30 June 2011

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.

28 June 2011

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.

23 June 2011

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

17 June 2011

Sand Martin Shenanigans

Richard du Feu is currently taking part in a Retrapping Adults for Survival (RAS) study on Sand Martins at Whittington, Lancashire. Little did he expect that one of the breeding males L334091, ringed at the site on 08/07/2010, would be later re-caught by ringers, whilst wintering in Africa, at Parc National du Djoudj, Senegal on 13/12/2010 (4363km in 158 days).

Amazingly he retrapped this same bird, on Tuesday night, at the original breeding site, just 15 metres from where he ringed it last year.

Richard also had two French ringed Sand Martins so far this year and two British controls with several birds moving up to 15km along the river lune. Higher than average numbers of adults have returned to many colonies this summer so the prospects for a productive breeding season are looking good.

Thanks to Richard for letting us know and to Jez Blackburn for the photo.

15 June 2011

19th Welsh Osprey ringed

Kelvin Jones writes:

BTO ringer Adrienne Stratford (below) ringed the 19th Osprey chick ever in Wales on Monday (11 June), at the Glaslyn Osprey Project at Porthmadog, Gwynedd.

Ospreys were discovered breeding in the Glaslyn Valley in 2004, but due to an unseasonal summer storm the nest collapsed and it was then confirmed that there had been two chicks in it. The adult pair returned to breed the following year and have bred successfully every year since.

Of the ringed chicks, one from 2006 has returned to the UK and has bred successfully in Dumfries for the past two years. This year a chick from 2008 has been seen in both the Glaslyn and Dovey valleys.

There was another successful pair in mid Wales in 2004, but unfortunately it was impossible to ring the single chick they produced, due to the inaccessable nesting site.

Thanks to Kelvin for the rather relaxed Osprey photo.

10 June 2011

Nightjars and Lightbugs

Nightjars are now returning to the Forestry Commission's Thetford Forest and are pairing up ready to start nesting. Thetford Forest Ringing Group members were out on Thursday night in order to catch these birds to understand more about their movements on migration and particularly in their wintering quarters, as surprising little is currently known about this species. A first catch of four birds was a marvellous start to this new BTO/Biotrack project, supported by Shoreham & District Ornithological Society.

Unlike the Cuckoo, previously reported, the Nightjar is too small to have a Satellite transmitter fitted. Geolocator tags are an excellent alternative but we have to catch the birds again next year to download the information on their movements. These tags, known as Lightbugs, collect data on day length and time, which is used to calculate the bird’s global position to within 100km, each day. These daily locations will help reveal migration routes and wintering locations within Africa.

Just when you thought a near perfect night couldn't get any better, one of the females was discovered to be already ringed, RP01170. She was originally caught on migration, 171km away at Icklesham, Sussex on 15 September 1999 and we had not seen her since she was caught in the forest in 2008.

RP01170 has now broken the previous British and Irish longevity record, which stood at 11 years and 10 days, by 257 days. Amazingly, Brian Cresswell who helped fit the Lightbug to RP01170, originally caught the previous oldest Nightjar, in Dorset, back in 1992! So, quite a privilege to have handled the two oldest Nightjars in Britain and Ireland.

Thanks to Brian Cresswell and Forestry Commission for their valuable help and to Kate Risely for the photo (Lee Barber on left and Brian Cresswell on right).

08 June 2011

Cutting edge Cuckoo information

The Cuckoo has been in the news recently, and rightly so, because this is a fascinating species. Cuckoos have been declining in the UK for a while now and things are getting very serious. Part of the problem is the severe lack of knowledge concerning its migration route once it leaves our shores and goes south to Africa. With only one British ringing recovery in Cameroon, there is so much to learn about its movements and population dynamics.

To help fillthis gap in our knowledge, BTO staff and volunteers have fitted state-of-the-art satellite transmitters on five male Cuckoos caught in East Anglia. Their movements can now be tracked very precisely and you can follow them by clicking here.

The movements are updated regularly. One Cuckoo, Clement, was ringed on the BTO reserve on 19th May and is currently in France! Another bird, Chris, has left Norfolk and is now near Battle in Sussex.

This is an amazing project and these five Cuckoos will lead the way in some cutting edge science. At the same time they'll be contributing to the conservation of their species.

02 June 2011

Wood Warbler at Wentwood

Jerry Lewis writes:

The larch plantations of Wentwood Forest, Gwent, hold good populations of Wood Warbler, and it looks like they are heading for a really good season this year. I have been studying them here since 2001 and this year the early arrivals didn't waste any time in getting on with nesting. My earliest first hatch dates have generally been between 20th and 29th May, and this year is at least 3 days earlier and I have already ringed 10 broods, three of these will have fledged by now. Clutch size is also high - during the past ten years I have only had three clutches of seven eggs (2 in 2009 and 1 in 2004) but this year I have already had four, and it certainly looks like the early spring and weather has benefited them.

Lee Barber adds:

We've only had 3 reports of Wood Warblers from 2009 to now, moving any distance and these were all seen by ringers alive or colour ring reports. One of these birds travelled from Macclesfield Forest, Cheshire to Coed Bwich-Glas, Powys (147km in 3 years, not including its annual trip to Africa).

Thanks to Jerry Lewis for letting us know about his great work and to John Bowers for the photo.