Saturday, 28 July 2018

Rare Emeralds

Regular readers may recall that a couple of years ago on the way back from the Western Purple Swampmonster I made a detour (see here) to see the Southern Migrant Hawkers at Wat Tyler CP and that I also tried for the nearby Scarce Emerald Damselflies at Bowers Marsh RSPB but came away without a definite sighting of the latter. Accordingly I've been meaning to go to try for the ScED again but never quite got around to it last year so this year I decided to make a bit more of an effort. Since my last attempt a resident breeding colony of ScED and also Southern Migrant Hawkers has become established at Canvey Island in Essex so I decided that this month I would pay a visit. With the weather forecast not being an issue in the prevailing heatwave I was just waiting for a convenient gap in my work schedule when I stumbled across some news on the British Dragonfly Society sightings page of a colony of Southern Emerald Damselflies in Buckinghamshire of all places! Now Southern Emerald is even rarer than Scarce and to my knowledge there were no public locations where this species could be found so I was keen for more information. The BDS report was rather vague on details so I started to do some investigation and eventually got all the gen. There seems to be some ambiguity as to whether this should be public information or not: I was told in confidence so I shan't give away any more details though it won't take much effort to find out all you need to know if you explore the BDS sightings pages in a bit more detail. Anyway, I elected to pay a visit to this location first and asked PL if he'd like to come along. He was keen so it was that we rendezvous'd just east of Oxford and in light traffic we'd soon arrived at the location. In the extreme heat we walked slowly down the footpath towards the general area where I'd been told they could be seen and it wasn't long before we'd found our first one in amongst some brambles. As we moved further down the path they became more frequent and near the hot-spot by the hidden pond we met a familiar face in the form of fellow Odonata enthusiast WB. With plenty of the SoED to be found, including lots in pairs, PL and I whiled away the time taking loads of photos.

Southern Emerald Damselfly is normally to be found, as the name suggests, in the southern countries of Europe though there is an established breeding population in the Netherlands now. As the climate in this country changes species such as this are increasingly going to colonise and this is surely just the first of many such finds. In terms of identification it can easily be picked out by the bi-coloured pterostigma (the dark wing patch towards the front tip of the wing) which is unique to this species for European Damselflies and which can easily be seen in the photos.

With theses bonus rare Emeralds in the bag, a few days later an opportunity arose to pay a visit to my original target, namely the Scarce Emerald Damselflies. My VLW was due to take her turn looking after her elderly mother in Surrey so I offered to drop her off on Sunday and then to nip around on the M25 to Canvey Island for my target. I say "nip" though in the end it was anything but that. With it being the first weekend of the school summer holidays, the traffic was very heavy and around by the Dartford Crossing it was crawling along and I spent some three quarters of an hour in a stop-start queue. Finally I was across and almost immediately was turning off towards south Essex where in much lighter traffic I made good progress and a little while later I was pulling up by the famous ditch which housed the first proper UK resident breeding population of Southern Migrant Hawker and also Scarce Emerald Damselfly. 

The normally water-filled ditch turned out to be almost completely dry though this didn't seem to matter to the SMH's and a patrolling male could be found every few metres along the ditch. The ScED on the other matter were much harder and it was a while before I found one skulking in the vegetation - I think that the rather overcast conditions meant that they weren't flying very much. As I worked my way along the ditch I managed to find quite a few more though I saw no where near the 50+ numbers that had been reported on-line. Still it was nice to see them and I whiled away the time trying to get some decent photos. I did manage to find a SMH actually perched and so get a proper non-flight photo and eventually also manage some reasonable ScED shots as well. 

Scarce Emerald Damselflies

This happless Hawker has been caught by a huge Wasp Spider

A couple of perched Southern Migrant Hawkers
Contrary to its name, Scarce Emerald Damselfly is actually one of the most widely spread species in the northern hemisphere, occurring in Europe, Asia and North America. However, it's never become well established in this country and various colonisation attempts in recent years have had mixed success. In terms of identification the males are distinguished from the similar Emerald Damselfly by the fact that the blue colour is missing from the low half of the S2 segment at the top of the abdomen. Other than that you have to get to grips with the differing shapes of the anal appendages. As far as breeding is concerned, like SoED, ScED lay eggs in vegetation which remains dormant over the winter before hatching in the spring so the fact that the ditch has completely dried up shouldn't matter to them at all. For the SMH on the other hand I think that their breeding cycle may well require the constant presence of water so it's possible that this colony might die out this year which would be a terrible shame.

Sunday, 15 July 2018

Summer Orchids

I've been on a couple of Orchid trips over the last few weeks which I thought I'd write up in a single post here. The first was a brief spur of the moment trip down to Warburg NR in the south of the county specifically to see Lesser Butterfly Orchid which I'd not seen before. I'd recently learnt that this species could be found here so I got in touch with the warden there via e-mail and got back a reply telling me exactly where to go. So armed with this information I made the surprisingly long trip down to the reserve - the narrow winding lane at the end seems to go on for ever! In the warden's office there was a helpful map showing where various orchid species where to be found though I noticed that they hadn't actually marked up the LBO on it. I took a photo of the map on my phone for reference and then headed off to follow my e-mail instructions. It wasn't too long before I was looking at a couple of very much past their best LBO's.

Lesser Butterfly Orchid - note the rather delicate jizz...

...the diagnostic near-parallel pollen masses...

... and the extremely long straight spur

The open paths of the reserve were a riot of colour everywhere and I could have spent a long time rummaging through the flowers there but I was on a bit of a tight schedule so it was just a quick whistle-stop tour of the rest of the area before I headed home.

Bee Orchid

Greater Butterfly Orchid - a more robust species, with angled pollen masses and shorter spurs

Pyramidal Orchids were everywhere

My next trip was a long overdue one down to Noar Hill NR in Hants. This is a well known site for butterflies such as the Duke of Burgandy but is also a top site for various orchids, including Musk Orchid - the target of my visit. It was going to be another scorching hot day so set off reasonably early in order to try to avoid the worst of the heat. The journey down was uneventful and I was soon climbing the steep path up to the reserve. I'd been studying the location on various maps beforehand but it turned out to be a completely different layout to what I was expecting. It was all so compact with lots of mini hills and ridges one after another. 

Noar Hill
It was a riot of summer flowers of all sorts there including loads of Pyramidal Orchids, plenty of Chalk Fragrant Orchids though they'd almost all gone over and just a few Common Spotteds. Fortunately I'd been given some very detailed instructions by IE and soon found the Musk area where someone with a camera pointed them out to me. This species is similar to Fen Orchid in that it's a small light green orchid that you really have to look out for carefully though there was a nice clump of them close to the path which made it a lot easier to spot.

A clump of Musk Orchids. You get a sense of just how small they are from this photo
Musk Orchid
Having  quickly found my target I had a general wander around where I managed to find a few more individual Musks tucked away in the grass as well as lots of other lovely flowers. I had been told that there were some Frog Orchids nearby but couldn't find them.

Common Spotted Orchid

Pyramidal Orchid

A past it's best Chalk Fragrant Orchid
On the way back home I decided to stop off to have another crack at the Burnt Tip Orchids at Ladle Hill - long-term readers may recall that last year I'd gone there but had failed to find this species. A bit of a navigational cock-up meant that I drove around in circles for a bit before eventually arriving at the familiar layby where I was soon off and yomping as fast as I dared in the heat along the path towards the ancient hill fort. Once there I scoured in minute detail the grass along the southern edge of the fort where I'd been told they were to be found but after a good three quarters of an hour I'd not managed to find a single one. 

There were quite a few Chalk Fragrants but they'd almost all gone over apart from this single specimen
I called IE (my orchid guru guide for this site) up on my phone. He was down in a bog in Hants looking for Bog Orchids but he talked me through which areas they grew (close to the path that runs along the top of the fort on the fairly flat areas) and also what they looked like. Armed with this information I resolved to have one final look and walked slowly the entire length of the southern part without any success at all. Having got into the groove of looking I decided that I might as well push on further around the fort perimeter and finally right on the bend I found what I was looking for. 

Burnt Tip Orchid - small but very striking

Once I'd actually seen one and noted the deep dark purple of the tip then I knew what to look for and I soon found plenty more in that general area. The colour was darker than anything else growing there and they weren't as tiny as I'd been imagining. They were such a striking species that I starting to think that this might be my new favourite orchid species.

Flushed with success and now with my eye in I worked my way back along the original area that I'd been looking but still no luck -  I'd clearly just been in the wrong area to start with. I found one more clump of three or four a bit further around on the bend in the south east corner of the fort but that was it. By now I was tired and hot so I headed back to the car where I soon had the air conditioning cranked up to 11 to cool off as I headed back home. It had been a successful day out.