Saturday, 4 January 2014

British Birds vs Birding World

In the last issue of Birding World, the editors slipped in an easy to miss notice saying that the next issue would be the last of the magazine. The only reason given being that the team had a desire to move on to the next chapter in their lives which I think means retirement. Although the frequency of quality ID articles had declined in recent years I still looked forward to receiving it each month and it was the only journal I subscribed to. I had been a British Birds subscriber in my youth (before Birding World appeared) but as a poor student I couldn’t justify spending precious beer money on two journals so chose to drop BB once I had discovered BW. BW had far more interesting articles than the far more serious and scientific BB.

With BW disappearing and me soon to be journal less I therefore asked for a BB subscription as an xmas present and had it back dated such that I received the November and Decembers issues. Both issues contained a heavy weight ID/status article but the rest of the magazine still reminds me of the magazine I chose to drop over 20 years ago and contains little of interest. I hope that they quickly decide to include some of the best bits of BW otherwise it looks like I’ll have to look at Dutch Birding for my inspiration (maybe I should be doing so already).

The Subalpine Warbler taxonomy article by Lars Svensson in the November issue is a must read but is quite hard going and nothing like as enjoyable as hearing him present on the same topic back in Falsterbo. The Redpolls article in the December issue was very interesting but did leave as many questions unanswered as it managed to address. In the same issue there was also a note on the ID of two Arctic Redpolls trapped on Fair Isle in the summer months. Upon reading this note and after having read the main Redpoll article I thought that certain identification of the two Fair Isle birds as Arctic Redpolls rather than Iceland birds was unsafe therefore rendering the note superfluous. Feeling in a constructive frame of mind I put my thoughts into words and penned my own note to BB.

my own picture of an Arctic Redpoll (exilipes) from Finnmark, June 2014
I have received a very thorough reply from Roger Riddington, the Editor of BB, explaining that both birds from Fair Isle had been accepted by the relevant rarities committees (a fact that should have been mentioned in the note) and he also came with very good feedback to my comments but with the conclusion, from his side, that he did not think there was enough in my note to open up the debate in BB. I think that’s a shame as I still think there is uncertainty regarding these birds ID but will keep my powder dry for another occasion.

My note:

I read with interest the Redpolls article (British Birds 106: 708-736) and with slight surprise the note on summer plumaged Arctic Redpolls from Fair Isle in the same edition (British Birds 106: 746-748).

From the pictures and measurements presented for the two Fair Isle birds I cannot agree with the author that (Pale) Icelandic Common Redpoll can be eliminated.  Of the eight measurements given seven are within the limits given by Stoddart on page 716 for Icelandic Common Redpoll with the one aberrant measurement being tail length of the larger bird which at 69mm exceeds the range of 52-66 mm (n = 29) given for Icelandic.
Conversely the bill measurement of the larger bird at 8.5mm falls below the range given of 8.6-10 mm (n=40) for hornemanni. Therefore the measurements are, in my opinion, non conclusive and especially so given the small sample sizes.

The purpose of the note is to highlight the unexpected plumage of these summer plumaged birds when compared to autumn and winter plumage which is the expected plumage in a British context. The plumage is indeed unusual for Arctic Redpolls of the subspecies exilipes based on my (limited) experience of summer birds from Northern Norway. I would expect an exilipes to have a greyer mantle than the bird pictured.

From the current evidence as presented by Stoddart it is also not clear to me that the plumage including undertail coverts and extent of white on the rump can be used to exclude Icelandic. Additionally I note that the birds have not been aged or sexed and even though I understand this is difficult even in the hand it is surely a key factor when coming to a correct conclusion regarding plumage and (sub)species identity.

Given the uncertainties of Redpoll taxonomy and identification I would say it is unwise to state the two birds are Arctic Redpolls and to then draw conclusions on summer plumage based on this.

Simon Rix

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