Birdwatch: Great skua

The bird came out of the sun like a second world war bomber, lumbering towards me before swerving off at the very last moment, leaving me breathless and shaken. That'll teach me for getting too near its nest, I thought. For somewhere in the marshy ground alongside the boardwalk there was a small, fluffy chick, in need of protection from intruders.

Great skuas are impressive birds. With their dark brown plumage and broad wings they look rather like a cross between a buzzard and a gull, with twice as much aggression as either. They are also one of the rarest birds, globally speaking, that you will ever see in Britain. For well over half the world population - roughly 10,000 pairs - breeds in Scotland, most on Shetland, where they are known by the Old Norse name of "bonxie".