Monday, 28 June 2010

Wandering Wildfowl

There is no single auditor of the ‘official’ Shetland List, it is something that has been developed by consensus over the years. Many people will remember that Dennis Coutts compiled a small checklist more than 20 years ago (it had a King Eider vignette on the cover). More recently, the authors of The Birds of Shetland, in conjunction with the local records committee, and the task of deciding what was in the main body of the book. Official national decisions were followed with one major exception, Category D species were included in the main list, in line with the policy of Shetland listers, who have always included Category D species on their lists. (For those who are unsure, Category D, which does not form part of the British List, is intended as a holding category for potential vagrants, until their true status is clearer).

Since the publication of The Birds of Shetland there have been no contentious issues, until recently. Compiling the Shetland Bird Report 2009 was trickier than usual, as a decision had to be made on what to do with two contentious species. At first, I admit, I took a hard line and was all for putting them in the appendix, but in the end I relented, partly because another contentious species turned up earlier this year. So here are some thoughts on three controversial wildfowl.

Wood Duck

The male found by Rob Fray on Loch of Brow on 16th April 2009 initially elicited some excitement (photo by Rob Fray). It was very wary and so there were hopes that it might be a candidate for Category A of the full British List. Its long stay did it no favours though, and when it was still around in early June it was being dismissed by several observers. Nevertheless, there are spring records from Iceland, so maybe it still has a chance of being wild, and while it probably doesn’t overcome the ‘credibility barrier’ it is another reminder that this species is a potential vagrant (which is what Category D is for). In The Birds of Shetland, Wood Duck was one of two species included in the main list despite not even being in Category D - it was termed a Category D candidate (the other category D candidate was Yellow-headed Blackbird, since moved to D). So, with two Category D candidates already on the Shetland List, another one is not a problem.

Ruddy Shelduck

A female found by Mick Mellor and seen briefly at Spiggie and elsewhere late on 30th April and early on 1st May 2009 was, perhaps surprisingly, the first ever seen in Shetland. Ruddy Shelduck is controversial among British birders as records are regular, but the only ones accepted as being wild are from the 19th century, and so in Category B of the British List. There are three possible origins for the Shetland bird – it could be wild, it could be from feral populations in Europe, or it could be an escape. It is difficult to say which is more likely in Shetland. Strictly speaking, to be an acceptable record this bird would need to be accepted into Category A of the British List, and this record does not have the credentials to overcome the problems that the species has in being accepted. But it is surely a potential vagrant in Shetland. Species can’t be in Category A/B and Category D in a British context, but is surely a Category D candidate in a Shetland sense.

Egyptian Goose

An Egyptian Goose was seen at various locations from 24th February 2010 (photo by Roger Riddington). Egyptian Geese breed in Africa, but there are feral populations in Europe, especially in East Anglia, so it is on Category C of the British List (for naturalised species). It is not in any category of the Scottish List, however, with all sightings believed to relate to escapes. Nevertheless, we soon had contact from regular Foula visitor Kevin Shepherd, who lives in Norfolk, who informed us that late winter and early spring was the time to see Egyptian Goose on ‘vis-mig’ past the Norfolk coast, while we also discovered that populations in Denmark and the Netherlands were larger than we thought. Bearing in mind the snowy weather at the time, surely this bird was a vagrant from a naturalised population.

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