Sunday 25 August 2013

Swift Bricks

Written by Dick

Accommodation for Swifts built in to buildings is to be preferred to accommodation retrofitted on the outside. Planning departments  are now conditioning new developments and renovations to provide space for wildlife in the interests of biodiversity: bats, House Sparrows, Starlings and Swifts.  We have produced a downloadable pdf with all of the Swift bricks that we have found so far, with pictures, a table of dimensions and approximate prices. This has now been taken on by the RSPB and Swift-Conservation as a good way to promote Swift Bricks.

Here are a few examples to whet your appetite:

This is a box designed so that the replaceable front can be matched with any existing brickwork. We reviewed it here

CJ Wildlife Woodstone 
This is one of 3 models that CJ Woodstone supply, the others you can see on their website. The one illustrated here is the 90068.

The front can be custom made to match any bricks. There is another version with the entrance 1 brick lower.

An attractive brick, designed to encroach minimally on the cavity. We have an account of an early success here.

Perhaps the oldest established company in the Swift brick business. There are a number of designs in their catalogue, including the Cavity Panel. Schwegler boxes have been very successful for Swifts.
The one illustrated here is the 16S.

Hanson clay air brick liner 
The model 401 makes an attractive, low cost Swift brick. We wrote up how to make and install it here, and Swifts seem to like it.
(Scroll to page 9 on the PDF)

Monday 19 August 2013

BTO Breeding Bird Survey Report 2012

The BTO/JNCC/RSPB BBS report for 2012 is now published; you can download and read it here

by Dick

It is a good read representing the results from 3,430 randomly allocated 1km squares. Each square is surveyed twice, the early surveys, in April to mid May, are likely to record fewer Swifts than the later ones in mid May to late June when the Swift population is at its peak.

Unlike song birds, Swifts recorded in a 1km square, out in the country, are unlikely to be breeding in that square. Indeed, they are almost as likely to be non-breeders as breeders, but one hopes that the frequency of occurrence of Swifts during BBS surveys is a good proxy for the general population level. For Swifts it is more a total population level index than a breeding bird index.
BBS Index for Swift, UK, 1994 - 2012
Index values are scaled so that the smoothed index in 1995 is 100
The results presented for Swift for the whole UK record a decline of 39% between 1995 and 2011, then an increase of 20% between 2011 and 2012.

So the 2011 UK population is estimated at 61% of the 1995 population. Note that this is calculated from the values behind the smoothed red trend line. The years 1994 and 2012 are not used as the smoothed values at the extremes are not considered reliable. Thus we have scaled the graphs so the smoothed index value in 1995 is set to 100.

Although the 2012 annual index is 120% of the 2011 one, it would not be appropriate to multiply the 2011 smoothed value by 120%, as the 120% figure comes from the annual index values

See BBS 2012 report for confidence limits
The numbers are also presented for 3 of the 4 UK countries, there was not enough data for Northern Ireland.

However, all of the numbers in this table have wide confidence limits, so we will have to wait for 2013 and beyond for smoothed index values in 2012.

It is tempting to speculate that the long wet summer of 2012 forced Swifts out into the countryside to feed in areas where there were BBS survey squares. However, this does not explain the situation in Scotland.

Thank you Kate Risely, BBS National Organiser, for providing the data for the graphs.

Saturday 17 August 2013

Nest Recording of Swifts in Boxes with Cameras

The increasing number of people with cameras in Swift nest boxes provides a great opportunity to obtain high quality nest records for the BTO. This could help to reverse the decline in numbers of Nest Record Cards for Swift in recent years

Written by Jake & Dick

The BTO's Nest Record Scheme provides important information about changes in populations over time, based on such factors as average egg laying date, clutch size, incubation and fledging period, and hatching and fledging success rates.

Nest record cards for Swift recorded each year
showing the recent decline (click graph to enlarge)
3 chicks with large primary feathers
(can you spot the 3rd one?)
We know there is an ongoing decline in the population of Swifts in this country, so it is important to collect data on breeding success rates, but no more than a hundred nest records are received each year, and this number has halved since 2010.

Historic data would be extremely valuable in helping to combat the dearth of records in recent years.

Moreover, the information on the cards is generally minimal, possibly no more than the record from a single visit.

Even with multiple visits, The BTO has to make intelligent inferences to determine egg laying, hatching and fledging dates. With cameras in boxes, there is the potential to determine the timing precisely of all of these events without any guesswork.

Example nest record card
Nest recording is not an arduous task, though the more you record, the better. The optimum would be to produce a series of up to 10 dated observations detailing the first sighting of an egg in the nest, the maximum clutch size and when it was first observed, the date of first hatching, the number of chicks present at approximately weekly intervals, together with their stage of development, and the timing of any failures or successful fledging.

In the (real) example shown here, we knew everything from the date the parents arrived, when the eggs were laid, when the eggs hatched, when the chicks fledged, and finally when the parent left for Africa. In this case, one parent went missing on 4th July. [The parent that survived carried a geolocator to Africa in 2011 and has returned since then.]

Note that although the instructions say that further visits should be included on continuation cards, the BTO nest record software cannot deal with more than 10 visits, meaning that all of the most essential information should be squeezed onto the first card.

In this example, we have inserted the last time there were 2 eggs, just before there was 1 chick This helps the BTO's algorithms to pin down the hatching date exactly. Because of the 10 visit restriction, we have not recorded the dates that the parents arrived on the card.

If you know that you will be unable to watch the camera for a period, record the last state of play, including nest contents, primary feather length etc. as well as the position on your return. See this pdf link, also referenced below, for how to describe chicks.

Anyone who would like to contribute can get in touch with the BTO at to register as a nest recorder and receive the necessary instructions and blank cards. It is essential that the data is submitted on these cards, as the BTO cannot handle any other format.
[ we understand that there will eventually be a web-based system]

If you already have such information recorded from previous seasons, it is an easy matter to transfer it to Nest Record Cards using the standard BTO codings.

For a fuller description of how to record Swift nest records download this pdf, written by Vince Lea.

We thank Dave Leech, BTO Senior Research Ecologist NRS, CES & RAS, for suggested improvements to this post.

BTO url:

Thursday 1 August 2013

South Cambs District Council - nest box initiative

South Cambs District Council, under the leadership of ecology officer Rob Mungovan, is particularly active in providing nest-boxes for Swifts.

This is best exemplified by their highly successful deployment of 250 Swift boxes on the Swifts estate in Fulbourn.

Now, seeing the threat to cavity nesting wildlife from government sponsored insulation schemes, they have a new initiative.

Click on either image and read for yourself.
Or you can download a pdf here