Thursday, 14 August 2014

Cambridge Swift Tower - 2014 update

The breaking news is that, in the 4th summer of playing attraction calls, the Swifts have finally found the nest-boxes.

The tower was built in 2011 and we started playing calls with a customised bird scarer. Swifts showed some interest, but none were seen going very close to the nest-boxes.

We continued in 2012 with the same result and the bird scarer had become unreliable. We suspect the 5 watt solar panel was not quite up to the task, so we installed our own 'Box of Swifts' with a 1.5 inch car tweeter. The result was the same.

So, in 2013, after we had stumbled across the Cheng Sheng player amplifier, we installed a 20 watt solar panel to charge the battery which drove the player-amp and 2 tweeters. This resulted in Swifts actually making contact with the tower, clinging to the boxes, but still not finding any entrances. As a result of this, we made some more entrances where we thought the birds were trying to get in.

Solar panel facing south at 30°
In 2014, things seemed much the same, with Swifts regularly seen near the tower, but none making an entrance. At one point the battery went flat, so we resited the solar panel so that it was never in the shade and pointing in the optimal direction (south sloping 30°).

We seemed to be making little progress, so, in mid June, I popped an email to Brian Cahalane, an attraction call playing afficionado, to ask what would he do? His reply was to start playing calls at dawn and finish at dusk.

So the timer was reset to go from 5am to 12 noon and from 5pm to 10pm - this gave 12 hours of playing, we are not confident how much longer the solar panel and battery could go in a day. We had not previously played at the ends of the day for fear of disturbing local residents.

On 26th June, Bob Tonks was cycling past the tower, and he saw a Swift exiting one of the boxes (so thank you Brian and Bob). Since then we have seen Swifts entering or leaving 15 different boxes, 12 on the front and 3 on the back. Most observation has been done on the front. We saw no Swifts entering the new entrances that we had made on the back.

The only entrance in the top half of the back;
visited by swifts in 2014
We don't think there are 15 potential pairs for next year, as this was probably a small number of birds exploring their options.

One or 2 observations:

Although there are entrances at all levels on the front of the tower, Swifts only entered boxes in the top half. On the back, there is only 1 entrance in the top half, and Swifts used it. So, should we add more entrances in the top half on the back?

3 entrances with white canopies
were visited by swifts in 2014
Another thing, on the front, the paint had peeled away from the canopies above 3 entrances, turning them white. Swifts were seen entering these 3 boxes. The statistical probability of randomly choosing 3 specific boxes turns out to be about 2% - so should we paint a few more canopies white, especially in the lower half?

For the whole of July, if one loitered near the tower one would see anything between 3 and 10 Swifts in the near vicinity with some impressive screaming displays past the face of the tower. If this is a taste of what is to come, then it should be an impressive spectacle on summer evenings in the future.

6 comments:

  1. Another, possibly irrelevant, observation is that the topmost of the 3 boxes from which the paint has come off was used by starlings in 2013, as seen here http://actionforswifts.blogspot.co.uk/2013/05/first-occupant-of-cambridge-swift-tower.html On my own site at http://www.viridis.net/animals/starling-swift-tower.html you can see it's the same box (before the paint came off), and the starling-droppings below are visible in the recent photos.

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    1. Good point Clarke, though Starlings only occupied one of the boxes with a white canopy, but this could be a factor.

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  2. Excellent news about the Swifts finding their way to this magnificent tower Dick! I look forward to hearing what happens next season!
    On another note, I would be reluctant to change too much about the tower this quickly after the birds have shown interest (e.g. adding front entrances in boxes at the back side or adding white paint on the front boxes). These first birds have not even properly settled yet and who knows others attracted by a first nesting pair might well favor a box in the back with a bottom entrance.

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  3. Thanks for your comments Jochem, the thing is, there will be a cherry picker available in October, which will easily get us 11 metres high. So my feeling is to take the opportunity, because we do not know when we will get another one. We can make a small number of the suggested modifications. Say 3 extra holes high in the back and 3 more white canopies in the bottom half of the front.

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  4. Congrats on attracting Swifts! A great project. Regarding the seeming attraction of the white canopies, when I first installed my boxes in County Sligo, Ireland, with a call playing, the swifts found the boxes quickly but could not seem to find the entrances. On the advice of the same Brian Cahalane, I dabbed some correction fluid (Tippex) "droppings" below the entrances, and the effect was really dramatic, with birds tentering the first box that day, and entering several boxes within days.

    Could a similar effect be in play in your tower with the whiter canopies?

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  5. I loved your report. English is my 2nd language and I was surprised to discover that 'swift' is a bird :) It's certainly a sign for me :) Thanks!

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