Black-headed Gulls and signs of spring

A quick trip to the nearest duck pond today, in lieu of 'real birding', gave me fifteen minutes to look at Black-headed Gulls. In particular, I was looking at the pattern on the trailing edges of their wings, having noted this bird a few days ago that had a distinct step in the black trailing edge. This bird was very distinctive in flight and I wanted to see whether this was a common variant.

There were about 140 Black-headed Gulls at Blackford Pond, Edinburgh, today but I couldn't find one with quite as distinct a step in the black trailing edge, though there does appear to be variation in this characteristic.

I did notice a couple of birds with hoods now showing quite distinctly. The hood, which is a characteristic of summer/breeding/alternate plumage develops as a result of wear to the pale tips of the head feathers. These pictures show the range of head colouration in the birds today, from almost completely hooded to almost completely white-headed.

Another sign of spring noted today were the Snowdrops coming into flower in Craigmillar Castle grounds. I think that Mary, Queen of Scots, probably missed seeing these flowers by moving away from the castle in December 445 years ago, although she probably had other things on her mind...