100,000 encounters

Richard du Feu writes:

On the 17th December 1972 John McMeeking made his first ringing visit to Treswell Wood, Nottingham. Soon afterwards systematic ringing began covering seven standard sites around the wood along with visits to additional rides when time allowed. 41 years less two days later the 100,000th encounter (ringed and already ringed) record of birds ringed within the wood was made. Rather fittingly this bird was a Treecreeper which has been the logo of the group for the last few years. The photo below is of John McMeeking holding encounter number 100,000. Remarkably this was one of six Treecreepers caught simultaneously within 30 metres of netting.

John McMeeking with a Treecreeper - taken by John Clark

Initially John had said he wanted to find out what was in the wood and maybe get a paper or two out of ringing in the wood. It is safe to say that the latter has happened. The most noteworthy of these papers was the first paper to show that CES (Constant Effort Site) data did successfully monitor juvenile abundance. The various papers have only been possible because of the continual systematic monitoring, recording and hard work of all the CBC (Common Bird Census) recorders, nest recorders and ringers.

Updated 22/12/2013.

Lost(?) Snow Bunting in France

With a chill in the air, it only seems right that we've just received details of a very bizarre Snow Bunting movement... With the aid of some excellent photos, we were able to read the ring of VX35928, seen on 22nd November at Moosch, France, right on the French/Swiss/German border.

VX35928 in northeast France in November

Interestingly, this bird had been ringed by East Norfolk Ringing Group as a young male at Eccles on Sea, Norfolk, just six days previously! It is interesting to think where these East Anglian birds are coming from, and as the two races can be identified on plumage (easier in the hand!), studies have shown that 80% of females in East Anglia are from Iceland whereas 80% of males are from Scandinavia (or Greenland).

The only other British-ringed Snow Bunting found in France was, more typically, found on the Belgian border, but an inland record so far east is almost unprecedented. There is one slightly more bizarre record, which bears many similarities with this recent record. AC96749 (also a young male) was ringed at Walberswick, Suffolk, on 4th November 1962 and shot just 14 days later in northeast Italy. So the fact these were both males and found so far east presumably means they were both Scandinavian birds wanting to winter more to the east than the UK...

All movements of Snow Buntings to/from Britain, with VX35928 in red

Having said that... the East Norfolk Ringing Group obviously do see birds from both races, as they caught the bird below on 8th December, wearing a shiny Icelandic ring! This is a bit more expected, with almost 50 exchanges between here and Iceland.

Many thanks to Marc Solari for the photos of the bird in France to allow us to read the ring and to Dave Andrews for the photo of the Icelandic-ringed bird.

Demog Blog at Swanwick

OK, so whilst 'Demog Blog' itself won't be physically appearing at Swanwick this weekend, it will be making a guest appearance in a 'Social Media' talk on Sunday morning. So keep an eye out for it then and say hi if you're attending!

Speaking of all things social media, we thought we'd take this opportunity to shamelessly plug a few of the other BTO social media sites and some of the blogs we follow. The BTO itself exists on Facebook, Twitter and YouTube, so why not like/follow/subscribe to keep up-to-date on what's going on in the BTO world. There are also various surveys on Twitter, including BirdTrack, Garden BirdWatch and WeBS.

On the blog front, if you've not already noticed, then check out the list of related blogs in the right-hand pane (unless you're reading this on a reader or on your phone!). Whilst it's not fair to pick out any blogs in particular, why not browse the list and see what takes your fancy. Recent posts on some of the regulars include portable Helgoland traps, Siberian Chiffchaffs, Dartford Warblers, hidden Kittiwake colonies, a Scandinavian invasion, Belgian Redwing, dawn to dusk ringing, and another cross-billed Blue Tit!

Bardsey Bird Observatory's versatile portable Helgoland trap

Another bizarre Blue Tit - this time on Peter Alker's blog

If you have a ringing-related blog yourself that doesn't feature on Demog Blog then let us know and we'll add you to the list. If you don't have a blog, but do have a story to tell, then you know where we are (ringing@bto.org).

Crossbill, Avocet or Wrybill?

Beak deformities in wild birds are unusual, with fewer than one in 200 adult birds thought to be affected. As long as the bird can feed and preen once a bill is deformed enough that the tip isn't constantly worn away, it can grow to amazing lengths.

Juvenile Blue Tit with the a bill deformity. Ipsley Alders Nature Reserve, Mike Barstow

Whilst ringing at Ipsley Alders Nature Reserve, Redditch, Mike Barstow retrapped a Blue Tit on 25/11/2013 that he previously ringed on 19/01/2012 with no deformity noted. This bird now had a severely deformed bill (below). The bird appeared healthy with good plumage, muscle and even had a trace of fat. There are therefore two birds (above and below) that have been recorded at this site which have developed a beak deformity within a few years.The research continues.

Adult Blue Tit. Ipsley Alders Nature Reserve, Mike Barstow

Measuring bill length to investigate growth rate for future captures- Mike Barstow

 Types of beak deformities in the wild:

• Crossed mandibles: similar to that of a Common Crossbill perhaps caused by slight asymmetry of the jaw. Straight beaks have been recorded as a deformity in Crossbills.

• Decurved upper mandible: can occur when the tip of the lower mandible is damaged so that the beak does not close correctly.

• Upcurved lower mandible: may occur when the tip of the upper mandible is missing (i.e. broken off).

• Elongation of both mandibles: produces ‘Curlew-type’ beaks, although the degree of curvature varies considerably between individuals.

• Bent to the side: seemingly uncommon, with one or other mandible warping sideways.

• Gapped: where the upper and lower mandibles do not close fully leaving a visible gap.

For more information click here

Wandering Caspian Gulls

We don't have many recoveries of Caspian Gulls and the ones we do get are colour-ring sightings of foreign-ringed birds: most are from Poland (62), with smaller numbers from Ukraine (8) and singles from Germany and Switzerland. But we have only recently started seeing reports from abroad of British-ringed Caspian Gulls and these have all involved birds ringed by the North Thames Gull Group at either Pitsea Tip (Essex) or Rainham Tip (London). A young bird ringed in December 2011 spent most of spring 2012 on Texel (The Netherlands) and another young bird ringed in October 2011 was seen at Blaringham (France) and Neeltje Jans (The Netherlands) over the rest of that winter and then on and off until March 2013. But perhaps the most interesting is GG61181 (Orange PR6T); ringed as a second-winter bird at Pitsea Tip in February 2010.

GG61181 at Pitsea in February 2010

PR6T was then seen in Germany in December 2011 and this east-west migration of Caspian Gulls seems to be the norm. True to form PR6T was then recently seen again, but this time in The Netherlands, on Terschelling Island on 18th November.

GG61181 in The Netherlands last week

Once again this highlights the kind of information that can be gained from colour-ringing studies, all of which rely on the support of the wider birding community in looking for and reporting these birds. Full details for this bird (and further photos) can be found on the North Thames Gull Group website, where you can also report any NTGG birds seen. Thanks to Paul Roper from the group for passing on this story and for the photos of he bird in the hand, and to Jacob de Vries for the photo of the bird in The Netherlands.