Gulls and crows

I'm currently very interested in crows and the relationship between Carrion and Hoodie here on Orkney. Tipped off that there are some interesting hybrids at Scapa, and the weather being fine, I headed off there this morning. I spent a couple of hours photographing interesting beasts, of which the below is one.

It would be easy to pass this bird off as a pure Hooded Crow, but look at the undertail coverts. Hoodie should not have those black feathers. Also a careful look at the back and mantle shows thin black centres to many feathers. I need to check this feature out a bit but I don't think pure Hoodie should have black centres to the mantle and back feathers. Actually they do and this is an ok feature for Hoodie, the centres should be of a very fine dark streak (I could do with a corpse really to look at this properly).

I had some jobs to do in Kirkwall, and then as I was leaving noticed a large number of gulls on the PDC. There were a couple of interesting ones. I think this, left hand bird below, looks very interesting. A candidate for American Herring Gull maybe. (That would be a species I've not seen). Looking at the papers this bird certainly has some characters. It didn't fly unfortunately and I was short of time, surely worth another look though.