20 February 2012

Jack Snipe for the Year List!

Jack Snipe are a difficult bird to survey, let alone ring, so what are the chances to get a foreign recovery?

A quick look at the online reports shows that the chances of receiving a recovery of a Jack Snipe are pretty slim, with only only a couple of birds recovered in good years (see table). Most of the recoveries are from shot birds.

Ringed and Recovered Jack Snipes, from on-line reports
YearRinged Recovered
201139 0

They are generally only seen when they are flushed at a very short distance and the estimation of total wintering numbers is based on information from the British Association for Shooting and Conservation, not on actual 'in the field' counts. It has been calculated that apparently one Jack Snipe is shot for every 10 Common Snipe (in France and The Netherlands).

I am sure you all will agree with me that Jack Snipe are always a great find, in the field or in the net, and the same goes for processing recoveries. So that is why, so far, the highlight of the month has been a report received from the Hiddensee Bird Ringing Centre with the details of a Jack Snipe ringed as a juvenile in August 2007 in Burgstadt, Sachhsen, Germany. This bird saw the end of its days in St Austell (Cornwall) on the 14.01.2012 when it was shot.

View Jack Snipe for the year list in a larger map

13 February 2012

Where are your Purps from?

I recently heard of a colour-ring sighting of a Purple Sandpiper at Godrevy Island, Cornwall, in late October 2011. This got me thinking, as the origin of the county's wintering birds has interested me since moving down here recently. The only previous recovery in the county was an Icelandic-ringed bird seen at Penzance in November 2004 and May 2005. So it was a bit surprising to find this bird had been ringed on the island of Nidingen off the southwest coast of Sweden in May 2011.

There are two distinct populations of Purple Sandpipers that winter in the UK, of birds breeding in the east (northwest Europe) and west (Canada). These populations have, predictably, rather different wintering areas, as can be seen below. The map shows the country of ringing of birds found in the UK and the predominance of Icelandic-ringed birds (I) in the north and west and Norwegian-ringed birds (N) in the east is obvious. Zoom in to see more detail and click on the map for a key to the other codes.

View Purple Sandpipers in a larger map

The two populations can be identified on biometrics though, with bill length and wing length being of most use. So where are our Cornish birds from? Well with one from Iceland and one from Norway, perhaps only biometrics will tell.

10 February 2012

Belgian Surprise

Orchards are great sources of food for our wintering birds, and also ringing opportunities for ringers. The North Notts Ringing Group was doing just this yesterday, ringing in an orchard. They were mist netting thrushes before the snow started to fall.

They managed to catch 450 birds, with a large proportion being Fieldfare (217 birds). There were also 177 Blackbirds, 15 Redwing and 3 Mistle Thrush caught, along with some other smaller passerines. Unfortunately there were no controls in this catch apart from one, a Blackcap wearing a Belgian ring!

In the last 3 years we have had eight reports of Blackcap being found in this country in January or Feburary. Discounting all of the birds that were ringed originally in the UK, one was from Germany, one from the Channel Islands, two from The Netherlands and four from Belgium. In the past, these Blackcaps might not have survived to migrate back to their country of origin, but due to the recent trend of relatively mild winters and increased garden feeding, these blackcaps are more likely to survive and return to their home country to breed. This increases the population that are 'programmed' to travel to the UK and Ireland for the winter. Hopefully, we will see more continental ringed blackcaps caught here during the winter months.

Thanks to Mark R Taylor for the photo and to Adrian Blackburn for letting us know.

07 February 2012

Black and Gold

Every BTO ringer who has a current ringing licence has a permit number. Trainee ringers have a permit number of 0000 to start with but when they are able to operate with 'remote supervision' (C permit holder) they get issued with another number . This number then stays with them for the rest of their ringing career. The latest permit number to be issued is currently 5866.

Coming from someone whose ringing permit number is after 5000, seeing data going to ringers with permit numbers below 1000 or even 100 is amazing. After Tony Mainwood qualified for his A permit with number 903, the first bird he ringed was a Blackbird on 31st January 1962. Exactly 50 years on, during a routine ringing session on 31st January 2012 he reached this 50 year 'mile stone' by ringing another Blackbird.

We have 64,249 electronic ringing records for Tony (not including all the ringing he has done with other groups). As he started ringing way before the computerisation of ringing records, his total is actually much much more.

Thanks to Jez Blackburn for the photo.

04 February 2012

It's all about the sewage

It’s well known that wintering Chiffchaffs have a great affinity with the southwest, with Devon and Cornwall home to an unknown, but undoubtedly large, proportion of the UK wintering population. Looking back at just the last five winters (December to February in each of 2006-07 to 2010-11), we hold electronic ringing records of 918 Chiffchaffs, with no fewer than 244 ringed in Devon and 187 in Cornwall. Over these years, the highest winter total was 86 birds ringed in Devon in 2008-09.

Despite this winter being relatively mild, we’ve been having great success in catching wintering Chiffchaffs at several sites in Cornwall, thanks largely to the support of South West Water in allowing us access to works areas. Since the start of the year, we’ve ringed 105 Chiffchaffs at just three sewage works in Cornwall, including 41 on one day alone. This compares well to previous years, with the highest winter total nationally being 265 in 2009-10.

The racial identity of these birds is also interesting, with a small proportion being of northern races: either abietinus or tristis (Siberian Chiffchaff, above). Interestingly though, yesterday morning saw us catch a French-ringed bird, perhaps indicating an alternative origin of these wintering birds. There are just 13 previous records of French-ringed Chiffchaffs in the UK, of which three have been in Cornwall and two in Devon.

The sewage works sites are also important for various other wintering species, and yesterday’s catch also included two Firecrests and two Yellow-browed Warblers (below) in amongst the more expected 35 Chiffchaffs. The Yellow-broweds are of particular note, as of the 902 electronic ringing records we hold, just six have been in winter (five in December and one in January).

Thanks to Ashley Hugo for the tristis Chiff photo and Adam Hartley for the Yellow-broweds.

01 February 2012

10 Millionth Milestone

The British and Irish ringing scheme is part of a much wider group of ringing schemes across Europe called the European Union for Bird Ringing (EURING), which was formed nearly 50 years ago. EURING encourages co-operation, common standards and data exchange across Europe.

The EURING databank is currently located at the BTO and its purpose is to collate information on bird demography. This makes data much more accessible for scientific studies. It holds records dating back over 100 years, covering 552 different bird species.

A female Swallow, ringed in Malta (blue pin) has now become famous after being the 10 millionth entry into the EURING databank. It was ringed on 16 April 2011 during passage, and was caught by another ringer during routine ringing operations on 19 June 2011 in Raby, Czech Republic (red pin)!

Recent studies using the EURING data have examined flyways, migratory divides, connectivity, irruption, evolution, phenological changes, moult migration, dispersal of sedentary species and birds as vectors of diseases. Other studies have focussed on survival, mortality, habitat use and population trends.

For more information on EURING see their website.

Thanks to George H Higginbotham for the photo.