Common Hawker - Aeshna juncea

Adult size

Overall length: 65 - 80mm   Hindwing length: 40 - 47mm

Distinguishing features

A large, fast flying and dark looking hawker, having a very bright yellow leading edge to their wings (costa). They are more common in northern and western Britain. They rarely settle and can be difficult to approach, for this reason they may be under recorded. Very uncommon in Dorset.

Identification - for help with terms see glossary

Mature males

Have paired blue dots against black abdominal segments which give them quite a dark appearance. They have complete but thin yellow antehumeral stripes. The eyes are blue and face is yellow. A good diagnostic feature if observed closely is the bright yellow costa, or leading edge of the wing. Other blue hawkers do not have this feature.

Mature females

Have typically pairs of yellow dots against brown abdominal segments, but the dots can be green and rarely blue. The antehumeral stripes are incomplete or absent. Again the characteristic yellow edge (costa) to the wings is diagnostic. The eyes are green/brown.

Habitat

Will breed in a wide variety of still waters preferring acidic and neutral waters. Common in upland bogs, moorland and heath. Associated with heath in Dorset but in low numbers.

Behaviour

Males are very active and can spend a long time on the wing rarely perching. Males and females often fly high into the tree canopies to hunt. Can be active in overcast conditions and into dusk.

Status and distribution

Common and widespread across northern and western Britain, mainly absent from east and south of the UK. Seems to be rare in Dorset, scattered sightings, but could be overlooked.


 

Flight period

Main flight period is late June to October, peaking in July and July.

Similar species

The Common Hawker can occur in habitat that supports 3 other blue Hawkers in the south: Migrant Hawker, Southern Hawker and Hairy Dragonfly. The yellow costa is good diagnostic feature and thin or reduced antehumeral stripes. Care should be taken separating female Common Hawker with Southern Hawker. The latter has thick green antehumeral stripes.

More photographs

Click on the photos below to enlarge...

CLICK ON PHOTOS BELOW TO ENLARGE

Mature Male (photo © David Kitching)

Mature Female (photo © David Kitching)

Mature Male in Flight (photo © David Kitching)

All photographs by kind permission & © of Ken Dolbear unless otherwise stated. All rights reserved.