A Tale of Two Bitterns

On the 8th May 2000 a brood of Bitterns were ringed at Leighton Moss by the RSPB Research Staff, they were sexed using DNA technology. In the years since then ringed Bitterns have been seen regularly at Leighton Moss. It was thought that only one bird had survived for the ring numbers could not be read.
However with the recent advances in digital photography and digiscoping it has been possible to read the ring numbers and it has now been definitely proved that there are two ringed Bitterns, both female on DNA evidence at the time of ringing.

1291703 has been only seen from the Jackson and Griesdale Hides at the western end of the Reserve. It appears to be the female that has nested in this area for several years. Its sibling 02 (see photo) has only been positively identified from the Lower and Public Hides at the eastern end of the Reserve. So it appears on present evidence that these two birds have different ranges within the reserve. 02 has only been positively identified between late autumn and early winter. However Elaine and Eddie Prince saw a ringed bird at the Lower Hide on July 5th 2007 but could not see the critical part of the ring. Also on 28th September 2007 they saw two ringed Bitterns at the Lower Hide on an occasion when the Jackson and Griesdale meres were disturbed by Reserve staff undertaking habitat management work but no details of the rings could be seen.

It is amazing that both these females have survived so long and at 8 and a half plus years they are the oldest Bitterns recorded by the British Ringing Scheme. One rather worrying aspect is the question as too what extent there is inbreeding within this tiny and isolated population.

Many thanks to all those observers who have photographed or observed the birds. Please continue to pass any sightings to the reserve staff.

Heysham Waders

On Friday an excellent catch of 461 Oystercatchers was made at Heysham Helipad. Of these just 13 carried rings including a bird with an Icelandic ring. Weights and measurements were taken from about half the birds including the extent of moult. The bulk of birds (99%) had more or less completed their main flight feather moult strongly suggesting that the birds roosting at Heysham are in good condition even though large quantities of mussel spat have been removed from their feeding grounds this autumn.

Of the 13 ringed birds 6 were ringed at Heysham between 2001 and 2006. Another was ringed as an immature bird in South Wales in November 2004. The final bird we have details for was ringed as a chick in Northumberland and caught at Heysham in 2001.

On Thursday and Friday sightings of 7 colour ringed Knot were made at Heysham and near naze. Of these 5 were seen last winter and two are new to the bay. All of them have been ringed within the last 8 years on the Waddensea by NIOZ (http://www.nioz.nl/). Please keep an eye open for colour ringed waders as there are very few observers in the bay and provide huge amounts of information about the use of Morecambe bay.

Recent Waxwing information

Anyone reading this, please carefully check any Waxwings for colour rings - Mark has led the way with the Barrow (Clitheroe) bird & note that Raymond suggests movement in the next few days, possibly/probably including some more in this area. Some nice public relations etc. on the Cumbrian (Dalston) link in Raymond's letter. All schools should plant ornamental rowans - some great lesson plans every few years!

Birds appear to be moving through quite rapidly with few left around Aberdeen now. There are a lot already in Ireland (per pager etc.) as there appears to be quite a bit of 'west' in the SW movement, with relatively few birds at traditional eastern England locations. That may be good news for this area, as suggested so far.........or the rest of the birds to the north of us may end up in Ireland. In this respect, Edinburgh & the "Central Belt" (where there are quite a few at present) is west of Carlisle!

Here are the longer distance recoveries on Raymond Duncan's PDF - I wasnt quite sure of the resighting history around Aberdeen and therefore the number of days involved in the actual movement for some of them.

09/11/08 Scotstown Rd, B of Don, Aberdeen
17/11/08 Peebles, Scottish Borders Hit window 8 days

09/11/08 Scotstown Rd, B of Don, Aberdeen
21/11/08 Resighting Barrow, Lancashire 12 days

09/11/08 Scotstown Rd, B of Don, Aberdeen
26/11/08 Resighting 17 days Alnwick, Northumberland

09/11-08 Scotstown Rd, B of Don, Aberdeen (& resightings in area?)08/12/08 Resighting Ramsey, Isle of Man (after being seen at Crieff? - not sure about this bird exact details)

13/11/08 Marriot Hotel, Dyce, Aberdeen (& resightings in area?)08/12/08 Resighting Longtown, Cumbria

22/11/08 Bedford Rd, Aberdeen University
09/12/08 Resighting 17 days Dalston, Cumbria 21/11/08

One solitary bird was ringed at Gibraltar Point and then subsequently seen at Lincoln

Raymond's letter:
"Hard to believe it's only just over a month since we had our first waxwing catches in Orkney and Aberdeen. All have gone from Orkney and we appear to have only scattered groups left in Aberdeen. It has all happened so quickly this winter. We are missing them already (but the mistle thrushes aren't)!

Many thanks to all observers for their sightings and photographs. It's been very exciting receiving your records. Update number 2 is attached. 5 sightings by RSPB Edinburgh in a lunchtime was great but these large flocks in the Central Belt appear to be breaking up and continuing on south. Big influx into Cumbria at the weekend (2 sightings) and note ORO's cross country movement to Isle of Man...next stop Ireland?
Link below to a wee story by David Hickson on the waxwings in Dalston, Cumbria....Ian Armstrong now has some colour-rings to hopefully ring some more before they move on again.

http://www.dalston.org.uk/Photography/Waxwings/index.cfm

Please forward on to anybody you think might be interested and alert them to look out for colour-rings.

Many thanks again.

Best wishes,

Raymond Duncan
(Grampian Ringing Group secretary)"

Reed Warblers in 2008

A cold and frosty outlook was just the day to be transported back to spring through to late summer and finish our report on this years Reed Warbler study at Leighton Moss. The weather then was certainly warmer than now, but the season was dominated by periods of heavy rain resulting in high water levels along with a short period of gale force winds which certainly blew out many early nests. Although we manged 51 ringing visits the unseasonable weather meant this was 16 less than in 2007. The Reed Warbler study is a spin off from our Bearded Tit study where we try to maintain similar effort from year to year.

In total we caught 153 adult Reed Warblers down from 206 the previous year but just below average for the 12 years of the study. Many of these were already ringed the oldest was in its 8th year. This is still somewhat behind our oldest record of 9 years and 293 days. What an amazing distance that bird must have flown to West Africa and back at least 9 times! Including of course crossing the Sahara.

Productivity started off very poor following the period of high winds mentioned above but it picked up later in the season despite the heavy rains. So that by the end of September we had ringed 472 young birds giving a slightly below average catch compared with the 11 other years.

John Wilson

Where Have All the Blue Tits Gone ?

One of my reasons for finding ringing so interesting is that you can put some tangible figures on the population levels and productivity of some of our commonest birds.

Many garden bird enthusiasts have commented to me that there seems fewer Blue Tits in their gardens this winter. Do our ringing returns support this view?
A trawl through our database came up with the following figures for our ringing of Blue Tits at Leighton Moss.

2006 480
2007 338
2008 242

So yes 2008 has been a very poor year. Perhaps even more telling is the proportion of adult birds in the catch. Adult and first year Blue Tits can easily and reliably be told apart in the hand because the young birds retain the greenish juvenile feathers on the primary coverts.
In 2006 only 7 % of the birds we caught were adults, a sure sign that productivity was high. In 2007 this increased to 21% and this year to 25%. So the last two years have seen low productivity mainly due to the unusually wet weather either during or just after the nesting season, making invertebrate food hard to find and so causing high mortality among the young inexperienced birds. The Leighton birds were caught in the scrub and reed bed areas and were not taking artificial food.

A catch today of 35 Blue Tits at a feeding station in Arkholme produced an amazing 55% of adult birds. The high numbers may partly be explained by adults relying on their knowledge of a good feeding station and so returning in succesive years whereas young birds have to discover the good sites for the first time. It was also noticeable in this admittidly small sample that adult birds were on average a gram heavier that young birds.

One side line to this is that Coal Tit numbers have been the highest on record with lots of young birds. Coal tits nest mainly in conifer areas and also nest somewhat earlier than blue tits so may have escaped the worst of the bad weather.

John Wilson

Winter in the woods

One of the great joys of bird ringing is that you never know what you will find in the net (or even if you will find anything at all!) Saturday, November 29, 2008 was just one of those days - one where the unexpected turned up rather than nothing!
I'd anticipated that the weather would be calm and fine and so had put out some feeders in a private area of woodland near the Lune Valley but had had trouble getting out of bed early after a hard week's work, so got to the wood a bit later than expected. Worse, the birds had eaten all the seeds I'd put out and it was bright sunshine - in such circumstances it is not uncommon to draw a blank as far as catching is concerened and I had no high hopes of doing anything other than sitting in the wood and relaxing. How wrong could I be?
It turned out to be one of the busiest mornings I've had, even though I only used one net - the birds were positively enthusiastic about jumping into the net, even as I was putting it up and for the next three hours I was kept nice and busy.
Highlights of the morning included three Nuthatch, including one with a deformed bill - the upper mandible was almost a centimetre shorter than the lower mandible and skewed slightly to one side, but it obviously had little difficulty in feeding itself as it appeared to be an adult - I say "appeared to be" as they are rather tricky to age.
However, nice though Nuthatch are, undoubtably the best bird was a Marsh Tit - the first I've caught in over 15 years ringing. Marsh Tit are not easy birds to see in our area, so this will be a useful bird for us to record as part of the BTO bird atlas. Other birds ringed included 30 Blue Tit (plus 4 ringed by me in this valley as pulli), 14 Great Tit (plus 5 ringed birds and one possibly from somewhere else), 15 Coal Tit (plus 1 ringed and 1 other), 2 Robin and single Chaffinch, Dunnock and Treecreeper.
Ringing helps us to assess and record the importance of such woodland for breeding and wintering birds and this morning helped build up a scientific record of just how important such woods are for the diversity and abundance of birds in our area.
The only downside was that it was so cold that my camera wouldn't work so I couldn't photograph anything!
Are these yours? TH22759 - Great Tit, TH43033 - Nuthatch, V439178 - Coal Tit.

Regards

Paul Cammack