Primary school

Thursday, March 11, 2010

If you are not interested in the finer details of large gull identification, you may as well quit this post now.  Come back tomorrow, there is nothing for you here...

I arrived at the Wandle yesterday, and there were two Lesser Black-backed Gulls (LBB) on a post.  As you may know, the LBB doesn't have a black back unless it is a fuscus fuscus so the more accurate name for it should be Lesser in-the-top-half-of-the-Kodak-gray-scale-chart-backed Gull.  Anyway, it is not uncommon to find slightly different shades on the back of these gulls in this area, and I usually (and sensibly) dismiss them as individual differences, but there was a third bird yesterday that I thought was dark enough to warrant further investigation.  You never know, I might find a continental intermedius on the patch.  So I peered at it for a bit, took some photos, came to no conclusion at all and left. 

Later that day, I pulled out the big scary gull book to see if I had a graellsii or an intermedius.  It was all quite inconclusive as the shades of gray differ and there is a certain amount of interbreeding between the two subspecies.  That was until I stumbled on the killer bit of ID factness.

And there it is, plain to see.

Once you know, you know.  And I now know that the small mirror on P9 makes it an absolute certain graellsii.  Excellent, it's just a common bird.  Just like all the others on the patch.

See, I told you that you there was nothing else but gulls today.


Jonathan Lethbridge said...

As you know, I hate Gulls, and rarely feature them on my blog. However this tidbit is a gem, as that book is far too scary for me to open, so thanks.

Ernest said...

But what you should be asking yourself is... what is the PURPOSE of this tiny P9 mirror, and what is its evolutionary significance?
I bet that Gull person doesn't say anything about THAT. Pah!
Wait till the Gull molecule is discovered. The Blue Tit molecule is completely unravelled now, see mostlybirdingwithray to see what it looks like AND what it all means. best wishes from Ray

Anonymous said...

You will doubtless be aware of the sorry tale of Omissus, the beautiful gull who loved to stare at his own reflection? He omitted to breed with his congeners and was punished in two ways along with his Larid kind:-

1. binned from existence;
2. most Larids cursed to display the "mirror of vanity" forever (or until it evolved away - whichever comes first).

Don't be scared of gulls or the book - you could chuck the weighty tome at any who try to purloin some of your chips.

P.S. Due to a "toys ejected from pram episode", I have moved to if you are so inclined.

best regards

Related Posts with Thumbnails