Odonata Roundup

Highlights of Andover’s Odonata 2021

We entered into 2021 with an all-out attack on Covid that, as the spring got underway and summer approached, seemed to be putting the disease on the back foot. Perhaps a more normal season was to be cautiously anticipated. The weather, however, had other ideas. February, and the first two spring months of March and April, were dominated by a bitterly cold northerly wind. Spring sightings of hibernating butterflies, such as Red Admirals, Peacocks and Small Tortoiseshells, were few and far between. Encouragingly, on the very rare occasions when the temperature did rise enough to draw them out, their numbers were respectably average. A warm day on 17 April gave me a count of 15 Peacock butterflies around our local Rooksbury Lake, which is the highest count I’ve had at that time of year. On the same day Commas and Brimstones were also well represented.

The cold temperatures meant that emergences of all insects tended to be late. It also seemed to me that the emergence periods were extended, with lower numbers appearing but over a longer period of time. I found my first Grizzled Skipper on Stockbridge Down on 19 April, with the temperature a dizzy 18C. Numbers of this species remained steady but subdued right the way through May and June, with individuals still around in July. The same was true of the other early Skipper, the Dingy. Green Hairstreaks also seemed to be around for rather longer than usual.

Even though the northerly wind cleared away as we moved towards summer the sky remained overcast more often than not, with lowish temperatures, and commonly accompanied by strong and frequently gusty winds. Nevertheless, insects only get one go at this thing called life and, as they say, the show must go on. It did take until the middle of May, though. At long last, on the 14th of the month, visiting the “secret pond” not far from Andover, I found my first Damselflies, 7 Large Red and an Azure. This is a teneral to immature male Large Red:

Immature Large Red

The larger lakes here, namely Rooksbury, Charlton and Anton, took longer to get under way. I would imagine this is simply because they contain a rather larger body of water which would, of course, take that bit longer to warm up. When they did, the result was disappointing. In 2018 and 2019 the sheer number of Damselflies was staggering. Last year they dropped off a cliff, and this year was no different. My current theory on this is that there is a dance going on with parasites. Odonata fall prey to two different kinds of parasite, internal and external. The external parasites are predominately Water Mite larvae, while the internal are Gregarines. Both attack the nymph while the insect in its aquatic, juvenile form. The Water Mites attach themselves to the underside of the nymph, mainly the thorax and the forward abdominal sections, while the protozoan Gregarines set up home in the creature’s gut. Larger and territorial species of Odonata, which basically means Dragonflies, appear to be much less vulnerable to these parasites than the smaller more communal ones, meaning Damselflies.

In a parasitic cycle large numbers of the host species support an ever-increasing population of the parasite, until such a point as the number of parasites overwhelms the host species. Then the population of the host species falls, often quite dramatically. As a result of this, of course, the population of the parasite also falls, which then allows the numbers of the host species to build up again … until the cycle is repeated. It will take several years observation to conclude that is what is happening here. In the meantime, all I can say is that Damselfly numbers were very low, as they were last year.

Notably, I did not see a single Broad-bodied Chaser this year, and none of my contacts locally reported seeing them either. If anyone reading this is also an Odonata hunter in their local area I would be interested to hear of their own observations of this species.

On 12 June I had my first highlight of the year. As yet we do not have Four-spotted Chasers breeding locally. There is usually one sighted somewhere, and usually it is on Anton Lake, but this year it was the turn of my “secret pond”:

Four-spotted Chaser

This is a fresh young male. He spent an afternoon giving me some excellent opportunities with the camera and, while I have chosen this one for this piece, there is at least one more very different one that I will be putting in my 2021 Photogallery – expect this in January/February.

My next personal highlight was this young lady:

Black-tailed Skimmer, female.

This is a female Black-tailed Skimmer. There is nothing rare about Black-tailed Skimmers, they are common all the way up to above the Midlands, and this year seemed to be a good one for them around Andover. The excitement came because females of Dragonflies are not seen anywhere near as frequently as the males. This is because male behaviour is to stake out a claim to a stretch of bank or reed bed, to patrol it waiting for a female to come by, and then to romance her and hopefully mate. The females, on the other hand, are usually fertilised very soon after emergence, and then they are focussed on egg-laying. This activity takes them down into the reeds, where their wings beating against the leaves can be heard but the insect can be difficult to see … or to photograph.

Another behavioural characteristic of many Odonata is that, when freshly emerged, they will often fly some distance away from the birthing pond or lake to assume full adult colouration. Our local wood, Harewood Forest, is known for Broad-bodied Chasers, Black-tailed Skimmers and even Emperors. I found the lady pictured in a small meadow just away from Rooksbury Lake, on the 9th of July.

Another highlight, for the same reason, was this female Emperor:

Emperor, female

I found her in the same meadow on 11 August.

Golden-ringed Dragonflies also had an excellent year, also nearly all the insects I saw were male:

Golden-ringed, male

The River Anton runs into and around Rooksbury Lake and this was something of a hotspot for them. The meadow mentioned above, just off the Lake, was the place to look, and throughout late July and into September you could all but guarantee finding at least two resting on the blackberry bushes that run down the East side. This was very different to previous years when a very occasional sighting of an individual, perhaps only once or twice through the season, was more the norm.

The later Hawkers didn’t really start appearing until the end of August, mainly I think because the weather was so poor until we got into that month. Migrant Hawkers seemed especially late – please feel free to contact us and let us know what things were like in your area. While Migrant numbers were good, when they eventually got around to appearing, Southern Hawkers are not exactly an Andover speciality. I have managed to get a couple of reasonable shots of the female over the years but the only male I’d caught was at best so-so. Consequently, this was something of a target species. On the 12 August I was rewarded with one landing a few yards ahead of me, again in that same meadow already mentioned:

Southern Hawker, male

Over the next few weeks I saw a male regularly and managed to get rather better shots than this one – see the Gallery for this year when I’ve chosen the shots. I don’t know if the insects I saw were the same one or whether the species simply had a good year in 2021. Naturally, I hope it was the latter.

Of course, those of you who regularly visit this site will know that not all the excitement around Andover this year was confined to Dragonflies. Damselflies, which often front the season, might have started late but they ended up providing the most thrilling headlines. Through into June it was dullsville, but then I was sent a series of photos from a local birder by the name of Brian Cartwright. Like most birders he prefers the winter months, as the leaves have gone from the trees and the interesting migrant species are moving in. When the warmer weather arrives, and the leaves are hiding his quarry away, like many birders, he turns his attention to whatever else he can find. He regularly sends his shots through to me and I can then identify any Odonata, sometimes along with beetles and other bugs he has found. Normally, he haunts Anton Lake, but on the 23 June he had managed to escape to Stockbridge Common, and sent through a series of shots for me to peruse. Most were male and female Banded Demoiselles, which are a veritable plague up and down the local chalk streams, but tagged on the end was a mildly blurry image of a small, blue Damselfly. I recognised it immediately, not because I see them everywhere all the time but because it is one of the country’s rarest Damselflies and something of a Hampshire speciality. I wasted no time but went straight down to the Common the very next day to try and find them for myself. I was successful within a minute of starting to hunt and, in spite of a horrible wind, managed to pick up some good shots:

Southern Damselfly, male

This is a male Southern Damselfly. They are basically found on the Itchen around Winchester, on the River Test around Mottisfont, and there is a colony over in Pembrokeshire. I won’t go into details here, I wrote an article covering my adventures earlier in the year, but the next day I returned, to examine how extensive the colony was, and got several shots of females of the species:

Southern Damselfly, female

Back at the end of July 2017 I had discovered Small Red-eyed Damselflies on Charlton Lake. Anton Lake is just over half a mile away, as the crow flies, and I saw no reason why they shouldn’t be there as well. The problem was that the insect likes to perch on emergent and floating vegetation, and there was nothing anywhere near the bank of the lake. However, the wetter weather over the intervening period has raised the water level in the local lakes and encouraged growth of the horsetails and other water plants nearer to the shoreline. On top of this, this year has seen a spectacular bloom of aquatic moss over the surface of all three of our lakes, so, on 19 July, I visited Charlton Lake to see if I could find them. I counted several so, knowing that they were out, the next day I went to Anton Lake. I sat on a fishing pier at the East end of the Lake, beside what is known as the Tench Pond, and they were dancing around in front of me, with plenty of mating and egg-laying going on:

Small Red-eyed Damselfly, mating pairs

I already felt that the discovery of the large Southern Damselfly site on Stockbridge Common had made 2021 an outstanding year, but the fates had not yet finished with Andover! On 17 August Brian Cartwright, yes, that man again, took a photo of a red Darter and sent it to me. Again, as soon as I saw it, I knew exactly what it was:

Ruddy Darter, male

This is a male Ruddy Darter. Not the rarest insect in the world but, while Andover has an army of Common Darters, nobody has yet found a Ruddy Darter here, and certainly not managed to capture it on camera to provide the proof. I believe I’ve seen them at Rooksbury, one last year and one this, but without that photo it’s all just a maybe.

Brian came through again on 15th September from Anton Lake. Once more it was in a series of photos and, of course, I knew what it was as soon as I saw it:

Willow Emerald, male

This is a male Willow Emerald – note the pale stigmata towards the ends of the wings which are the diagnostic markings for this species. I have been searching for them for a while as I know they have been spreading across the country. I also believe that I got a glimpse of one at Rooksbury shortly after Brian sent me this.

Just when I thought the season was done another birder, by the name of Dave Piper, sent this through to me:

Common Emerald, male

This is a male Common Emerald Damselfly. This is not a rare Damselfly but he found it at Rooksbury Lake. They are not common at all in the Andover area, although there is a modest colony on Anton Lake, so it was excellent to find this one which suggests they may be expanding their area.

Now the season has come to a close, everything is shut down, the nights are drawing in and winter is setting its chill on us. It’s a time for going through all those photographs you took, sorting the wheat from the chaff, filing the good and binning the trash. Remembering those things you saw for the first time, identifying new places to hunt and dreaming of what you will find next year. The shortest day of the year is racing down upon us, then the days will slowly but surely grow longer. The sun will regain its warmth, the buds will burst and you will find a Peacock, resting just there, as you do every year on that first decent day … and a Tortoiseshell just over there.

When the warmth does eventually start waking everything up, get out there, get hunting. Look in places you never thought of looking before. Search all the old favourites, but try and look with new eyes. The climate is warmer than it used to be and species are moving northwards and establishing new colonies all across the country. They are there for you to find.

Until then … Merry Christmas!

John Solomon

http://www.nwhwildlife.org is the HOMEPAGE. Scroll down for 130+ ad-free articles.

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