Wednesday 2 August 2023

Brown Argus Explosion.

 Just over a week ago I did a walk around the far end of my patch to see how the downland bank was doing, following several months of pony grazing. To be honest it was a bit disappointing as there was very little foliage left for the wildlife. However, I have been assured that the heavy grazing will eventually pay dividends, so I live in hope.

After leaving that area though I walked along the large area that has been left all year to nature, and this year has been a totally fabulous season here. With the Marjoram now in flower along with Small and Field Scabious and Knapweeds the area is buzzing with life. The biggest winners seem to be Brown Argus which have had a population explosion. I have never seen so many Brown Argus in one smallish area, roughly 150 metres long and 15 metres wide, I estimated that there was probably 1000 plus Brown Argus. That too was only one small end of the whole meadow, so many more would have been in the rest of the area.

It was such a sight that I then went back several more times, and each time was as impressive as the first time. I actually forgot to take any photos until Lisa and I went to see them a few days later. It was difficult to find any roosting in the cloudy and windy conditions that were not blowing around amongst all the tall grasses. I also only wanted perfect specimens if at all possible and no tall grass in the background. Of course, with these stipulations I only found 3 possible contenders. I did have to be extremely careful not to disturb them too as although it was cloudy and windy it was warm enough for them to still be semi active. However, the 3 different ones did produce some pleasing photos.

Brown Argus on Plantain.

Brown Argus on Agrimony.

Brown Argus on grass-head.

Nearby there were yet more smaller numbers of Brown Argus, one of which very much seemed to like the 'Pride of Sussex', the beautiful Round-headed Rampion. Several times it flew off, but each time it returned to the same flower.

Brown Argus on Round-headed Rampion.

Since those visits I have been back another 3 times. The first of which I decided I really should try to get a count of them. As I couldn't really enter the whole area without causing large areas to be flattened I walked the length of the site of approx. 150metres and counted 185 either roosting or flying and then multiplying that by 5, which was roughly how many times across the area that I could see reasonably well from the edge. I know it's far from scientific, but it's better than just grabbing a number out of the air. However, as there were many roosting that I would have missed along the length, I do think it's fair to say that the colony is over 1000.

I did take my Naturetrek group along to see them as well as a large group from the Seaford Natural History Society that I led, and everyone was very impressed by the sight of them, especially when the sun came out briefly and 100s took flight.

Other delights in the area that I saw included a family of baby Common Lizards along with their Mum. The babies were delightful when viewed up close, looking as though they were made of brass.

Baby Common Lizard.

I also spotted a female Gatekeeper that looked very striking. It was a little later when I was viewing the photos that I spotted it had an extra large wing eye-spot, and memories came back of a similar specimen that Nigel and I came across near Pevensey a few years ago that was an aberrant form anticrasipuncta. I sent an image to the county recorder and he confirmed that this one too was also the same aberrant form.

Female Gatekeeper ab. anticrasipuncta.

Lisa was really keen to see an Essex Skipper this year as she had only seen one definite one so far, unfortunately, despite quite a search for one I only found one when she was busy photographing mating Gatekeepers. By the time she had finished the skipper had flown. A couple of days later I found this one below in the same area, but of course, Lisa was not there that day. Thankfully, I did find one for her several days later when we were looking again for Grayling.

Essex Skipper showing off its mascara applicators.

1 comment:

  1. Hi Bob. Really interesting to read about the Brown Argus. Here we have the Northern Brown Argus, which live in small colonies and only produce one generation a year, in June and July. This year wasn't brilliant for them because of the cloudy and showery weather we have had. Even when I have been abroad I haven't seen Brown Argus in big numbers. Funny, but we also don't have Gatekeepers or Essex Skippers up here (yet!). We do have plenty of Common Lizards though!