Schwegler 1MF's on his gable, which attracted breeding Starlings. He reduced the entrance size and played Swift calls, but still no Swifts. We then installed 4 Cambridge System internal boxes inside the roof space, and 2 pairs of Swifts moved into them.

As an experiment we then made 2 new entrance plates for the 1MF's with horizontally facing entrances, with a similar appearance to the Cambridge System entrances.

Although it is too early to draw firm conclusions, 1 pair of Swifts moved into 1 of these modified boxes. We intend to replace more of the 1MF entrances, but we need to wait another season to get any more data, so we thought we would publish this now.

Saturday, 4 January 2020

The Swift Micro Caller

Graham Fell of Kendal Swifts has discovered some amazing new technology: an MP3 player costing less than £1. 

Together, and with others, we have been trialling it and so far we believe that it is a viable, very low cost solution. There are many vendors selling this piece of kit; try googling "TF card U disk MP3 Format decoder". It comes as a printed circuit board, there is no housing, you need to supply your own.
You can plug calls in on a USB memory stick to the U disk port, or on a Micro SD card into the TF card port. The tweeter should be connected to the 3W Speaker port. The system is powered with a Micro USB cable compatible with a mobile phone or Kindle charger (not iPhone).

Our analysis so far:
1. Volume is not quite as loud as Cheng Sheng/Kinter type systems at maximum volume, but it is loud enough for most situations. Usually one turns the volume down on these other systems.
2. Sound quality is good, with no distortion at maximum volume.
3. Control buttons not as convenient as control knobs, but not difficult to use.
4. There is only one speaker port (2 on a Cheng Sheng). We have not tried connecting 2 tweeters in parallel to this port.
5. We don't know yet what the Swifts might think of it.
6. It seems to consume a very low amperage, so we are testing to see whether it is feasible to run for a whole season on a single battery charge, without solar panel.

For a complete system, you need:

The TF card
USB memory stick or Micro SD card with calls in MP3 format
Micro USB cable (£1 from Pound shop)
USB mains plug (£1 from Pound shop)
Tweeter and speaker cable

You can probably buy all this for  less than £10
And you need a 240 volt timer.

As an interim we have made some housings on a laser cutter. as in the following pictures:

Micro Caller with Micro SD card
Micro Caller with USB memory stick
With power on and a USB memory stick or MIcroSD card inserted, the Micro caller will start to play, cycling indefinitely through all the tracks.
To increase volume: continuously depress the Next/V++ button
To decrease volume: continuously depress the Prev/V-- button
To move to the next track: short press on Next/V++ button
To move to the start of the current track: short press on Prev/V-- button
To stay on the current track: press Repeat
To revert to cycling through all tracks: power off and then power on again.

Saturday, 16 November 2019

Inspirational Swift boxes in Segovia

Thank you to Javier Saez Frayssinet for sending these pictures of the nicest installation of integral Swift boxes that we have seen. Hopefully this will demonstrate to architects just what is possible with a little imagination.

In Javier's own words:

This is a story about a renovation of the facade and interior of a building located on Juan Bravo Street, within the historic city centre of Segovia.

A colony of Swifts nests every year on this facade. Under each balcony there was a corbel and the Swifts took advantage of the gaps between them.

When the renovation began, I was on vacation. When I returned to Segovia I found that scaffolding and a protective net had been installed.

I watched as the swifts tried to enter their old nests but the netting prevented it.

I contacted the local authorities and the owner of the building, who decided to lower the netting to the 2nd floor. As this new arrangement was not enough I spoke with the owner again and the netting was lowered further to the 1st floor where the swifts were not nesting.

Because there was now a risk that rubble could fall on pedestrians the architect decided to stop the renovation until after the swifts had finished nesting.

The Swifts returned to their nests and successfully raised their chicks.

In order that in future years the swift colony would continue in the building, different alternatives were studied and it was decided to make nest places of plaster. The inside of each new corbel was divided into two parts with a plaster partition. The length of each nest chamber is 70cm, depth 17cm and height 15cm.

We think that it is a good solution for historic or modern buildings that have this kind of facade. The protection of a swift colony has been combined with the renovation of a historic building, resulting in a very pleasing solution.

Now we hope that when the swifts return at the end of April 2020, they will find the new homes we have built to be attractive.

The realization of this project was possible because the architect, Carlos Martin, enthusiastically received our proposal to make the nests. The construction manager, Vinut Calmorot, installed the corbels and made entrances, using the formers that Dick Newell had sent us (for this project). The interior division meant that under each balcony there are two nests available for swifts.

In addition to the 16 Swift boxes that you see here, another 5 have been installed on the roof.

16 Swift boxes

How neat is that!

Thursday, 17 October 2019

Dark versus light interior experiment

This post is more about trying to persuade people to do similar experiments than publishing a conclusive result.

A point of debate has been whether it is a good idea to paint the inside of a Swift box black or to leave it unpainted. Two years ago we erected a 10-box triangle (apex box) at Trumpington Meadows Nature Reserve and we painted half of the chambers black inside (see here).

When we recently inspected the boxes, we found evidence that Swifts had explored all 10 chambers, they had built nests in 5 boxes and had bred in 4 of them. With the boxes numbered from the top down and from left to right, the occupied boxes were 1, 5, 7, 9 and 10. They did not breed in 1. Of these 5, 4 are unpainted and only 1 is painted (10). [In addition a pair bred in the Starling box that you can also see in the above picture - this was unpainted inside, but is not included in the analysis below].

The probabilities of randomly distributing 5 pairs of Swifts in 10 nest boxes, half painted black would be:

B = black, W = unpainted
5B + 0W = 0.4%
4B + 1W = 9.9%
3B + 2W = 39.4%
2B + 3W = 39.4%
1B + 4W = 9.9%
0B + 5W = 0.4%

So the probability of 4 or more pairs occupying unpainted boxes is 10.3% (9.9% + 0.4%)
It needs to be less than 5% to be called "statistically significant"

We don't need many more experiments like this with a similar result to get a definitive answer.

Friday, 6 September 2019

Swift brick camera box

We were asked about cameras in Swift bricks installed to mitigate loss of nest sites under eaves in a hip to gable roof conversion.

Ten Swift bricks will be installed, 6 S Bricks high up in the new gable and 4 custom-built Swift bricks with cameras at the same level as the original eaves.

Most Swift bricks are too small to accommodate a camera, and are not constructed for easy access for maintenance.

The situation is a cavity wall 30cm thick, where access to the boxes is required from inside the building. The outside wall is rendered. We decided to make something to satisfy these requirements:
  1. A material that could take rendering
  2. White lights in the box requiring placing the sensor outside
  3. A box large enough so that the camera could see the whole stage, without Swifts wandering off stage
  4. Access from inside the house.
This idea may well be beyond most DIY enthusiasts, unless you have the right tools. In our case a water tile cutter and diamond hole saws. You also need to make some jigs to hold things in place.

We used:
  • 5mm cement fibre board (aka undercloak or soffit board) for 5 walls of the box.  This comes in strips 15 cm wide. The inside wall is plywood.
  • A cast half brick entrance piece to get the entrance clear of the rendering.
  • A 9mm (internal) plastic tube protruding beyond the rendering for the white light sensor.
  • Cameras and white lights were obtained from
We considered 2 glues to assemble the box: Gorilla Glue and Stixall Extreme Power Adhesive. Either could do the job:
  • Gorilla Glue is more expensive but is easier to apply and goes off in about 15 minutes
  • Stixall is cheaper, but takes longer to apply and longer to go off.
We used Gorilla Glue to assemble the box and Stixall for the half brick entrance.

This Swift brick will occupy the outside 18cm of the 30cm wall, leaving 12 cm for temporary insulation between the back of the box and the room inside.

It may also be worth reading what we did here.

Cast entrance piece, cement fibre-board and plywood body.
Note plastic tube bottom right containing the white light sensor.
Access door for simple inspection and maintenance. Removable back for more radical maintenance
Internal dimensions L 34cm W 15cm H 14cm.  The sloping platform is 14cm long at 45°.
The cabling is tucked away beneath the sloping platform. 
The camera has a 2.8mm lens.
The platform is not glued in, it is easily lifted out with the camera and lights
Inside view. The sloping platform keeps the birds on stage

Thursday, 5 September 2019

Peak Boxes

We thought it worth publicising a relative newcomer on the Swift nest box market. Lester Hartmann has brought the world of CNC machining to making high precision nest boxes. With a career in building custom furniture he is well qualified to do so.

At Action for Swifts we have focussed on generating ideas, trying them out with amateur carpentry, then describing them as case studies on this blog. We are rather pleased that this has influenced not a few Swift boxes now being offered commercially. Some of our ideas are borrowed, then developed from the Dutch website
The Dutch were always a little ahead of us.

It is good to see Peak Boxes taking this forward, developing and improving on what has gone before.

Peak Boxes products are of the highest quality and should make a very worthwhile contribution to the recovery of Swifts. You can see all the Swift boxes here:

Every effort is made towards being carbon neutral – the raw material is Duraply; plastic is not used in packaging and shipping is with DPD who claim to be carbon neutral.
3-tier apex box

Saturday, 3 August 2019

Crumlin Swift Tower, a history

For a while now, we have been cautious about encouraging people to put up a Swift tower, because they are relatively expensive and there are so few case studies demonstrating success. Our thoughts are summed up here. So we very much welcome this contribution from Brian Cahalane of his experience with a Swift tower in his garden and how he made it a success.

Paddy and Sean arrive with tower from Stonyford Engineering
In 2017, having designed the Stoneyford Swift Towers a few years previously, I decided to install a mini one in my back garden.

I wanted to find out for myself how useful they would be, and was it really as difficult to attract Swifts to nest in one as some people think. 
Camera  and speaker cable runs down the pole
then ducted underground to the garage

I did, I suppose, have the advantage of a large colony at my house as well as mains power close at hand.

I began playing calls in late April of that year and by the middle of May, single birds were going into some of the boxes. This was the pattern for the rest of the season. 

In 2018 I revamped the roof, the internals, and the entrances as I wanted the tower to look more aesthetically pleasing.

By the middle of May four pairs had taken up residence, two pairs were not in camera boxes so I couldn’t be sure of breeding until later on when I saw the parents going into the boxes with food. The other two pairs in the camera boxes were breeding, single birds were going into other boxes all season. 

In 2019 I installed extra cameras and 7 pairs have bred, all the other 5 boxes now have pairs and I wouldn’t be surprised if there were twelve pairs breeding next year, I didn’t play any calls this year, however I did for the previous two years, the calls had no affect on the breeders at my colony even though the tower is only 30 metres away. 

What have I learned?

Calls need to be played, ideally from 4.00 am to 9.00am and from 9.00pm to 11.00pm in
May, June and July.

Towers need to be monitored to ensure this. A timer is essential.

[Eds: As sunrise and sunset change with latitude and longitude, maybe the simplest way of describing Brian's timings in a location independent way is:
From dawn for 5 hours and for 2 hours until dusk
You can find the times of dawn and dusk from websites such as:
A reasonable compromise date for the whole season is 1st June ]

Top floor of 3 floors. The tower is 19" square, each nest chamber is L 12" x W 6" x H 6"
The central square holds cables for the tweeter and cameras

For protection of entrances, we used Marshall Tufflex half round gutter 114m from Amazon

Revamped tower
TV screen in the garage with MP3 player on the shelf
The single egg laid on 29th May resulted in a fledged chick on 29th July

Tuesday, 30 July 2019

Innovative use of a cavity liner

When one installs internal boxes, one should try to either make them unobtrusive or an attractive feature.

One of the first internal swift box projects we did in 2014 used a 30mm wide cavity liner which we cut into pieces and then reassembled into a half-brick entrance (see here).  Then in 2016 Barbara Wager installed internal boxes in a stone wall with a system of entrances cast in situ (see here).

Here, Barbara has combined these 2 ideas resulting in a practical solution that is simple, effective and attractive.

In her own words:

"The nest boxes were made by taking out facing stones, inserting the vent brick slices, mortaring in with tiles over the entrance and then vaselined formers were mortared in. Inside they are quite roomy and the walls mortared to prevent chicks wandering into the wall fabric – what a fate. Our builder agreed that the nests would not cause the house to fall down. The vent bricks made three slices each. They’ll be sheltered by the guttering. Each nest was provided with goose feathers, as ours are still moulting. We haven’t installed cameras nor do we expect to ever be able to get up there again. Over to the swifts. The speaker will be over a bedroom window so we should be able to reach it in case of failure."

Sunday, 21 July 2019

Cameras in Swift boxes

Many people insert a camera into their Swift boxes. Normally the only option is to place the camera somewhere between the entrance and the nest, so at no time can you see the whole "stage". Usually the camera is aimed at the nest, and you may be lucky to see some wing tips as the birds peer out of the entrance.

This post is the result of attempts to get better pictures with cameras in nest boxes, particularly in All Saint's Church Landbeach.  It is part of a project to generate interest and awareness of swifts in churches sponsored by British Birds Charitable Trust.

We do 3 things:
  • Modify the nest box so that either the nest is between the camera and the entrance (or so that the entrance is between the camera and the nest)
  • Include white lights
  • Choose an appropriate focal length for the lens.

Nest box modification
In Landbeach church in 2018, 8 boxes were occupied (increased to 11 pairs this year, 2019). We modified 4 of these by extending them with a housing to take a camera. We installed 2 cameras, which are easy to move from one modified box to another. The original boxes had internal dimensions W 200, D 200, H 150 and were positioned behind louvres in the belfry.  The camera housing simply hangs onto the back of the box.

Original nest box with camera housing extension.
White lights
We used analogue cameras from Green Feathers who also supplied the white lights. These cameras are not as high quality as WIFI or IP cameras, but they are certainly easier to deploy. The lights have a sensor so that they are switched on and off suddenly when the sun comes up and goes down. When the lights are off, the camera works in the infrared, producing the familiar ghostly images at night.

Any concerns that the Swifts would be disturbed by sudden changes in light levels were unjustified - they appear to take no notice (similarly, they take no notice of some very loud bell-ringing).

The lights not only enable one to see colour,  they greatly improve the quality of the imagery and they greatly reduce light through the entrance dazzling the camera.

Lens focal length
One needs to choose a focal length compatible with the desired field of view. Too long a focal length will restrict it and too short will mean that things of interest appear too small. We used a focal length of 2.8mm

Example results

Video-clip from 4th July

Video-clip from 20th July

Video-clip from 27th July

Video clip from 26th July - a late returning adult (infrared lighting)

The north side of the belfry with 4 camera boxes on top