Saturday, 25 July 2009

Gulls on Film, Part I

Saturday 25th July. Croxden Quarry, 12pm.

Text from Andy read "Juv YLG". Ok then, I'll have a look but I will readily admit, although I'm fine with adult Yellow-Legged Gull, my experience of juveniles is absolutely zip. This was the bird in question.

It looked good to be one, certainly looked different to a nearby juvenile Lesser Black-Backed Gull, here for a comparison:

Another comparison picture being the subject in question at the bottom, compared with the darker juvenile bird in the top left-hand corner.

But what I didn't want to do was just take his word for it and tick it off. I wanted to take some photos, go away and study the bird, work out for myself what made Andy think this was a Yellow-Legged Gull and try to learn from it.

With the help of the Malling Olsen and Larsson "Gull Bible" and Alan Dean's Gulls in the West Midlands Region website, I think it's because of the following areas on the bird:

What I have worked out is a clear contrast of colour between the tertials and greater coverts, rules out juv Herring Gull. This bird also has a paler head and mantle compared with juv Lesser Black-Backed. But I'm not sure if it's just me, but the shape of both the tertial edges and the scapulars seem to be more rounded than on LBBG.

Of course, I could be talking complete twaddle, I usually do. I don't claim to know everything. If anyone happens to look at this and think I'm wrong then please do let me know, otherwise I'll never learn. It's given me a headache anyway!

1 comment:

Kay said...

Move over Klaus and Hans!