Friday 1 November 2019

Copeland Bird Observatory 25-27th October 2019

I embarked on just my third weekend stay of the year to Copeland Bird Observatory on Friday 25th of October accompanied by Pete, Emily and Ed. This is pencilled in to be the final weekend visit of the season so there was lots of work to be done to get the Observatory closed own for the winter e.g. closing up the traps and bringing catching boxes, storing the bedding/pillows etc.

With a forecast of pretty much strong westerlies all weekend and very little having been seen/ringed during the previous 7 days we weren't going in overly optimistic - but at least it was sunny!

The nets were very quiet with a handful of new birds over the weekend but we did hit gold with a Yellow-browed Warbler.

Yellow-browed Warbler

On Friday night we went out for a spot of dazzling and had a few close misses with Redshank but did manage to catch a Curlew, the first to be ringed here in 32 years and a retrap Oystercatcher which was ringed the year previous on the island.


Birds of prey put on a good show with a ring-tailed Hen Harrier quartering the island throughout the weekend and almost flying in to a couple of mist nets. It was joined in the sky by up to four Buzzards at a time and at one stage we had a Sparrowhawk swirling about with them.

Other passage was very limited with a single Redwing, 17 Whooper Swans, 18 Skylark, 1 Lesser Redpoll and the regular cohort of wintering birds. No sea watching was done but there were plenty of Gannets, auks, Kittiwakes passing and one Great Northern Diver was noted passing towards Belfast Lough. Seven Carrion Crow is a good count for Northern Ireland.


The Yellow-browed Warbler on Copeland Bird Observatory 
2019 has proved to be yet another Yellow-browed Warbler (Phylloscopus inornatus) year on CBO for what was once a very rare vagrant for the observatory and Northern Ireland as a whole. Two birds were recorded this season, one sighted on the 11th of October and a second trapped and ringed on 26th October, the 12th & 13th records for CBO. 
Figure 1: Yellow-browed Warbler (Richard Donaghey) 
The Yellow-browed Warbler breeds across Russia from the Pacific coast in the east, as far south as NE China, across Siberia and Mongolia to just west of the Ural Mountains into ‘European Russia’. The majority of the population winter in south-east Asia in the likes of Thailand, Myanmar, Nepal etc. but a trend of increasing numbers is being witnessed across Europe, North Africa, Middle East and even records into West Africa. This has certainly been the case for Northern Ireland, but why? 
There are a number of theories for the increasing presence of Yellow-browed Warblers such as: Reverse Migration (misorientation) – the birds travel in the opposite direction expected, an increased breeding population west of the Ural mountains and a shift in wintering grounds – where birds in natural dispersion have successfully wintered (e.g. in England), made the return journey to their breeding grounds and have become genetically programmed to repeat this successful route and pass it on to future generations. An exciting new project, ‘Project Yellow-browed’, a collaboration between three universities across Germany, Holland and England, aims to study the movements from Europe, into, across and onwards from Britain, of the Yellow-browed Warbler and other reverse-migrants. They will be using a range of tracking technologies, but focused on fixed radio telemetry, based on the very successful Motus system used in North America, with Motus telemetry stations located along the east & south coast of Britain, mostly at our fellow BOC Bird Observatories. The project may be further extended in the three partner countries and there is further interest across Scandinavia, Belgium, Russia and Bulgaria. 
The first three Yellow-browed Warblers to be recorded in Northern Ireland were on Copeland Bird Observatory, the first of these in 1957, followed by 1962 and 1974. Pre 2010 there had been one further CBO record and six more across Northern Ireland. From 2010 the occurrence of YBW increases substantially and a further 24 records have been accepted over the 9 years, nine of those on CBO. 
Figure 2: The distribution of records of Yellow-browed Warbler across Northern Ireland 
All but three of the 34 records have come in October with a core period of passage around the 13th October (+/- 2 days). Two of the records were on the 23rd and 25th of September in the magic Sycamore tree in Antrim Gardens, Portrush which held a YBW four years running between 2013-2016. On the 11th of March 2017, CBO recorded Northern Ireland’s first spring bird which may well have wintered further to the south (Cornwall could be a good call) and was making its way back to western Russia or further east.  
Yellow-browed Warbler Records on Copeland Bird Observatory 
1957 – One trapped & ringed on 12th October (CBO) 
1962 – One trapped & ringed on 13th October (CBO) 
1974 – One trapped & ringed on 13th October (Neville McKee, Peter Bain) 
1992  One observed & photographed on 21st October (Anthony McGeehan, Dave Allen) 
2010  One trapped & ringed on 13th October (David Galbraith, Philip Galbraith) 
2011  One trapped & ringed on 2nd October (Neville McKee, Peter McCarron) 
2014  One trapped & ringed on 4th October (Ian Humphreys, David Stirling, Peter Smyth) 
2016  One trapped & ringed on 29-30th October (Richard Donaghey, Steve Fyffe, David Stirling) 
(although not in the observatories recording zone, a YBW was sighted a few hundred metres away on Big Copeland on 10th October)  
2017  One trapped & ringed on 11th March (Chris Acheson, David Stirling, Peter Smyth) 
             One trapped & ringed on 12th October (David Galbraith, Philip Galbraith) 
             One trapped & ringed on 14th October (David Galbraith, Philip Galbraith) 
2019  One observed on 11th October (David Galbraith, Philip Galbraith) 
             One trapped & ringed on 26th October (Richard Donaghey, Ed McGuiggan) 
Figure 3: Yellow-browed Warbler (David Stirling) 
As we stand at the end of the 2019 season, Yellow-browed Warbler is now a much-anticipated vagrant (now migrant?) each autumn on CBO and more likely to be encountered than some of previous regularly encountered scarce birds such as Garden Warbler, Redstart and Ring Ouzel. With sufficient island coverage in the 20’s, it is likely that numbers will continue to rise and the 2017 record of three birds surely wont last long. The Yellow-browed Warbler is still a very desirable bird in Northern Ireland and if you’d like to find your own, there is no better place than Copeland Bird Observatory!   
Thanks to Derek Charles for providing the records of Yellow-browed Warblers for Northern Ireland.

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