The Common Hawker dragonfly is badly named, as they are not all that common in my experience. They are usually found in moorland habitats, and this one was found near the top of Cragside (after a long climb up on foot). Hawker dragonflies tend to be identified by colour, and this one is similar in colour to the Migrant Hawker, but the coloured areas are smaller. However, the distinguishing feature of the Common Hawker is the yellow leading edge on the wings (called the 'Costa')

The one below is a female Common Hawker. On subsequent visits I have found that these dragonflies are indeed very common on the tarn (slipper lake). They can be seen sparring over the lake in good numbers.

The last two photographs show freshly emerging adults. The colours are initially very muted, but you can see two clear pale lines pin its thorax (sides) - other hawkers have more solid coloured areas. You can also see the pale costa.

In the third photo below, the adult is still in the process of emerging from its larval case - looking like something from an Alien movie! The whole process can take 3-4 hours.