August recoveries update

"I found a bird's leg in my sock!"

Over the years there have been some odd finding places for bird rings, including at the bottom of the North Sea, a Red Kite in the engine of a plane and a Mute Swan killed by a Lion at Chester Zoo. This month's winner is quoted, "I put my sock on this morning and felt something sharp dig into my foot. Upon further inspection, and to my disbelief, I found a tiny metal ring attached to a dismembered birds leg!". We are waiting for the ringing details on this one, but the leg was small, perhaps Wren or Goldcrest sized.

With the start of the shooting season, reports of ringed wildfowl are increasing. Last month we had 2 interesting reports of Pochard that were shot in Samarskaya Oblast, Russia (3287km) and Shaturskiy Rayon (2600km), Russia, after being ringed at Welney WWT, Norfolk in 2007 and 2008 (yellow pins).

Passerines played their part last month with Common Redpoll L656176 (blue pin) being ringed by Spurn Bird Observatory on the 16th of October 2010 to be then controlled by a ringer in Finnvik, Tromso, Norway on 5th August 2011 (2035km in 293 days).

View August update in a larger map

We don't normally get many reports of dogs attacking birds (apart from the odd swan) but House Sparrow TS36895 was very unlucky to be killed by a Jack Russell while flying past a bird table! Cats are the normal cause of death in gardens, partly because they frequently bring the ringed bird to the owner for reporting. Out of the 32 'caused by predator' reports during August, 22 of these were from cats, with the next highest being five deaths from birds of prey.

CES ringers finally get a lie-in

Greg Conway writes:

As the breeding season draws to a close, so the hundreds of dedicated ringers who run the 120 Constant Effort Sites (CES) scattered across Britain and Ireland can start to relax and recuperate after a summer of early morning starts. As they use the same mist nets in the same places each year to catch the birds, the information they collect tells us about changes in numbers of adults and juveniles over time, so abundance, breeding success and survival can all be measured, making this one of the most valuable ringing projects.

Target species include many of our long-distance migrants (e.g. Reed Warbler, Sedge Warbler, Garden Warbler, Whitethroat, Willow Warbler) plus resident scrub species such as Wren, Dunnock, Blackbird and Robin.

The CES scheme started in 1983, so ringers have just completed the 29th season and will soon be focussing their attention on getting all their data to BTO HQ ready for analysis. The results of the most recent CES analysis can be found on the species pages here and the preliminary results from 2011 will be available later in the autumn. These will provide the first indications of abundance and breeding success of birds nesting this summer, helping to assess the potential impact of yet another harsh winter.

Early indications suggest that a number of migrant species have returned in greater than usual numbers. However, despite an early start to the breeding for many species, prolonged periods of cool and wet weather, particularly in the north and west of Britain and Ireland, were associated reduced breeding productivity levels.

A big thank you to everyone whole has help with CES this year and those ringers who have already submitted their data.

Thanks to Dorian Moss for the above picture of Lucy Yates and Kate Risely for the top picture of Nick Moran.

Waiting for the kids to leave home

Over 36,000 Reed Warblers were ringed in the UK during 2010, so what was interesting about the seven caught at a site in south Norfolk on Thursday?

During the summer of 2011, a team of BTO staff, collectively known as The Swamp Things (AKA Dave Leech, Lee Barber, Rachael Portnall, Mike Toms and Jez Blackburn), decided that the best way to spend their free time would be to slip into a pair chest waders and wander the reedbeds of Norfolk. Why, you ask? A good question, especially when the temperature rises into the high twenties and the horseflies are hungry, but there was method in their madness as there really is no other way to collect data on the nesting success of Reed Warblers.

So, when the warblers arrived back from Africa in April, The Swamp Things sprang into action, catching and ringing the adults, finding their nests and ringing the chicks. The first full clutch of eggs was recorded on the 8th May, and the last nestling was ringed on the 12th August, by which time several of the team were looking considerably sleeker and, at least from the shoulders up, more tanned. In the intervening three months, they monitored 257 nests and ringed 596 nestlings. An added bonus was provided by the 12 nests parasitized by Cuckoos, of which at least seven were thought to have fledged (and by now have presumably joined Clement , Martin, Caspar, Lyster, and Chris on their wintering grounds).

The seven birds mentioned at the top of this posting were all ringed as chicks in the nest between the 8th and the 30th July and are still finishing their moult and building up their fat reserves. By adding this information to the other recaptures of ringed nestlings, the team will be able to learn a lot more about the behaviour of the youngsters when they reach independence and prepare for their first ever migration, an incredibly important, yet seldom studied, period in their lives.

Thanks to Dave Leech for this post.

Warbler wanderings

Ringing warblers in the summer is always exciting and the data collected is very valuable, especially when they are ringed as chicks or biometrics are taken.

The top warblers ringed in 2010 were Blackcap, Reed Warbler, Chiffchaff, Sedge Warbler and Willow Warbler, all with more than 30,000 birds ringed. These are a mix of long and short distance migrants. We have had reasonable number of Sedge Warbler recoveries from other countries so far (summaries below taken from the Online Ringing Reports). Also click here to see Sedge Warbler recovery totals per country.

Here in the Demography Team, we have just heard about Sedge Warbler T796371. This bird was ringed as a juvenile on 4th August at Hollesley, Suffolk (blue pin). It was then caught in The Netherlands on 13th August (awaiting ringing details, pink pin). Amazingly this bird was then caught on its southward migration on 18th August in Melsele, Oost-Vlaanderen, Belgium (green pin). Three countries in a couple of weeks, not bad by anyone's standard.

View Sedge Warbler tour in a larger map

Hopefully this bird will now head south to its wintering grounds and with increasing ringing in Africa, it is becoming more likely that we will be getting a clearer picture of their movements.

Thanks to Dawn Balmer for the photo.

Just nipping to Spain

In 2010 our ringing scheme ringed 2,331 Redshank and lots of these birds have gone on to be seen or recovered in other countries. Foreign ringed Redshank are found less frequently in this country. Click here to see recovery reports in more detail.

Redshank, 3M009051, was ringed and colour ringed on 13th February 2011 as a juvenile at Fianteira, Sanxenxo, Spain (42'27N 8'50W), (blue pin). This bird was seen at this location up to the 20th March and was then reported to us being seen alive at Seaforth Nature Reserve, Liverpool (red pin) on 27th April (1296km). This is the first Spanish ringed Redshank to be recorded in the UK!

View 1st Spanish ringed Redshank in a larger map

Interestingly it was then seen very close to where it was colour ringed on 29th July (green pin). This bird must have been wintering in Spain and recorded on its migration north to breed. There has been quite a lot of movement of birds between the UK and Iceland to the north, and the UK and France to the south but very little further south than this.

Thanks to Richard du Feu for letting us know about this.