White-legged Damselfly Investigation

Photo by Christophe Brochard

Project Overview

The White-legged Damselfly (Platycnemis pennipes) is a delicate little insect that can be found fluttering along lushly vegetated margins of rivers, streams, pools and lakes in southern England and Wales. At first glance they can be mistaken for other, more common, species of blue Damselflies, such as Azure Damselflies; as a result, it is likely that White-legged Damselfly are under-recorded. However, on closer inspection the species can be easily be identified by a number of features, the most prominent being its pale legs, which are broad and feathery in males.

In recent years there have been increasing concerns that this elegant species is disappearing from some parts of the UK, with Country Dragonfly Recorders reporting population collapse along a number of river systems. However, our understanding of White-legged Damselfly population trends it limited by a lack of long term data. Thus, in order to better understand these observations, the British Dragonfly Society has launched the White-legged Damselfly Investigation.

Project Aim

  • Train volunteer recorders to identify and monitor White-legged Damselfly.
  • Encourage the recording of White-legged Damselflies in under-recorded areas.
  • Establish the distribution and population trends of White-legged Damselfly through long term monitoring.
  • Use collated datasets to assess the need for conservation action, regarding White-legged Damselfly and their habitat

 

Become a Featherleg Finder!

We're asking members of the public to look of for White-legged Damselfly between May and August this year.

Enter your sightings straight on to iRecord here.

Remember you will also need to report:

  • Your name
  • The date you saw it
  • The name and 4 figure grid reference of where the species (you can select the grid reference from the map on irecord or find it using the Grid Reference Finder website)
  • Habitat type e.g. river
  • Optional: Photo (this can help us verify your sighting).

You don’t need to include the number you saw or breeding behaviour.

If you would like to part in the White-legged Damselfly Investigation, but don't have time to carry out full surveys, become a casual recorder using the resources below:

       

Recording guide                                       Casual Recording Form                  Simple Identification Guide

 

Take part in White-legged Damselfly Surveys!

 

We are also looking for volunteers to take part in White-legged Damselfly surveys. Volunteers will be asked to carry out surveys between May and August. The survey will involve counting the number of adult flying White-legged Damselfly at a wetland, and noting any breeding behaviour.

To get involved please contact Eleanor Colver (Project Coordinator): email:conservation@british-dragonflies.org.uk tel:07792 231 925

Resources:

                                

Comprehensive Guide to ID and recording                 Simple ID guide for the field             Site visit survey form                                   Survey form examples

Recording White-legged Damselflies as part of another Dragonfly suvery?

Please note that any White-legged Damselfly sightings recorded during other BDS surveys e.g. Dragonfly Spot, and during ad hoc recording will all feed into our project. Report and enter your findings as you normally would.

Clubtail Count: If you are going to look for, and record White-legged Damselfly at a site you have adoped for the Clubtail Count, please let the White-legged Damselfly Project Coordinator know. Follow the data recording reporting method as stated in the Clubtail Count.

Complete lists at adopted sites: If you have adopted a site that you regularly visit during the White-legged Damselfly flight season, performing complete lists, please inform our Project Coordinator. Let her know whether you will record simple Complete Lists (lists of species present) or if you peform counts (number of each species present) and record breeding information.

More information will be made available shortly.

 

All you need to know about White-legged Damselflies

 

Identification

Full length: 35-37mm

 Male: Pale blue coloration.

 Female: Cream coloration.

Photos by: David Mitchell (top), David Kitching (bottom).

This species can be found in flight from late May to mid August (sometimes be earlier or later depending on the weather). This species can be easily be identified by its bouncy flight, and sometimes it’s conspicuous white legs can be seen dangling beneath it whilst its flying.

As you can see in the photos above White-legged Damselflies are quite pale in coloration, which makes them stand out. Males are pale blue, with blue eyes, and have very wide, pale, legs. Females, on the otherhand, are more a creamy coloured, and have pale eyes as well.

Watch identification video here

 

Below are photos of some of the more common species of black and blue damselflies: Common Blue Damselflies and Azure Damselflies. As you can see they have a lot more black markings on the abdomen, so can be easily told apart from White-legged Damselflies. However, if you're still a bit unsure look at the coloured spots (pterostigma) at the ends of the wings. White-legged Damselflies have pale brown spots, while the other species have dark spots.

 

Common Blue Damselfly (Enallagma cyathigerum)

Male                                                                                                                         Female

Photos by David Kitching

 

Azure Damselfly (Coenagrion puella)

Male                                                                                                                         Female

Photo by Val Perrin (left) and David Kitching (right)

 

Habitat

You're likely to encounter breeding White-legged Damselflies along  slow-flowing rivers, canals and streams, but will also breed in still waterbodies, such as lakes and ponds. They favour unshaded waterbodies and watercourses, with abundant emergent and floating vegetation at the margins (such as water lilies and bur reeds). However, you may also find you adults (tenerals) hunting in lush grasslands or meadows adjacent to such breeding sites.

Threats

Habitat disturbance, such as extensive dredging, or intense clearance of bankside and aquatic vegetation, has been associated with population decline. This species is also susceptible to pollution, as it requires a relatively high water quality.

Distribution

While White-legged Damselfly have quite a broad distribution in the South of England, reaching into east Wales, it is relatively uncommon within its range, although it can be found at high density in localised areas.

Source: Atlas of Dragonflies in Britain and Ireland (Cham et al, 2014)

 

Other Resources

Poster