Sunday, 27 July 2014

Warren Heath

As it's mid July we are still very much in the summer insect season so when I started contemplating a bijou tripette somewhere I found my thoughts turning to dragonflies. As I'm rather new to Odonata there are a number of species that I've yet to see so I thought that I'd try Warren Heath in north Hampshire which was supposed to be one of the top sites in the country. Consisting of two reservoir pools, a stream and some heath pools, it was an acid based ecology and so attractive to many specialist species that one wouldn't find in Oxon. According to the excellent Hampshire Dragonflies web-site there were a total of 22 different species of dragonfly and damselfly that could be seen. All very appealing so I made plans to head down there on Friday morning and spent the evening before doing my background research.

Friday dawned rather cool and cloudy as it had over the last few days but I knew that this would soon burn off once it started to warm up so it was with an optimistic frame of mind that I set off at around 9am from Chateau Gnome, arriving about an hour later on site. The first problem was where to park as there was no where obvious. In the end I tucked the Gnome mobile off the road hard up against the undergrowth and got my gear together.

One of the great charms of this site is how wild and untamed it is with only a few forestry tracks and no footpaths at all. It needs a good head for direction or map reading so I'd taken a snap shot on my phone of the relevant part of the OS map and which I consulted carefully as I started out. It was great to be out in heathland habitat once more with Bell Heather and Harebells lining the track as I set off. Almost immediately I came across my first dragonfly, a female Keeled Skimmer which seem to have strayed away from any pools that I could see.

Bell Heather
Female Keeled Skimmer
I walked along, enjoying the relative coolness of the shady path, listing to the high-pitched calls of Coal Tits in amongst the pines and within about ten minutes I arrived at the reservoir pools. There was no one else there at all and it was peaceful and quiet. In fact apart from a couple of dog walkers I'd not seen anyone else on my journey here at all. The western pool was a lovely bit of water running west to east, tree-lined and shady along the southern shore with a more open and sunny aspect along the northern shore. The water was dark brown and peaty and was covered in several large patches of White Water-Lily as well as being home to pond weed of various types. The eastern pool by contrast was completely devoid of water plants, more tree-lined on both sides and generally far less appealing. I therefore chose to start off on the western pool.

I'd only gone a few yards when in the first shady corner I came across one of my target species for today, namely an Emerald Dragonfly. However, as both Downy and Brilliant Emeralds were known to frequent the site which one was it? The trouble was that it was so shady and dark where I was that it was impossible to make out the relative brightness and shininess of it as it flew about. For readers who aren't aware of the subtle differences between the two species, Downy are a duller green colour whereas Brilliants, as their name suggests are a brighter green colour. The males both have a waisted look with a bulge on their abdomen though with Downy it ends with a club-like tail whereas for Brilliant the bulge is more half way along the abodment. There are other subtle differences which are best discerned in the hand or at least on a stationary insect but this one was constantly on the move hunting away low down along the shore. There were supposed to be differences in jizz as well, with Brilliant generally flying further out and higher up but given where it was hunting it was difficult to tell. In the end I decided to try to take some video footage of it as it darted about and managed to get a single grab from it where it appears in the bottom left hand corner of the video for a matter of moments. However, it was going to have to wait until I got home though before I could analyse it.

Back home and after consulting the resident county experts it was decided that 
this was a Brilliant Emerald, with the more central abdomen bulge, the yellowish 
tinge to the wings and the brighter colouring being the main pointers as well as
reports from previous recent visitors to the site of what was located where

I decided to work my way around the pool slowly where I soon found several more Emeralds all hunting away in the deep shade though many of these were female without the shaped abdomen and it was so dark here that there was no hope of filming them. In the north west corner I found a ruined building and another Emerald hunting along the shore. This area was actually in full sunlight and I managed to get a decent look at this one with its relatively dark green colouring and its club-tailed abdomen pointing to a definite Downy Emerald.

Continuing along the more open north shore there were Brown Hawkers and Emperors starting to hawk across the main pool with electric blue Damselflies darting low over the water's surface. Back where I'd started I did a second circuit and came across more species with Ruddy and Common Darters, a Four-spotted Chaser and a Golden-ringed Dragonfly all noted. On the Damselfly front there were Blue-tailed, Common Blue, Large Red and Emerald all to be seen. I busied myself taking snaps where I could and enjoying the richness of insect life.

female Common Darter
male Common Darter
Emerald Damselfly
Four-spotted Chaser
After spending far longer than I'd originally intended at this first pool I decided to have a quick look at the second pool before exploring the stream that runs east of these two pools and which was supposed to hold plenty of Golden-ringed Dragonflies. The eastern pool was relatively empty of insect life and I soon gave up on it, turning my attention to the stream instead which turned out to be extremely overgrown, indeed one really had to fight to make one's way along it at all. Banded Demoiselles and Golden-ringed Dragons would zip past as I struggled my way along looking for a more open viewing area. After a while I came to a clearer area where someone had carefully placed a few perching sticks in the middle of the stream. Sure enough after a few moments the first Golden-ringed Dragonfly arrived and helpfully settled on the perch. I snapped away greedily at near point-blank range though sadly my pocket camera and my super-zoom in no way do justice to what was a superb photo opportunity. In fact I've come to realise that in general it's hard to get anything half way decent from my humble equipment but I really don't want to start off down the DSLR route if I can help it.

Golden-ringed Dragonflies
After a while I left the Golden-ringed's to enjoy the sunshine in peace and hacked my way further eastwards until I came to another track that intersected the stream. To the east of this was open heathland with some pools supposedly at the east end of the area. The trouble was how to get to them. I started off trying to follow the stream but it was so overgrown and rutted underfoot that in the end I gave up and headed southwards up to where according to the map there was a proper path. I figured that I would walk along the path until I was level with the bull rushes that I could see in the distance (which presumably marked the pool area) and then I'd hack my way back down at that point. I struggled in the midday heat towards the path but then became distracted when I came across a series of boggy pools just before the road. Here there were loads of Keeled Skimmers and Large Red Damselflies. It was also much easier to walk along this boggy area than on the overgrown heath so I worked my way eastwards here, enjoying the insects as I went.

Keeled Skimmer

Round-leaved Sundew
After a while I was level with the rushes and struck north again towards them. The ground was very uneven and it was hard work in the heat but I made it to the rush area. I was expecting a single large pool but it turned out to be a few small pools with the stream having spread out to run through the grass in a secret and treacherous manner. I say this because on at least two occasions I took a wrong step and found myself knee deep in water and on one occasion I nearly toppled in completely. Fortunately as it was so hot I didn't mind the wetness.

one of the heath pools
There were more Keeled Skimmers here and also a couple of Black Darters, one of the other target species that I was after. After some floundering around in the bog I managed to take a few shots that I was happy with.

Black Darter
Black Darter with a Keeled Skimmer
Eventually I decided that I'd had my fill and struggled my way back again, stopping periodically to view the insects or local flowers. Back at the main track I decided on one last look at the western reservoir pool before heading off home and struck off down a likely looking path that was heading the right way. Sadly this petered out and I had to work my way through the thick undergrowth along the eastern reservoir pool where there was no path at all before coming out at the western pool again. Another circuit revealed nothing that I'd not seen before though there seemed to be greater numbers of everything now that it was even hotter.

Marsh St John's-Wort
Hunger was now starting to get to me so I decided to call it a day and headed back to the car stopping to admire a Silver-washed Fritillary that wouldn't settle for a photo and to take snaps of any flowers that caught my attention as I went.

Common Centaury
Back at the car I got out of my soaking boots and greedily scoffed my snack that I'd left behind in the car as well as gulping lots of water to recover from my efforts in fighting through the undergrowth and bogs in the hot midday sun. Then I fired up the Gnome mobile and pointed it in the direction of home, arriving back later than expected due to some traffic problems on the A34.

It had been a very interesting trip to what felt like a true heathland wilderness which (apart from the two dog walkers first thing) I'd had entirely to myself - something that's not so easy to say these days in this crowded country. I'd also managed to see all my target species which I was really pleased about. I've read (see here) that Warren Heath isn't the great site that it used to be and indeed I only encountered relatively modest counts of the various species but as it was all new to me I was more than happy with my trip.


Paul Ritchie said...

Hi Adam

Glad you enjoyed your visit to Warren Heath.A few pointers regarding Brilliant Emerald; they tend to favour the western edge of the southern reservoir, where there is a small, shallow culvert leading out into the stream - although on my last visit there was one patrolling the western edge of the other pool along the causeway.

Regarding 'jizz', at this site they do tend to fly very low along the shoreline, keeping close in to the bank, often sharing the same course as the Downy. The best way to tell them apart in flight is the Brilliant has a straighter flight pattern, whereas the Downy is more zig-zag. Also the Brilliant tends to fly with the abdomen more level; the Downy always with the tip of the abdomen pointed upwards.

Regarding access to the large peaty pool to the east. Very difficult with treacherous ground, but you can get close by heading north from where the path intersects the stream, uphill a short distance until you reach a narrow path following the tree line.

To the south of the path, obscured by a bank, are some shallow scrapes where Keeled are in abundance, but you can find these along with Emerald and Small Red Damselflies along the path and patrolling the 'puddles' at the far end.

Paul Ritchie

Adam Hartley (Gnome) said...

Hi Paul, thanks very much for your comments and tips. I used your fantastic web-site to do my background research for the trip. From what you say about the Downy/Brilliant jizz I'm even more certain now about the ID of the Brilliant.