Description

Species protected under the Wildlife and Countryside Act.

The Norfolk Hawker is one of two brown hawker dragonflies found in Britain.

Males and females look similar and have a yellow triangular mark near the top of the abdomen.

 

 

 

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Where to See

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Species GroupDragonflies
Scientific NameAeshna isoceles
Status & Distribution

Listed as Endangered in the British Odonata Red List 2008.

Legally protected under the Wildlife and Countryside Act 1981.

The Norfolk Hawker was historically restricted to the Broadlands of Norfolk and north east Suffolk. Over the past couple of decades it has spread and can now also be found in other places including Kent, Cambridgeshire, the London Wetland Centre, Hertfordshire, Dorset and Devon. There have also been sightings as far north as Yorkshire and Lancashire, as well as in intervening counties.

Habitat

The optimum conditions for breeding appear to be unspoilt grazing marsh dyke systems with clean, non-saline water, rushy margins, and preferably with an abundance of water soldier as well as other aquatic plants. Other sites include well vegetated lakes and ponds, often with a reedy fringe.

Flight PeriodNorfolk Hawker
Adult Identification
  • Length: 67mm
  • Green eyes.
  • Brown body.
  • Yellow triangular mark near the top of abdomen.
  • Males: wasted abdomen
  • Females: bulkier abdomen with no waist.
Larval Information

Hawkers have a long streamlined body-shape.

38-44mm

Mask length roughly 3x the width.

Cerci are 2/3rds length of the paraprocts at the end of the abdomen.

Threats
  • Conversion of grazing marsh to arable farming.
  • Inappropriate ditch management.
  • Nutrients enrichment.
  • Pollution.
  • The impact of global climate change and fluctuations in water levels.
Management

Norfolk Hawker Management Profile

General management principles include maintaining grazing marshes, controlling saline intrusion, controlling nutrient enrichment. There are also best practice guidelines for managing inhabited sites, particularly the dyke vegetation and the surrounding terrestrial habitats.

Similar Species

Brown Hawker

  • Brown wings.
  • Blue-brown eyes.
  • Blue and yellow markings.
Case Study

Work is underway to restore habitats for this species in Norfolk.