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.