Recent Recoveries

A new batch of recoveries from the BTO included some interesting records.
The longest distance travelled was a Lesser Redpoll ringed at Heysham on April 13th on spring passage and caught by a ringer 334 km to the south east in Surry on 23/11/10. Was this its wintering location or was it still on passage?

Perhaps the most bizarre record was of a Goldcrest ringed at Leighton Moss on October 20th and found dead 27 days and 94 km to the ESE at Wakefield in Yorkshire Just shows how random some bird movements can be.

A twite ringed at Heysham on March 8th 2010 was caught on Sanda Island off the Mull of Kintyre in July 2010, This is the seventh Twite we have had from,
the ringing site on Sanda along with three others from the same general area, showing it to be one of the main breeding areas of our wintering flock.

In the same batch of recoveries we had four Blue Tits, all ringed as neslings in the nest box sschemes we run in the upland woods on the south of the Lune valley. They showed movements to towns and villages of up to 16 km. Two birds ringed on the same day in late May (but from different broods) were caught together in mid October at a feeding station. A coal Tit nestling ringed in the same wood had also moved out of the upland woods travelling 16 km to a feeding station.

Twite - New versus Unringed

A whoosh net catch of twite taken this morning at Heysham Harbour consisted of what at first seemed a high proportion of unringed birds, compared to that observed over recent weeks. The catch, of 37 birds, comprised 21 unringed and 16 retraps. Recent counts have suggested only 16 unringed birds out of various flocks totalling close to 80.

This is actually not so surprising, when the circumstances are revealed. Time was short this morning so I only wanted to deal with one catch. In addition, the wind was gusty and becoming stronger all the time. Whilst setting the net, groups of Twite were flying about above me and when finished I walked towards the car to fetch some fresh seed. Immediately, birds began to line up on the fence and even drop onto the seed already there.

A large group of birds quickly gathered on the seed - after waiting for a safe gap in the arriving birds the net was fired, with many more still on the fence. This is not usually a good idea if further catches are intended.

However, it does clearly show that unringed birds (that have not encountered a whoosh net before) are less wary of the net paraphernalia and the "old hands" take their time before dropping in. The retrapped birds had all been ringed in 2010 - no older birds were recaught.

This is not surprising really, but does show that care might be required when undertaking analyses of retrap information.

ajd

Heysham Oystercatchers

On Saturday we had a catch of Oystercatchers at Heysham Helipad. A total of 217 were caught and ringed. This is a lower total than on the previous two Oystercatcher catches (see here and here) however gave us significant amounts of biometric data.

Last year I commented on the lack of juvenile birds in the catch (just 1 out of 569) suggesting a complete wipe out of juveniles in the bay last winter. In the catch over the weekend we caught 10 birds that hatched in 2009 suggesting that rather than being wiped out in the bay the juveniles were actually feeding in land while the birds in better condition roosted. This year we caught 19 juvenile birds which is higher than I expected given the recent cold weather.

With over 1,000 Oystercatchers ringed at Heysham over the last 2 winters I had hoped for some more retraps to help create a reasonable survival estimate. With just 9 retraps this is difficult. Perhaps it is more an indication of the number of birds roosting at Heysham and the surrounding area (a simple lincoln index gives us a figure of 20,000 birds using the site). Last winter we noted ingress of east coast Oystercatchers so it is possible many of last winters birds have moved back to their traditional wintering grounds.

One bird retrapped at Heysham was ringed on 27/3/2010 near Tarland, Grampian at a spring inland roost site. This gives me a great deal of encouragement as our ringing of inland Oystercatchers at spring roosts have so far generated no movements away from ringing sites!

Most recent recoveries from Heysham of Oystercatchers show the birds roosting at Heysham breed on the west coast of Scotland, Orkney, Shetland, Faeroes and Iceland.

Finally I have managed to do a quick bit of analysis of the data and produced a graph which is below. It shows the cumulative distribution of weights for adult Oystercatchers caught on 12/12/2008, 01/02/2010 and 22/01/2011 at Heysham. The 2008 weights are lowest which is no surprise as the birds will have just completed their moult. The 2010 weights are on average about 15 grams less than the 2011 weights for catches essentially at the same part of the winter. In both 2010 and 2011 the catches were made after severe weather, in 2010 about a week after the cold spell ended, in 2011 about 2 weeks after.



Thanks to:
Raymond Duncan (Grampian Waxwing Group) and everyone who helped with this catch. If you want to see some photos visit Fleetwood birder's blog

Richard

Mobile Black-tailed Godwits

Two recent colour ringed sightings of Black-tailed Godwits throw further light on their movements between estuaries. Both were ringed during the breeding season in Iceland making a total of 19 to date from the breeding grounds.

YN-RX shows just how mobile they can be on the wintering area. It was ringed as an adult male on 11th July 2009 in Iceland and first seen on the Dee estuary on 20th September and seen almost daily there for the next eight days. It then appeared on the Eric Morecambe Complex near Leighton Moss on October 5th, was back on the Dee on October 8th then on the Eric Morecambe Complex again on 11th October.

This is not the first bird to show similar movements. Another adult male was seen on the Eric Morecambe Complex on September 26th was on the Dee on October 9th and back on the Eric Morecambe Complex on 17 October.

These birds were probably on migration and although good numbers winter on the estuaries of North West England. Colour ringing has shown that many move on and winter in Ireland France and Portugal.

John

2010 a Record Year

With just over 12,600 new birds ringed in 2010 making it the highest total since the group was established and over 5,500 up on 2009.
In total with re-traps and controls we handled nearly 16500 birds of 78 species. This good total partly reflects more effort helped by better weather but it also reflects an excellent breeding season for many species.
Much of our effort during the spring and summer goes into our four Re-trapping Adults for Survival (RAS) projects.
Sand Martins on the River Lune with 1659 new birds and 446 re-traps heads the list.
Our Reed Warbler study at Leighton Moss with 897 caught of which 249 were re-traps is in its tenth year. This year saw the third highest number of adults caught.
Pied Flycatchers are ringed in the nest boxes in the Lune valley Oak Woods. This year we had 63 occupied nest boxes and ringed 308 nestlings and caught 67 adults of which 40 had been ringed in previous years
Bearded Tits at Leighton Moss had a successful season with 104 young birds ringed and an amazing 1062 re-traps or sightings of our colour ringed birds . In total 761 were sightings mainly on the grit trays.

In other projects we ringed 1422 Swallows mainly in a maize field roost. Wintering Twite at Heysham . have been studied for several years this year we caught 238, But the bird heading the list of most ringed bird was Blue Tit with 2013 ringed many of them in our nest boxes. It was obviously an excellent breeding season for this species and is all part of the BTO's population monitoring. During the recent cold spell we have had several examples of Blue Tits moving from the upland breeding woodlands to the well stocked feeders in towns. We also re-trapped one which was in its eighth year.
A successful breeding season resulted in peak catches for Willow Warbler (605), Chiffchaff(238), Grasshopper Warbler(32),Long-tailed Tit (399) Goldfinch (532), and Coal Tit (564)
So all told an excellent season, we look forward with interest to 2011, will the severe December weather have cut the numbers of our resident birds? Will the three species of summer visitors that we study return from their African wintering grounds in good numbers? Watch this space!
John