Interesting Reed Warbler distribution

During their free time, a few BTO staff have been working hard, finding all the Reed Warbler nests on a large site near Mundford, Norfolk. This work also involves Constant Effort ringing and monitoring.

This encouraged us to think of where Reed Warblers are caught and originate from. Below is a map of Reed Warblers which were ringed in Britain and then recaught/found in 2010. You can clearly see the southward migration route and also the lack of birds in Northern Scotland.

The map is interactive so you can zoom in and out for more or less detail.

View Reed Warbler distribution in a full screen map

So where do birds from other countries, that are recaptured/found in Britain in 2010 come from? See below.

View Reed Warbler originating distribution in a full screen map

Recoveries in June

The processing of ringing recoveries in the demography team have been going very well recently. We've had lots of reports almost ready to send out to ringers and finders.

We thought it would be good idea to give you a taster of these (possibly unchecked).

Lesser Whitethroat Y60214 (blue pin) was ringed at Eilat Ringing Station, Israel on 10 March 2009 and was caught by ringers at Heysham Bird Observatory, Lancs on 12 June 2011 (1791km).

Starling LC14381 (red pin) was ringed on 29 Jan 2010 near Upton Magna, Shropshire was unfortunately killed by a cat in Minsk, Russia on 22 June 2011 (2022km).

A Redwing RT32238 (green pin) didn't do much better, after being ringed at Theddlethorpe St Helen, Lincolnshire on 15 October 2009 and hitting a window in Outokumpu, Finland on 4 June 2011 (1976km).

Sandwich Tern DK31758 (yellow pin) had its ring number read, probably while roosting. This bird was ringed at Sands of Forvie NNR, Newburgh on 30 May 2008 and was seen at Foce Isonzo, Staranzano, Italy on 5 June 2011 (1662km).


View June recoveries in a larger map

Other birds of note were a Hobby ringed in Powys seen at Minsmere, Suffolk (325km) and a Great Spotted Woodpecker found dead in a Squirrel trap.

Chough ringing in Wales celebrates 20th Birthday

Little did Tony Cross know when he first started colour ringing Welsh Choughs in 1991 that he would still be doing it 20 years later…

Between himself and project partner Adrienne Stratford, they have colour-ringed more than 4000 pulli as well as about 120 adult Chough, with over 20,000 resightings of colour-ringed individuals during that time.

A bucket of Chough by Kelvin Jones

“When we started the project, it was widely thought that the inland and coastal populations were completely separate, but we now know that they are part of the same population. It is apparent that they need good foraging habitats to be maintained in both coastal and inland mountain areas, as the same birds use both areas at different times of year and stages of their lives, with a lot of youngsters from all areas gathering into “youth-club” flocks in the mountains during their first and second autumns.”

Individual colour marking has allowed Tony and Adrienne to build an intricate picture of the birds’ social lives, breeding biology, movements and land use preferences. Currently, the oldest breeding Chough is 17 years old. In 2004, a flock of about 12 birds left Anglesey and went to the Isle of Man, three of these birds subsequently came back to the mainland, of which two are now part of the Anglesey breeding population.

During the intervening years, they have charted the fortunes of this iconic bird, its disappearance from most of inland mid-Wales, increases in some coastal areas, and recently, worrying signs of decline in inland Snowdonia, probably linked to reduction in grazing of upland pastures due to changes in agricultural subsidies.

Commuting Kingfisher

The great thing about running a Constant Effort Site (CES) is that every ringing session can be compared and analysed. One such CE Site is at Redgrave and Lopham Fen (Suffolk Wildlife Trust).

Catching on the morning of the 19 June was slow but the highlight for new trainee Sue Lawrence was a juvenile Kingfisher. Sue went to help at another CES that evening at Hinderclay Fen (Little Ouse Headwaters Project). Kingfishers are caught on most CE visits to Hinderclay Fen and one was caught that evening. Sue was pleased to see it again - it was the same juvenile she had seen earlier, 3km away!


The next session at Redgrave and Lopham Fen was run last Sunday (26 June) where they caught the same Kingfisher back at the original site. This shows just how much a juvenile Kingfisher moves up and down the river system looking for food. A brood of Kingfishers can eat over 100 fish a day, so this needs a lot of fishing.

Thanks to Dawn Balmer for the photo.

A Sedge Warbler Season

To understand our summer migrant birds, we really need to know their complete annual movements. With little ringing done in Africa, our Out of Africa appeal is really starting to 'bear fruit'. Our Norfolk Cuckoos are also looking like they are slowly moving south for the winter. Click here to see their current movements.

The demography team here at the BTO have recently processed reports of British ringed birds being caught at the National Park of Diawling in Mauritania. We have had very few Sedge Warbler recoveries from here but 100% of these have been by visiting ringers, mainly from the French Ringing Scheme. Two British ringed Sedge Warblers were caught in 2003, four in the winter of 2008/2009 and 17 for the winter of 2010/2011!

One Sedge Warbler, X396923 was ringed at Christchurch Harbour Ringing Station, Dorset on 9 Aug 2010. This bird was then caught 10 days later at Icklesham, Sussex (173km) after putting on a little weight. This same bird was then caught at the National Park of Diawling, Mauritania on 18 Dec 2010 (4035km)!


View Sedge Warbler X396923 in a larger map