Tuesday, 6 October 2015

A possible record of Icelandic Redwing Turdus iliacus coburni in Derbyshire

Frost & Shaw document a single county record of the Icelandic race of Redwing T.i.coburni in the The Birds of Derbyshire referring to the first publication of Birds of Derbyshire by Frost. The bird was ringed at Hackenthorpe in 1972, although the location no longer falls within the Derbyshire County boundary and is now in South Yorkshire.
The first local autumn records of both Redwing and Fieldfare are awaited with anticipation and so a call from Ken Smith on the morning of 4th October to report having seen both Fieldfare and Redwing on Flash Lane, Beeley Moor with a large group of Mistle Thrush was of local interest. I was in the area so decided to see if I could see the birds.
The Mistle Thrush flock was easily located and numbered between 40-50 birds which was an interesting record in any case. Unfortunately they were very distant in tall trees about 300m from the road. I decided to wait close to one of few grassy fields in the area, a horse paddock, and gradually the flock started to move closer to feed on Rowan berries. I quickly located the associated Redwing and counted 10 to 15 birds loosely moving with the Mistle Thrush flock. 
Eventually the birds came in to the trees at the back of the paddock and started to drop down in the grass at the back of the field.I was immediately struck by how dark the Redwing were, the ear coverts and breast streaking looking almost black at the viewing distance of about 130m. I took some photos, concentrating on the nearest birds, there were perhaps half a dozen Redwing on the ground but most were partially obscured by the field falling away towards the back.
The flock were then disturbed and flew to neighbouring trees and I left them. I didn't give much thought to the race of Redwing I had observed until I got home. I had recently purchased Martin Garner's Birding Frontiers Challenge Series for Winter and recalled that Icelandic Redwing was one of the birds featured. Looking at the illustration on p77 this looked very similar to the bird I had photographed, particularly in relation to the extent and colour of the breast streaking and the way it combined to form solid lines rather than discrete streaks. I also compared the photos with my own of nominate Redwing and obtained photos of Icelandic birds taken by Ken Smith, some of which are reproduced below.
Redwing possibly of Icelandic race coburni Beeley Moor 04.10.15 © Andy Butler
Redwing possibly of Icelandic race coburni Beeley Moor 04.10.15 © Andy Butler

The views and photos were not sufficiently good enough to age the birds and it should be noted that the photos of Icelandic birds were all adults taken in June.
Redwing T.i.coburni Iceland June © Ken Smith
Redwing T.i.coburni Iceland June © Ken Smith

Redwing T.i.iliacus Derbyshire December © Andy Butler
Redwing T.i.iliacus Derbyshire December © Andy Butler
Without trapping these birds it may not be possible to claim with certainty that it is an Icelandic Redwing but it certainly showed characteristics of that race.
Of note is the fact that there had been no arrival of Redwing on the east coast prior to the occurrence of these birds. At Spurn the daily log recorded just 13 birds in the recording area on the 3rd October. Is it possible therefore that these birds arrived from the NW rather than the east as the autumn arrivals locally usually tie in with an influx in the east coast?
The purpose of this note was firstly to document the details and secondly to bring the possibility of coburni occurring in Derbyshire to other observers.

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