Dragonfly in Speyside - ID needed (1 Viewer)

[DaveB]

Whilst walking round Loch an Eilien on 27th August, I came across this species of Dragonfly.

Could anyone help with the id please?

Thanks,

DaveB

 

[aeshna5]

Looks like a female Black-tailed Skimmer. These have only recently colonised parts of Scotland, say will be worth sending this record to local Odonata recorder- possibly new for that area?

 

[Ashton.P]

Hi Dave,

Looks like a female Highland Darter. I saw a few in Scotland whilst there in July. Some photos I took whilst there can be found at the following link:-
http://dragonflies.fotopic.net/c1333508.html

 

[Adey Baker]

Hi Dave,

Looks like a female Highland Darter. I saw a few in Scotland whilst there in July. Some photos I took whilst there can be found at the following link:-
http://dragonflies.fotopic.net/c1333508.html

Some good photos, there, Paul. They show how distinctive this species can be from Common Darter

 

[Ashton.P]

Hi Adey,

They are very distinctive from Common Darter, more easily over looked as Black Darter.

 

[DaveB]

Thanks for the replies

All three species that have been mentioned look good possibilities.

The markings appear to poit towards Black-tailed Skimmer, but the location suggests it is one of the other two, Black or Highland Darter?

Thanks DaveB

 

[Binocularface]

Thanks for the replies

All three species that have been mentioned look good possibilities.

The markings appear to poit towards Black-tailed Skimmer, but the location suggests it is one of the other two, Black or Highland Darter?

Thanks DaveB

Hi Dave,

Your insect is very interesting. Firstly I am not an expert! However I think the angle of the image makes the abdomen look broader than it actually is, so I can understand why Black-tailed Skimmer may have been suggested. However IMHA the relatively extensive yellow at the wing bases, colour of the pterostigma, leg colouration and apparent structure rules out this species. I also think that the leg colouration, colour of the pterostigma and apparent structure rules out Black Darter. I would tend to agree with Paul as most features appear to point towards Highland Darter. It would be interesting if you have any more pics of the insect.

Regards
Tristan

 

[Steve Dudley]

Hi Dave

Your insect IS a female Black-tailed Skimmer. Both the abdomen and the hind-wings are too broad for any darter species.

The main feature to look at it are the longitundinal thick black stripes along the upper edge of the sides of the abdomen. Each stripes is like a shallow cresent and connects to thin black bands along the segment joints. Highland Darter (and the other darters) lacks these markings and have much narrower, plainer marked upper surface to the abdomen with clear little 'blunt dagger' marks on the top of segs 8 and 9.

I've not been dragonflying for a couple of years in Speyside (but went up there annually for about 10 years up to 2004) and I have never seen Black-tailed Skimmer in Speyside so they must be very recent colonists.

Cheers, Steve
Watching British Dragonflies - see it at Birdfair 2007 - www.wildlifebooks.com

 

[Ashton.P]

Hi Dave
The main feature to look at it are the longitundinal thick black stripes along the upper edge of the sides of the abdomen. Each stripes is like a shallow cresent and connects to thin black bands along the segment joints. Highland Darter (and the other darters) lacks these markings and have much narrower, plainer marked upper surface to the abdomen with clear little 'blunt dagger' marks on the top of segs 8 and 9.

Hi Steve,

I disagree with this identification for the following reasons.
On Black-tailed Skimmer these cresents should be complete on each segement, which they clearly are not on the photo. I have viewed many photos on the net and could not find any where the cresents are incomplete. The cresents in the photo show that they join the black underside of the abdomen on the lower segements, this would not be the case on the skimmer.
Along the mid dorsal spin there are pairs of black spots, absent in skimmer.
Legs - the femur appears black in the photo, on skimmer this would be the palest area of the leg. The tibia in the photo is clearly paler than the femur, this would be the opposite way round in skimmer.
Pterostigma is obviously brown, would expect skimmer to be black.
The illustrations in both Brooks and Lewington, and Dijkstra and Lewington don't do justice to Highland Darter. The photos however in Smallshire and Swash are much more useful. The abdomen also doesn't look flat enough. Thickness of abdomen can vary a great deal depending on how well fed the individual is and also its maturity. I would say that the female in the photo is becoming over mature, therefore the markings are darker, and the abdomen thicker than one would expect, but still not broad or flat enough for skimmer.

 

[Steve Dudley]

Hi Paul

You're absolutely right, and serves me right for opening my big gob and posting based on a very quick scan of the image over a cuppa this morning.

I have never seen a female Highland Darter with quite such extensive cresent-like markings before and agree that this is an aging female which is further supported by the reddening of the central spine at the top of the abdomen (segs 1-3). Although I've visited the Highlands for many years, this was always end June - mid July when the species is first on the wing and so I have never seen them this late in the season or a female as old or as well marked as this one (my excuse anyway!). Even the pairs of spots you mention aren't actually pairs of spots any more, but more like small moustaches not unlike a skimmer (I've just looked at several images I have HD from early July and they spots are still clearly spots and not little dahes).

A couple more pro-Highland Darter features now I have studied the photo more carefully are the yellow suffused base to both fore- and hind-wings, the pale antehumeral (shoulder) stripes and when you look really closely, the radial supplemental vein has only a single row of cells (double in skimmers)!

Thanks Paul, I've learned something new today!

Cheers, Steve
Watching British Dragonflies - see it at Birdfair 2007 - www.wildlifebooks.com

 

[Ashton.P]

Hi Steve,

The photo is at a tricky angle. I only looked deeper because I was trying to understand why it was a Black-tailed Skimmer. The trouble with field guides is there isn't enough of them, and it's difficult to show all the different stages of maturity. I constantly refer to all the ones I have, shortly to be joined by yours, as they all have something different to offer.

 

[DaveB]

I got it down to the three species that have been argued, but have to admit that there is no way I could have confidently identified this female Highland Darter without the help you have provided. Learn't something as well

Many thanks,

DaveB