Help with greylag geese ID

[Tringa]

Yesterday morning I was looking at some geese on a nearby field. Even before using the scope I was fairly sure they were all greylags.

This seemed to be confirmed when I loooked through the scope - big geese, all about the same size, body colour and pattern, pink legs and orange-yellow bills - just like I would expect them to look, except for some (probably about 8 or so out of the flock of 25-30). These were identical except they had a broad, very dark band, about half way up the bill. The lower edge of this band was a bit irregular, the upper edge a bit sharper, but the orange/yellow of the bill was easy to see both above and below this band.

Sorry I have no photos, they were about 200 yards away and I don't have any digiscoping gear.

Is this just a variation due to age or time of year that I have not seen before? The Field Guide to Birds of Britain and Europe says greylag bills have no black.

Thanks

Dave

[RoyW]

Hi Dave,

As it sounds like you are talking about the edges of the mandibles being dark I guess that one suggestion should be that the birds that showed this had been feeding somewhere, or on something, that had made the edges of there beak dirty (personally I think that this is unlikely though).

I would suggest that these birds may have had some genes from a domestic breed of greylag (something that is quite common in feral flocks). The 'Steinbacher' breed has black along the edges of the bill, which form a band like you describe, + also has a black tip (nail). They closely resemble 'wild' Greylags in plumage. (search for "Steinbacher geese" to find some images).
The genetics that produce black on the bill may also perhaps be found in your flock as a result of a natural mutation (or hybridisation with a related goose species) - in theory it has to be possible for any (or at least most) characteristics that man has selected in domestic breeds to occur naturally.

Roy.

[lastcornishman]

Hi, sorry Tringa, don,t mean to hijack your thread, but on the subject of Greylag geese, took this on saturday while walking the camel trail, i presumed this to be a Greylag, but stand to be corrected,thanks L.

[aeshna5]

Originally Posted by lastcornishman

Hi, sorry Tringa, don,t mean to hijack your thread, but on the subject of Greylag geese, took this on saturday while walking the camel trail, i presumed this to be a Greylag, but stand to be corrected,thanks L.

Very much a domestic type Greylag.

[Tringa]

Thanks for the info Roy. Re-reading my post I realise I should have been clearer. The dark bands were not along the edges of the mandibles, but across the bill.

However, your reply has made me think that crossing with domestic geese or other semi-domestic geese could be the answer; its not exactly uncommon in geese.

Thanks

Dave

[Dogghound]

Juvenile Greylags have a dark nail on the bill, possibly some young birds amongst the others. Although the banding doesnt sound normal.

[RoyW]

Originally Posted by Tringa

The dark bands were not along the edges of the mandibles, but across the bill.

In that case I haven't got a clue!