Welcome to my blog

This is where I post various musings about wildlife and ecology, observations of interesting species (often invertebrates)
and bits of research that grab my attention. As well as blogging, I undertake professional ecological & wildlife surveys
covering invertebrates, plants, birds, reptiles, amphibians and some mammals, plus habitat assessment and management
. I don't work on planning applications/for developers. The pages on the right will tell you more about my work,
main interests and key projects, and you can follow my academic work here.

Monday 20 August 2012

Focusing on the familiar V: dragonflies part I

A few months ago, a reader suggested I took an occasional look at some more familiar species. As my chosen remit is to popularise and familiarise less well-known species, I mused for a bit and then thought 'OK, why not?' which led to a short series on ladybirds. Now I have a garden pond, created and filled just a few weeks ago, and already interesting species are starting to appear, something I've been nattering about on facebook quite a bit. So, it seemed a good time to have a close look at one species in a generally popular group - the dragonflies - in particular the Common Darter Sympetrum striolatum. In Britain, this is probably the most commonly seen smallish red dragonfly (not to be confused with damselflies which are much more spindly), and is one of a number of species in a genus known in North America as 'meadowhawks'.

Male common darter Sympetrum striolatum on water mint.
First of all, its range is huge - from Ireland, Iberia and parts of North Africa eastwards through Europe as far as Japan, with migrations seen which can be huge in number. Like other Sympetrum, only mature males are red and it is these which I will focus on here. Females and immature males are yellowish as is typical for this genus.

The abdomen is almost parallel-sided (just a weak constriction in the front half) unlike others such as the ruddy darter S. sanguineum which has a more distinctively 'club-like' appearance. The abdomen is an orangey rather than deep red, while the sides of the thorax also have clearly yellowish patches (visible in the photo below).

Male common darter Sympetrum striolatum on Buddleia davidii.
As dragonflies can be variable in terms of depth of colour and other abdominal features, it is sometimes necessary to look more closely at the head to separate species in this genus. In S. striolatum, there is a black area above the 'face' running between the eyes, but this does not extend down the inside edge of the eyes (as shown in the photo below), unlike in, for example, S. sanguineum and S. vulgatum (which although common in continental Europe, is only found in southern Britain as a scarce vagrant).

Head of male common darter Sympetrum sanguineum showing limited extent of black facial mark.
So, if you are in Britain and see a red dragonfly of this shape and colour, there's a good chance it will be a male S. striolatum, but do take care as there are other options, and more so if you are on the continent. If you would like to find out more about this and other British and European dragonfly species, I've included a reading list at the bottom of this page - and if you'd like more info about creating a wildlife-friendly garden pond, why not download an advice booklet here (from the excellent Pond Conservation). Enjoy!

Male common darter Sympetrum striolatum surveying our new pond from his perch on water mint

No comments:

Post a Comment