How today's edition of The Daily Telegraph is reporting the great Yorkshire tanager twitch
THERE are lingering suspicions about the 'integrity' of this week’s Scarlet Tanager as a genuine wild vagrant that has found its way across the Atlantic to West Yorkshire.
The species is a strong flier capable of long-distance migration from as far north as southern Canada to South America.
What is more, albeit that were all at locations on the West Coast, there have been least seven other sightings reported in Britain.
But, at least to some commentators, something seems 'not quite right' about this particular bird.
Though keeping an open mind, they are cautious - not least because the Scarlet Tanager is a species of forest treetops, not private gardens.
Nor have recent weather systems in the Atlantic been sufficiently robust to have brought such a bird to an inland site within British shores.
Jon Dunn who compiles an entertaining weekly round up of recently-seen rarities for online publication Rare Bird Alert writes in his latest dispatch: "The slightly unsettling side to all of this is the location. Inland West Yorkshire not, with the greatest of respect to it, being renowned as a magnet for Nearctic vagrancy.
"Then again, we know that American passerines can and do turn up on the East Coast, so why not further inland on the eastern side of the Pennines? It’s not completely beyond the bounds of possibility, after all."
On the one hand, on the other. . .
He continues: "It is worth noting, however, that no prior Scarlet Tanager in Britain has been found away from the western seaboard.
"Scilly lays claim to four birds; Cornwall to two; and the Western Isles to one. Still, there has to be a first that breaks the mould if it’s ever going to happen.
"And, at the time of writing, there’s been no suggestion that the bird appears to be ringed, which one would assume a captive-bred example would probably be, so it deserves the benefit of the doubt."
Interpret that as you will . . .
Also active in the debate on the Yorkshire bird's provenance has been Alex Lees, senior lecturer in biodiversity at Manchester Metropolitan University.
Online, he has posted several reminders that the Scarlet Tanager is a species kept in aviaries by some dedicated aviculturists both here and in other parts of Europe - and there have been at least two past records in Britain of escapes having been detected in the wild.
(According to the Avicultural Society, the first recorded breeding in the UK was by P. Neachell in 2018.)
In his commentary, Dr Lees recalls an incident in 2017 when a White-eared Black Wheatear turned up in a suburb of Scunthorpe, causing great excitement - excitement, that is, until its owner came forward to claim it for return to his aviary.
The co-author (with another academic, James Gilroy) of Vagrancy in Birds, Lees has an enlightening section which reads: "Escapees often show 'smoking gun' features indicative of a captive past
"Many have damaged or aberrant plumage, particularly in the flight feathers and round the base of the bill where abrasion most often occurs.
"At the same time, many escapees may look and behave exactly like wild birds, and these birds can severely muddy the waters."
Although not conclusively so, some photographs of the Yorkshire bird do seem to indicate such abrasions around the base of its bill.
But Dr Lees is keeping his options open. He has not ruled out that the tanager in Yorkshire is a wild bird, noting that it bears no ring on either leg to denote ownership, nor, as yet, has anyone come forward to claim it.
"The date and behaviour is unprecedented in a UK context," he comments. "But late tanagers do show up in gardens."
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| Vagrancy in Birds is published by Bloomsbury |
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