Friday 26 July 2013

Micklemere Nature Reserve Swift Tower

Swift towers are becoming more popular, even though, as a concept, it remains to be proved how effective they are. In order to keep costs down, the well proven design of a Barn Owl A-frame box was adapted to contain 11 nest-boxes, 7 entrances in the front and another 4 in the lower sides.

Final assembly of the tower on its pole
The Micklemere Swift tower is made of 15mm marine plywood, with an additional roof made of well-treated feather board. The double roof is designed to protect the nest-boxes from the weather, both rain and sun.

The box was mounted on a substantial 8 metre telegraph pole, 1.5 metres of which was in the ground.

Heavy lifting gear is used to lift the pole
Micklemere Nature Reserve is run by Suffolk Wildlife Trust which is one of a number of reserves managed by Will Cranstoun.

Will is blessed with a team of keen and competent volunteers who did a great job making the tower, and then helping to get it erected.

The trust already had a stock of suitable timber, as well as a spare telegraph pole, so this kept costs down.

The tower is up. Photo Judith Wakelam
Micklemere also has a number of generous donors and sponsors who provided funds, most of which was required for the sound system, which will need to be played in the coming years to attract Swifts into the boxes.

The sound system is based upon the Cheng Sheng player amplifier, 12 volt battery and solar panel charger. [described here and here].

It may be necessary to keep this going from May to July, through daylight hours, for a number of years to be sure of attracting Swifts into the tower.
This is a great example of a larger organisation, the Suffolk Wildlife Trust, getting behind the project, competent management on the ground, and a team of willing and able volunteers to make it happen.

Photo Judith Wakelam

Design model for Micklemere tower

Monday 22 July 2013

Temperature experiment

It is generally thought to be not a good idea to place Swift nest boxes in direct sunlight. But this experiment shows that acceptable temperatures can be maintained in the sun.

by Dick

With the recent hot weather, I thought it worth rerunning an experiment I did a few years ago by making a direct comparison of a John Stimpson Zeist box, made of 12mm plywood, with one modified with an additional roof. I replaced the original roof with a close fitting piece of ply, then I spaced the original roof off this by using 3 strips of ply. I didn't bevel the new roof, as it conveniently provided 2 small triangular ventilation holes. I then painted it white. Both boxes were placed side by side in the sun and 2 max-min thermometers were placed inside at the ends furthest from the entrances.

The boards on top of the boxes are intended to simulate the shading effect of narrow eaves.
A view end on, showing the additional roof and air gap.
And the result is that the additional white roof reduces the temperature by up to 5°C. On 3 different days, I recorded maximum temperatures of 31.8 vs 37.0°C, 36.8 vs 42.1°C and 34.6 vs 38.4°C.

Part of this effect is the white paint - it certainly feels a lot cooler than the unpainted wood, and part is the shading effect and the air gap between the 2 layers of plywood.

The additional roof not only defends the box from the sun, but also from the rain, which is important for a wooden box.

We actually described this idea some years ago here and here


Sunday 21 July 2013

The Worlington Swiftfest

When the Swift nest boxes in All Saints church tower, in the small Suffolk village of Worlington, were inspected in 2012, we were pleasantly surprised to find 7 occupied nest-boxes, up from 2 the previous year. So the idea was floated of having a Swift evening in 2013 for the people of Worlington to come and be informed about their Swifts. Cameras had been installed in 2 of the nest boxes before the Swifts returned in May, and both had chicks.

by Vida Newell

The date was set for 17th July, a date of peak Swift activity. Displays and exhibits were assembled in the church. Before people arrived, Bob Tonks and Simon Evans inspected the boxes to find 11 occupied, with 8 chicks in 5 of them (only 5 because Swifts do not normally breed in their first year of occupancy). And the single egg in the 2nd camera box had hatched the previous night.

Part of the exhibits, showing the Trumpington Orchard swift tower,stories about Swifts, nest boxes
and nest bricks and a Swift mobile (top right). Photo Judith Wakelam
Organisation, displays and publicity for the event, principally by Judith Wakelam and Don MacBean, together with refreshments provided by Ellen Clowes with help from other church members, attracted an unbelievable turn out. Suffolk Wildlife Trust did a great job publicising the event.

About 200 people turned up to see the exhibits, to watch the TV monitors, to hear Dick Newell say a few unscheduled, but well-received, words (twice because so many more people arrived after the first time) and to enjoy the Swift spectacle outside, which, on this night, was particularly stunning. The TV monitors were particularly entertaining when an adult returned to feed its chicks.

John Stimpson put on an impressive display of nest boxes for many species, from hedgehogs to Barn Owls, and he ended up selling his complete stock of Zeist Swift boxes.

Television monitors on 2 nests with chicks and a map of the track taken by a Swift from Landbeach
that carried a geolocator to Africa and back. Photo Judith Wakelam
Worlington church proved to be a wonderful location for an event like this. The tower is not high, so to see 20 to 30 Swifts charging around, no more than a few metres above our heads, was particularly enthralling. The format and environment was an ideal way to get the message across to people about Swifts, their problems and what can be done about them.

People came from places much further afield than Worlington, from all the neighbouring counties as well as from Ireland. There were representatives from the RSPB, BTO and the Suffolk Wildlife Trust, all actively working for Swifts, as well as a number of people from AfS. Chris Hewson of the BTO was on hand to describe the results of geolocators on Swifts, unravelling the details of their travels through Africa.

Early on in the proceedings, one or two people asked "Why Swifts?". By the end of the evening, they had their answer.

Saturday 20 July 2013

How green is the green Deal?

An excellent article entitled “Swifts and the Green Deal” by journalist Cath Harris appeared in a recent issue of the magazine Bird Watching. Cath outlines the problems thrown up by the “Green Deal”, the latest government policy statement on action to reduce carbon emissions by insulating and sealing buildings where Swifts have their nesting cavities.

by Jake

Schwegler nest boxes installed to mitigate loss of nest sites elsewhere
Photo Devon Wildlife Trust
She goes on to highlight some of the nestboxing projects that have successfully mitigated the effects of current building regulations and practices. Among the success stories she quotes are the Worlington church initiative in Suffolk, as well as a number of schemes under the aegis of Edward Mayer's Swift-Conservation; and examples of local authority and county Wildlife Trust projects to help Swifts, such as the Fulbourn project in Cambridgeshire and the initiative in Exeter, where the City Council intends to install built-in Swift boxes in all suitable residential units. Cath Harris's article makes for heartening reading. You can find it HERE.

Sunday 7 July 2013

Swift's nest in a cramped roof space

The subject of the space required by Swifts to nest successfully is an interesting and relevant topic. Here is another example indicating just how cramped a space they will tolerate. When Tanya & Edmund Hoare,  in Lowgill, near Sedbergh, Cumbria removed the tiles from their property, they found that the space beneath had been filled with rubble, giving a very irregular steep surface.

Spaces between the roof joists filled with rubble
Nevertheless, Swifts had found their way in to a suitable concave depression in the rubble on which to build their nest. The roof joists are thought to be 3 by 2's (roughly 75mm x 50mm). On top of these would be battens ~25mm thick to support the roof tiles. Thus the average distance between the rubble and the tiles looks quite small, maybe 75mm, though doubtless there is a route through the rubble with more headroom and above the nest site itself. There seems to be no large horizontal floor area. The pictures below show the story.

A Swift nest built on a depression in the rubble
Clearing out the rubble reveals an normous potential space for nesting Swifts
After removing the rubble, the builders then built Swift nests in the spaces vacated.
On top of this Tanya & Edmund also installed Schwegler Swift bricks in the gable end of her property.

Schwegler Swift bricks installed in the gable end