12 April 2016

Do Blue Tits move very far?... Generally no.

Ian and Sally Hunter from the Sandwich Bay Bird Observatory write:

Small groups of Blue or Great Tits, with the occasional Coal Tit, moving southwards along the seafront are not uncommon during visible migration observation at Sandwich Bay.

Despite 10,381 Blue Tits having being ringed by the observatory, we have not really discovered much about their movements. Until 23rd March 2016 the observatory only had one foreign control (ringed abroad), from the Netherlands, and one foreign recovery (found abroad), to the Pas de Calais region of France. Other movements were usually within Kent (19 birds), mostly to/from coastal sites, with six to/from other southern counties. The BTO ringing scheme as a whole has only had an extremely small number crossing the channel.

Blue Tit recoveries involving Britain & Ireland
Colour of location: Ringed in Britain & Ireland, Found Here; Ringed Here, Found in Britain & Ireland
So when a Blue Tit wearing a Lithuanian ring was captured, there was plenty of excitement. The bird was noticeably brighter blue than local birds. Its wing was a big 70 mm and it weighed 11 grams (average for British Blue Tit is 63mm wing and 10 grams). Interestingly the previous day a white headed northern race Long-tailed Tit had been observed and two days later a continental Coal Tit was ringed.

Lithuanian Blue Tit. Photo by Becky Johnson
The map below shows just how far this bird has travelled from Ventes Ragas, Silute distr. It was ringed as an adult Blue Tit at 13:00 on 15 Sept 2015 (nearly 1,400 km in about 6 months).

08 April 2016

First British-ringed Stonechat for Norway - rubicolus?

John Secker from Thetford Forest Ringing Group writes:

Since 2003, Stonechat breeding in the Forestry Commission’s Thetford forest on the Norfolk/Suffolk border have been surveyed. The population has been as high as 56 pairs (2008, after a run of mild winters), and down to just four pairs (2014 after a run of relatively cold winters). In 2006 a project to find nests, and colour-ring both chicks and adults was begun by Thetford Forest Ringing Group.  In total, 750 birds have since been fitted with combinations of three colour rings and a metal BTO ring; 673 have been nestlings, 37 adults and 20 fledglings.

There have been many re-sightings within the forest area and Breckland generally, but also eight from further afield, mostly within East Anglia. The furthest travelled bird being seen near Chingford, East London. But certainly, nothing prepared us for what was to come.

Stonechat - photo taken by Odd Kindburg in Norway

On 27 March 2016 two birders (Odd Kindberg and Fredrik Tjessem) photographed, and reported to the BTO, a colour-ringed female Stonechat, near Tangvall, Sogne, in Southern Norway. The bird had a pink ring above a pale blue on the left leg and metal above pale blue on the right. The combination certainly matched one used in Thetford Forest but all the same, although we could not find any other studies that might have used this combination, we had to wonder whether or not someone closer to Norway may have colour ringing this bird. But from what we could make out from the photos, the metal ring did look tantalisingly like a BTO ring. We got back in touch with the photographers and in no time at all Odd was back on the case and we soon received a new batch of excellent photographs that enabled the entire ring number to be pieced together and therefore rule out any confusion with other studies – BINGO!.

Records showed that this bird was from a nest found by Gavin Chambers in May 2015 near Grimes Graves in Thetford Forest, Norfolk. The chicks were ringed by Ron Hoblyn and me, and the nest fledged successfully. Tangvall is approximately 750 kms North-east of Grimes Graves.
None of the other birds recorded away from Breckland has moved in a north-east or easterly direction.

This is the first ever British-ringed Stonechat to have been reported from Norway. Stonechat was not found breeding in Norway until the 1970’s, when a population of the British race, Saxicola rubicola hibernans established itself. It was speculated that those birds were of Scottish origin, Scotland being the closest part of Britain to southern Norway. But maybe this new record suggests an alternative.

Stonechat showing the three coloured rings - photo by Odd Kindburg

It is possible that the bird became caught up in one of the powerful south-westerly storms that have swept Britain this winter, but perhaps more likely that it made the shorter crossing to the Netherlands and then moved north into Norway. Either way it is a fantastic record and demonstrates the possible rewards to be had from colour-ringing birds.

It will be interesting to find out whether or not this individual stays to breed in Norway.

23 March 2016

East-West Kingfisher Connection

Here in Thetford we are spoilt by sightings of Kingfishers on our daily strolls into the town centre. As we have blogged before, our breeding birds are residents but the birds that we spot in winter may throw a few surprises.

Such was the case of the sixth recovery of a Kingfisher ringed in Germany that has been reported to us. Whilst it may not be the first or the second from Germany, looking at it in more detail we realised that this was a truly remarkable record. The details were brought to our attention by Dr Martin Flade from DDA who ringed the bird on the 23 July 2015 at Lake Brodowin (Brodowinsee) in the Schorfheide-Chorin Biosphere Reserve in Brandenburg, Northeast Germany, only 12 km from the Polish border.

As can be appreciated from the aerial photographs, kindly supplied by Reiner Krause, the area has a very low human population and encompasses about 240 lakes where Kingfishers typically nest on fallen trees.

German adult male Kingfishers are mostly sedentary, but juveniles and females move. Juveniles leave their nesting area a few days after fledging. One German-born juvenile Kingfisher was recovered on Malta only 22 days after it was ringed as a nestling. Another German bird was recovered as far south as Algeria.

The bird that prompted us to write this post was a juvenile female that was found in Market Harborough, Leicestershire, after having hit a window, and it is remarkable for being the furthest east-west movement recorded by any kingfisher ringed in Germany, as shown in the map below.

Landelin (Martin's son) and Yuma ringing Kingfishers in Lake Brodowin
This is an impressive 1,005 km east-west journey that intrigued us and made us look at the Online Ringing & Nest Recording Report to find out how this movement rates against other east-west Kingfisher movements. As shown in the recoveries map below, there is a yellow dot in Poland of a bird that was ringed on the 06/07/2011 in Rz Drawa, Bogdanka, Drawno, Poland and controlled by ringers on the 25/11/2011 in Orfordness; this bird was also a female. Despite coming from further east, the bird ringed in Poland 'only travelled' 972 km in 81 days, so we can say that the bird ringed by Dr Martin Flade is number one on our east-west Kingfisher connection.

The eastern most yellow dot is the bird ringed in Poland and this post's bird is not showing on this map yet.

Many thanks to Dr Martin Flade for highlighting the relevance of this recovery and for supplying the photographs and very interesting information about German ringed Kingfishers. Martin organised the German BBS from 1989 to 2010. He was also a member of the EBCC (European Bird Census Council).

07 March 2016

Getting more from your birding

Here at the BTO we engage with countless local birders as well as ringers and nest recorders. A lot of important work is undertaken by birders across the length and breadth of Britain & Ireland. One such birder is Lee Collins who writes:

My local patch at Dawlish Warren NNR in South Devon has, over the last three years, achieved some amazing success in generating large numbers of field reads of gulls, terns and waders; my efforts over 2014 were summarized on the Demog blog in May 2015. I am not a ringer, in fact no ringing is currently done on the site (although some ringing was done previously), yet with a positive mind-set, high on-site attendance accompanied with bundles of enthusiasm, anyone can achieve amazing results with ring reading.

Dawlish Warren NNR is a coastal reserve with a  long and rich history in birding terms and I'm proud to have called this my local patch since 1984. On-site breeding of gulls, terns and waders is non-existent and thus ring reads are generally confined to the winter months, although the months of July and August do also provide a bumper opportunity with the onset of post breeding dispersal.

I have just finished writing a detailed 38 page article on my efforts over 2015. In total I've record 429 field reads, comprising 16 species and involving 219 different individuals. Here’s a brief resume of the highlights.

Dawlish Warren. Taken by Lee Collins

The standout single read was in securing my second ever Roseate Tern ring. This bird was ringed at Rockabill, Ireland in 2013 and the read may be the only recovery of this species in the Britain & Ireland during 2015 away from their breeding colonies. Terns are of particular interest to me and although no breeding occurs, I see good numbers of 200+ Sandwich Terns present during July and August. During this periods it is a hive of activity, with birds coming and going as they feed offshore and drop back in to roost or to feed their fledged young in front of the hide.

I made 61 reads during this nine week period, securing positive reads on 35 different individuals (30 adults and five juveniles). The reads were a combination of colour rings (15) and the more difficult to read metal ringed birds (20).

Frustratingly, not a single bird recorded on the site was to provide information on where they bred during 2015, although most probably nested several hundred kilometres away. Importantly, there is a good rate of multi-year observations of several individual birds recorded on-site during 2013 and 2014. The results suggest the Warren plays an important role as a staging and feeding area during post breeding dispersal.

Sandwich Tern taken by Lee Collins

The majority of Sandwich Tern ringing locations were in Scotland (750+ km away) and the Netherlands (600 km away), although others also range from Poland to Ireland. The Polish-ringed Sandwich Tern is particularly noteworthy as it looks to be the first recorded in Britain & Ireland.

Sanderling taken by Lee Collins

Waders are of particular importance and are abundant on the reserve. Sanderling in particular are of interest due to their long-distance migratory pattern and I found ten different colour ringed individuals during 2015. Most birds were seen during the month of May as they headed north to breeding grounds in Greenland. These birds were ringed in Greenland, Iceland or Mauritania.

Ringed Plover taken by Lee Collins

Ringed Plover is an abundant species in Devon, yet with a poor recovery history. I recorded seven in 2015, which is almost double the entire recovery history for the county. These were found during the autumn, presumably passage migrants dropping in to refuel. Unsurprisingly, a few were from Iceland, but several were from Norway and a one was from Germany.

Despite these impressive recoveries, my most important work is in fact dedicated to a species that receives little attention from practically all the birders that visit the site, the Oystercatcher. Over a three year period I have made almost 270 positive metal ring reads involving 116 different individuals, with 77 different birds recorded during 2015 alone.

The vast majority (91%) of these were ringed on-site, as part of a study programme undertaken between 1976 and 2004. The movements recorded may not be very far but this provides invaluable data on longevity and survival of this species, especially as it is now amber listed. I have recorded over a dozen individuals that were at least 25 years old, plus another that was ringed in 1983, making it at least 32 years old!

If you wish to read more, you can read Lee's full article on the Dawlish Warren blog.

26 February 2016

What happened to all the Jays?

Around the UK, Jays haven’t needed to dip into their large cache of acorns much this winter, with the weather being so mild. They will top up their diet with invertebrates and any other meaty treats they can get. This search can lead them to gardens during cold periods and some of these gardens are occupied by BTO ringers.

Jay taken by John Flowerday

Last year our BTO ringers ringed 506 Jays in the Britain & Ireland (c700 is the five year average) and as Jays can live to a maximum of 16 years old, there are a good number of ringed Jays in the wild population. Being very clever birds, they can provide a challenge to ringers to catch them but once caught they deserve respect as they are incredibly powerful birds with very sharp claws and beaks. Once in the ringers hands the birds are ringed, aged, and several measurements taken to record the condition the bird and if any moult or breeding is occurring.

Jay taken by Lee Barber

Thankfully 89% of the reports of ringed Jays come from our ringers by re-catching them, months or even years later. This information is vital to understanding the movements, behaviour and survival of this beautiful bird. Ringed Jays are also found by non-ringers, which usually report them through www.ring.ac website.

Most of these birds are just found dead with no cause of death given, however a large proportion are legally shot/trapped with the aim of reducing their impact on other species nesting attempts. The Jay is not without its own predators however, as 6% of ringed birds reported to the BTO have been taken by a predator. Even the Peregrine is a little partial to the odd Jay as a recent BTO Demog Blog post can testify.