Thursday, 1 February 2018

20180201 Coue's Arctic Redpoll Letheringsett Ford

Coue's Arctic Redpoll

Coue's Arctic Redpoll
Note pale pink wash to lower white rump panel.
As with the Crossbill group and clines the Redpolls have similar issue as to the actual number of species within their genus.
Three distinct forms are generally acknowledged, two of which, Lesser and Mealy occur during winter here on the Norfolk Coast. It was said of this species split (and armchair ticks) that it 'surprised and delighted birders in equal measure' Vinicombe 2001. They have since be re-lumped....!? much to the lumpers delight. But this has largely been sidestepped by the British birding community who do know best.... For the purposes of this article they will be re-elevated to almost full species level... Also in common with several other finches that breed at higher latitudes in the northern hemisphere and feed chiefly on seeds, they are far more conspicuous during eruption or invasion autumns and winters when they migrate much further South. They are then found on alders and weedy margins here during the winter months.
On top of this situation are the two forms of Arctic Redpoll which are even more northern, which also occur here in harsh winters, Coues's and Hornemann's Arctic Redpolls. These surely must be split to gain full species status for consistency and yet more delight, as above.
First indications of an invasion of the Northern Redpolls this winter were good when on the 28th November I found a Mealy Redpoll at Titchwell Nature Reserve, often the carrier species for rarer Arctic Redpolls. But the hoped for increase in numbers on the alders about the visitors centre has not materialised so far this January. Since then two Coues's Arctic Redpoll have been found in a flock of about ten Mealys frequenting the Cromer golf course this January.
The Glaven valley is also hosting a very interesting flock of Redpolls this winter nearby the Letheringsett Ford. Redpolls do tend to flock and associate in winter here, helpfully for comparison for the enthusiastic, or equally unhelpfully to add confusion for the faint hearted. Having attended with interest at least four Redpoll twitches so far this winter, massive leaps of faith occur and ID confusion abounds as these flocks move about. Within the Letheringsett flock are the Southern Lessers, several Scandinavian Mealy's and at least two Coues's Arctic Redpolls feeding on the alders by the river and coming down to the weedy margins of the adjacent field.
Redpoll identification is therefore rather difficult due to clines within a given form. Caution is required for instance when separating first winter Coues's Arctic Redpoll from a rather frosty Mealy Redpoll, there being some overlap in overall appearance and specific features...