Hairy Dragonfly - Brachytron pratense

Adult size

Overall length: 54 - 63mm   Hindwing length: 34 - 37mm

Distinguishing features

This is the first hawker on the wing and is a spring/early summer species. They are small in size and quite dark in appearance. Up close have obviously very hairy thorax. A very early and short flight season means it’s likely to be under recorded and overlooked.

Identification - for help with terms see glossary

Mature males

Have small paired blue spots against a black abdomen. Antehumeral stripes are thin and yellow-green. From the side thorax is entirely green unlike other hawkers. Costa (wing edges) are yellow-brown. Thorax is hairy but only visible close up. Eyes are bright blue.

Immature males

Resemble adult males but with pale yellowish dots and antehumeral stripes. Eyes begin pale brown & go blue as they mature.

Mature females

Have small pairs of yellow dots against a brown abdomen. The antehumeral stripes are incomplete or absent. Thorax is green from the side as in the male. Has Hairy thorax like male. The eyes are brown-yellow.

Immature females

Like mature females with paler markings.

Habitat

Mainly found near well-vegetated still water bodies such as ponds, ditches, lakes but also found in slow flowing waters. Does not tolerate polluted waters.

Behaviour

Males are territorial and patrol small areas over open water. Both sexes only active during warm sunny weather and will rest if cloudy. Females are much less likely to be seen as they spend most time way from water.

Status and distribution

Has a very uneven distribution in Britain, strong in the south east but does occur in patches in north and west and is increasing its range. Seems to be rare in Dorset, with scattered sightings, but could be overlooked.


 

Flight period

Main flight period is late March to July, peaking in May & June.

Similar species

The Hairy Dragonfly can occur in habitat that supports 3 other blue Hawkers in the south: Migrant Hawker, Southern Hawker and Common Hawker. It’s very early emergence and small size usually separates it from the others. The similar sized Migrant Hawker is on the wing when the Hairy Dragonfly has finished its flight season.

More photographs

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Mature Male (photo © David Kitching)

Mature Female

Mating Pair

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