Black Darter - Sympetrum danae
Adult sizeOverall length: 29 - 34mm Hindwing length: 22 - 27m
Distinguishing featuresBritain’s smallest dragonfly. Mature males are uniquely all black and cannot be confused with other species. Females can be trickier to separate from other darters but can be done if you know what features to look for (see detailed description below). Restricted to acidic waters such as bog, mire and heathland.
Identification - for help with terms see glossary
HabitatNeeds shallow acidic waters in which to breed and so is restricted to heathland moorland and bogs. It is really a northern species but is found on southern lowland heathland in Britain.
BehaviourThe males’ markings would seem to play a part in the insects’ thermo-regulation and alter its behaviour according to temperature (Brooks 2002). So they will perch in different place depending on conditions. Males are not territorial or very aggressive. Can be found in large numbers in habitat close to water. Females much less likely to be seen as they rest in dense vegetation away from water. Egg laying is usually in tandem as with other darters.
Status and distribution
More common in north of England, Scotland and Wales, with some sites in southern and southern England. Restricted to heathland sites in Dorset but can be abundant at suitable sites.
Flight periodMain flight period is June to October peaking in mid July to mid September.
Similar speciesMales cannot be confused with any other species. Females may confused with other darters however, especially Ruddy Darter which has similar markings. Both have a ‘T’ shape on the thorax but it’s much broader in the Black Darter. When viewed from the side it becomes very obvious. Ruddy Darters have an all yellow thorax and abdomen is all yellow. Female Black Darters have yellow and black stripes on the thorax, one of which has 3 small yellow dots. There is also a thick black stripe running down the length of the abdomen.
Click on the photos below to enlarge..
All photographs by kind permission & © of Ken Dolbear unless otherwise stated. All rights reserved.