The Emperor Dragonfly (Anax imperator) is a widespread species, particularly common in Norwich. The largest Norfolk dragonfly, this has a 10cm wingspan and is an impressive predator, particularly on other dragonflies!
The bright green thorax without any stripes, and the thick black line down the abdomen make this an easy spot. They fly with a down curved abdomen (like the migrant hawker) and are usually to be spotted patrolling the centre of ponds and rivers.
Although they will share the water with other species - since they typically patrol higher up than most species - they are agressive and will periodically chase off other species. Given their habit of making lunch out of damselflies and smaller dragonflies, these will often appear quite subdued in the presence of the "boss". Some species however, seem oblivious - banded demoiselles for example will happily continue to flutter around when an emperor is hawking above, a habit that frequently ends in lunch for the emperor. Even brown hawkers, no mean bully themselves, can get hasseled, but usually hold their own.
One of the best spots for close up views is the Vinegar Pond on Mousehold Heath in Norwich, particularly early in the morning or late evening when they can be found roosting in the surrounding gorse.Error processing SSI file