Welcome to Dragonfly Identification Pt 2. In this article we will look at the key identification points for six of the smaller dragonfly species, the chasers, darters and skimmers. As with Pt 1 of this ID guide I’m going to concentrate on those species that are likely to be commonly encountered and reside in Norfolk. Other species within these family groups can be found here, and yet others in the wider UK, but they are either rare and/or very localised. Once again, if you know how to Identify those and know where to look for them then you don’t need this guide.
It’s worth reiterating the key identification points to look for:
- Abdomen Colours – base colour and colour of spots
- Abdomen Shape
- Wing Colour & Markings
- Thorax Markings – side stripes and shoulder stripes
- Eye Colour
Secondary points that will help are:
- Habitat
- Location
- Date
By using a combination of these you should be able to clinch any identification. Taking a picture helps enormously and enables you to look at comparable images in reference works or online to confirm the sighting.
To make your sightings count you should visit the British Dragonfly Society website and download a records form enabling you to participate in the national recording scheme. See the embedded video below for more information concerning recording dragonflies.
Norfolk records should be sent to Pam Taylor, the county recorder, at: pamtaylor@british-dragonflies.org.uk
Several dragonflies have now emerged and will be visible from now until late summer, or even early autumn. Let’s begin…
Chasers
These are chunky dragonflies with shorter, broader bodies than the hawkers we looked at in Pt 1. We’ll compare three species that have overlapping flight periods and can be found sharing the same kind of habitat:
Four-spotted Chaser. Unlike the other two chaser species, the sexes of the four-spotted are very alike. It is on the wing from late May through to August and can be found in a variety of freshwater habitats. It is widespread and common.
The Broad-bodied Chaser, as its name suggests, has a noticeably broad abdomen giving the species a very squat look. It occupies a variety of freshwater locations and will colonise newly established bodies of water very quickly. Whilst I was filling my own pond with tap water, a female appeared and began laying eggs, all before I had finished filling, had not stocked it with any plants and was still debating what kind of edging to cement in place. The eggs hatched and the following summer we were able to watch several adults emerge from their larval cases. Another common and widespread species which flies between May and July.
The Scarce Chaser is the most localised of the three species, but where it does occur it can be abundant. The Norfolk Broads holds a healthy population, especially in areas with clean, unpolluted water and dense marginal vegetation. It can be encountered flying between May and July with a distinct peak during the second half of May and June.
Four-spotted Chaser (male). Sexes are difficult to separate, but I think this image is of a newly emerged male. For comparison purposes that’s not critical. Points to note: 1) all brown thorax with no markings, 2) bold, very obvious black spots half way along and at the end of the wings, giving the species its name, 3) ‘crazed’ effect on translucent upper abdomen with a row of yellow spots along the edge, 4) extensive black tip to abdomen, and 5) brown eyes.
Broad-bodied Chaser (male). Key features: 1) broad yellow stripes on thorax, 2) clear mid-wing, i.e. no spot, 3) prominent yellow spots along side of abdomen, 4) very broad abdomen shape which is pale blue in colour without noticeable black tip, 5) large black basal patch to wing (all chasers have these, but they are particularly noticeable on this species), and 6) brown eyes.
Scarce Chaser (male). Superficially similar to BB Chaser and BT Skimmer (see below). Specific points to note are: 1) Plain, very dark brown thorax, 2) clear mid-wing, i.e. no spot, 3) No yellow spots on side of abdomen, 4) slim, pale blue abdomen with 5) obvious black tip, and 6) Blue eyes
Four-spotted Chaser (female). Very similar to male, for comparison with other females the things to note are: 1) obvious spots at mid and end point of wing, 2) bright yellow dots along the sides of the abdomen, and 3) ‘crazed’ translucent abdomen which is plain brown in colour and has an extensive black tip.
Broad-bodied Chaser (female). same differentiators (thorax stripes, base marking of wings) as male. Specific comparison points with other female chasers are: 1) clear mid point of wing, 2) conspicuous yellow spots along side of abdomen that are larger than the four-spotted, and 3) very broad, plain brown abdomen with no black tip or obvious markings.
Scarce Chaser (female). Quite distinctive. Specific points of comparison: 1) dark smudges at wing tips, 2) Bold black markings along whole central length of abdomen, and 3) slim, rich brown abdomen with no yellow spots along its edge.
Skimmers
The single representative we’re going to feature is the Black-tailed Skimmer. This species is very common and will frequently be encountered basking or holding territory on paths, boardwalks and other open, sun-kissed areas. It shares many similar features to the chasers, especially the scarce chaser with which it could very easily be confused. It is on the wing from May through to August with the majority on the wing during June and July. It can be found at a variety of wetland sites with exposed bare areas nearby.
Male. As you can see the male is very similar to the male scarce chaser. Key ID points are: 1) Light brown thorax, 2) No black patch at base of wing, 3) obvious extensive black tip to abdomen, 4) faint yellow crescent marks on side of abdomen – quite often absent altogether, 5) powder blue evenly tapered abdomen, and 6) greenish/blue eyes.
Female. Quite distinctive. Key features: 1) Clear base to wings, 2) yellow/brown abdomen with two dark lines along full length of sides, and 3) olive green eyes.
Male in typical pose resting on bare ground. As you approach it will fly off a few yards further along and keep doing this until it flies back to its original spot. Note the absence of orange abdominal spots on this individual.
Darters
Darters are small dragonflies that will fiercely defend territory, returning to the same prominent perch time after time. We will look at two species which although superficially similar can, with practice, be easily told apart. The Common Darter is, as its name implies, a very common species and one which can be seen in large numbers in many different habitats, sometimes well away from water. It has an extended flight season which runs from June well into the autumn. I’ve seen what can only be described as a swarm of these insects basking in the sheltered lee of a wood in mid-November. The Ruddy Darter is nowhere as abundant as the common darter but is nonetheless a widespread and increasing species. Look for it during late summer – July to mid-September – in any unpolluted waterway, even acidic and brackish habitats.
Common Darter (male). Key points: 1) Bright yellow patches on side of thorax separated by dull red patch, 2) bright red abdomen slightly pinched at ‘waist’, 3) yellow line down legs, and 4) eyes brown on top, green below with green ‘face’.
Ruddy Darter (male). Key points: 1) brick red patches on thorax, 2) abdomen deep blood red and noticeably pinched ‘waist’, 3) clubbed end to abdomen, 4) all black legs, and 5) deep red eye and ‘face’
Common Darter (female). Key points: 1) Yellow patches on side of thorax with small middle patch surrounded by black border, 2) yellow ochre abdomen with separated black markings, 3) yellow stripe on legs and 4) eyes brown above, green below.
Ruddy Darter (female). Very similar to female common darter. Key points: 1) Side markings on thorax not separated by black border, 2) abdomen yellow ochre with larger separated black markings, 3) black legs, and 4) eyes brown above, more yellow below (not easy to see).
Another image of a female Ruddy Darter showing 1) a T shaped marking at the top of the thorax (not present on southern populations of common darter) and 2) completely black legs.
Mating Common Darters showing male red/yellow colouration well
Mating Ruddy Darters showing male blood red colouration and several features of both sexes discussed above.
I hope you find this guide useful, any feedback is most welcome. Other ID guides can be found here.
References:
Britain’s Dragonflies (Smallshire/Swash) –Wildguides ISBN 978-0-691-18141-7
Dragonflies of Norfolk – Norfolk & Norwich Naturalists’ Society – Dr Pam Taylor
All images copyright the author except:
Black-tailed Skimmer (male) , Ruddy Darter (female) – Liz Dack
British Dragonfly Society – Recording Scheme. This video is included courtesy of talk:wildlife
I hope this all helps and isn’t too confusing. Let me know what you think. For other wildlife ID guides click here
Nice one Barry.
Cheers mate