Thursday 11 August 2016

Edgecombe Flats

In 2010, Cambridge City Council, helped by AfS,  installed 71 nest boxes on their properties at Edgecombe flats. In that first year, one of the residents, Peter Glass, played attraction calls from his balcony, resulting in 2 occupied boxes in 2010. Since then, 2 or 3 of the 4 boxes above the front of Peter's flat have been occupied by Swifts, but, as far as we know, none in the other 67 boxes on the site, until this year, 2016.

We have not said much about Edgecombe flats in previous years, because progress has been slow. The 71 boxes include 50 Zeist boxes made by John Stimpson, 5 boxes made out of water pipes and four 4-box cabinets.

A chick looking out of one of the boxes above
Peter Glass's flat, 2016.
This box is south-facing but has a double roof painted white
Having established occupancy in Peter Glass's boxes, in 2013 we installed a solar panel driven attraction call system with a tweeter in one of the 4-box cabinets, but this did not give a result.

The boxes above Peter Glass's flat were the only ones with major exposure to the sun, so they were given a double roof, painted white. This was an early prototype of the Model 30 now also made by John Stimpson.

In early 2016 we gave 2 of the boxes on the other side of the building a white roof, in the hope that the Swifts might recognise them. These boxes were also the closest boxes to the attraction system.

The result was that these 2 boxes were occupied, whether because of the white roofs or proximity of the attraction calls we cannot say.

In July, Chris De Ruyck of the RSPB was looking for suitable places to study Swift nest boxing projects, and so he spent some time at Edgecombe flats, resulting in him finding a total of 12 boxes occupied by Swifts, and many more with evidence of House Sparrows.

Some of the boxes occupied by Swifts also show evidence of previous occupancy by the sparrows, showing that Swifts are quite capable of nesting on top of a House Sparrow haystack.

Status map with thanks to Chris de Ruyck, RSPB
It is unlikely that there was a sudden increase in 2016, more likely we had not spent enough time monitoring in previous years.

Suffice to say, we are now optimistic that Edgecombe flats will grow into a major colony of both Swifts and House Sparrows. The success of this project should encourage other councils to do similar things. Projects like Fulbourn and Edgecombe show that it is all worth while.

The plan now is to inspect all of the boxes and do some maintenance, such as further wood treatment and reduce or possibly remove some of the House Sparrow nesting material.

The 4 boxes above Peter Glass's flat. These are Zeist boxes with an additional roof painted white.
3 of these boxes were occupied by Swifts in 2016
5 pipe boxes. These have been occupied by House Sparrows, and in one box the entrance
 has been completely blocked with sparrow nesting material. Swifts have not yet found these boxes.
There are 4 Zeist boxes in view on this aspect.
12 Zeist boxes are occupied by Swifts on the whole site.
One of 2 pairs of 4-box cabinets on the site.
There are House Sparrows nesting in these boxes, but no Swifts yet.

[Update July 2020: a careful, but quick survey looking for droppings below nest box entrances, chicks looking out and adults in or out yielded 34 boxes occupied by Swifts. Some boxes with chicks looking out had no droppings, and some boxes almost certainly contained non-breeders, so 34 is almost certainly an underestimate. Further, 32 boxes had evidence of previous occupation by House Sparrows in the form of grass or feathers in the entrance. 16 of these boxes had evidence of Swifts. There is a summary map here]
[Update July 2021: A minimum of 44 nest boxes with swifts were found, and 24 more nest boxes were added, bringing the total to 95]

#temperature #swiftpic

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