Lea Valley mooching

Sunday's sojourn was to Cheshunt and the meadows and tracks by the River Lea Navigation. Being pretty much the first non-rainy weekend in a while, it took a bit of wandering before I got beyond the picnic crowds. Depressingly, a lot of the area’s been scalped in advance of the crowds around the Olympic games and so there aren’t as many big swathes of rough grassland as I’ve seen there in previous years. The first small chunk of meadow was still reasonably interesting. I came across 5 different species of vetch(ling) in one spot – Meadow Vetchling, Common Vetch, Grass Vetchling, Hairy Tare and Smooth Tare (another new species for me). Out of this marginal grassy habitat I also pulled out plenty of Thick-thighed Flower Beetle, Oedemera nobilis; an Orthotylus sp. mirid bug (such a difficult genus!); the soldier beetle, Cantharis nigricans; a Mirid bug, Grypocoris stysi; and a bright white common crab spider, Misumena vatia.

Grypocoris stysi

Misumena vatia waiting for lunch to come to her

A distressed Black-headed Gull brought my attention to a Red Kite floating over the river. There was also a good number of Willow Warblers singing in the area. They’re not the loudest, most variable or most complex of singers but they do my favourite UK birdsong. I picked up another tick upon finding some Cut-leaved Cranesbill and on a Sweet Chestnut found a Red-headed Cardinal Beetle, Pyrochroa serraticornis. I wandered about a fair bit, spent way too long confirming that rose identification is hard and that 99% of the time that Hawk’s-beard will turn out to be Rough Hawk’s-beard. Up on some Common Hogweed I also saw this very confiding large hoverfly, Volucella pelluscens.

Volucella pelluscens

Finally I walked back through the ill-planned disc golf area where lack of use has allowed the grasses and clover to grow higher. The odd-looking chain-and-basket goals poking clear of the vetch or hiding behind bramble and hawthorn shrubs say a lot about the council’s aspirations, the extra funding it’s presumably had and how out of touch it must be with the local population. In amongst this derelict recreation ground were a lot of Leptogaster sp. robberflies; far more than I’d found elsewhere. Showing red hind legs, I’m fairly sure these were Leptogaster guttiventris. The final and most surprising find was a small bunch of Bee Orchids! I could almost have stepped on these beauties and I’m really glad I didn’t. I know they’re fairly common but for me they were completely new, completely different and completely self-found. I took way too many photos. I don’t think I’ve ever enjoyed seeing a wildflower quite like that before.

Bee Orchid

It doesn't look anything like a bee to me but then I don't view life in ultraviolet through hundreds of ommatidia

Hartslock

I finally made the trip to Hartslock after trying to make it there for a sunny May day 2 years in a row. It was definitely worth the wait. For such a relatively small site it has an absolute abundance of rare and interesting organisms upon it. I started out by walking by the railway sidings to the Thames and ended up stopping along the way to ID some plants I didn’t recognise. All fairly common stuff but ones I either hadn’t figured out before or hadn’t found yet. Sticky Mouse-ear, Field Madder, Field Pansy, even Common Storksbill and Field Forget-Me-Not were all new to me. In this one little area bordering the railway lines and with intensively farmed land to either side I still found 20ish species. While hunched down and looking at the ground and a flower key I must have been fairly inconspicuous (or looked like future carrion) as I heard a gentle woosh sound and looked up to see a Red Kite about 10 feet over my head. It circled about nearby and slowly rose up on a thermal until it presumably had enough height to track off wherever it was going.

Field Madder

Common Storksbill

Field Forget-me-not

Walking down the Thames, I didn’t see any of the Club-tailed Dragonflies or Beautiful Demoiselles I’d seen the year before. It was probably a bit early given the cold spring we’ve had but a few club-tails have been seen in the area already. The Thames-side path had the usual thick banks of vegetation with lots of broad-nosed weevils (species in the sub-family Entiminae), alderflies, 24-spot ladybird, a few mayflies and my  first cantharid of the year with Cantharis rustica (how this large soldier beetle with a heart shaped mark on the pronotum managed not to earn a common name I’ll never know). Running around on the muddy track was a ground beetle – Notiophilus biguttatus. These small (~5mm) beetles have enormous eyes on them much like the more charismatic tiger beetles and fill a similar niche as an active sight-and-chase predator. Also the most photogenic Lords n Ladies I’ve ever seen:

The Hartslock Nature Reserve sits up on one of the chalk hills that the Thames sidles by on its way out of Oxford. It consists of 5 small compartments of downland in different grades of scrubbiness. The presence of lady and monkey orchids draws in a lot of photographers and botanists in the spring so the warden and volunteers cordon off the most “orchidy” section of the hillside. There were quite a lot of people with cameras at the top as I came in so I took a more circuitous route, the long way around the cordon. Chris Raper, the site warden was there with his volunteers, mapping the orchids. He kindly pointed out one of the first flowering Monkey Orchids on the site which was quite diminutive and actually on the opposite side of the track from the cordon.

Monkey Orchid

Chris is also an entomologist specialising in Tachinid flies. He seemed quite proud of his site and rightfully so. They have both grizzled and dingy skippers on site as well as common blue, small heath, peacock and brimstone. They’ve got Bastard Toadflax growing on site (not in flower at the moment and not one I know vegetatively) and the Down Shieldbug, Canthophorus impressus – a quite rare species associated with this plant and only found in a few sites in southern England. There’s also Lady Orchid, hybrid Lady/Monkey orchids, Pasqueflower, Chalk and Common milkworts, Common Rock-rose, Salad Burnet and other chalk downland plants. This is also a site for the rare mining bee, Andrena hattorfiana.

Cryptocephalus aureolus

Up the hill I noticed an awful lot of distinctive orange and black bees, Osmia bicolor. This species will use snail shells to nest in and I even found one provisioning one of its cells. Two Dandelion-a-likes kept me confused for a little while. One of them was Lesser Hawkbit but the other was difficult to determine.

Osmia bicolor

Bee butt

At the very top I found out what had the photographers there in such numbers – the main patch of lady orchids and hybrid monkey/lady orchids.

Lady Orchid

Lady/Monkey Orchid hybrid

Garden Chafer

The rest of the reserve sees less foot traffic and is more open with a solitary large beech tree watching over the Thames as the reserve rounds into a dry valley tributary. This was a truly gorgeous spot for lunch. The first garden chafers of the year were in the beech tree alongside several arboreal carabids and a large entimine weevil species I’d been seeing everywhere (I have some microscope time ahead of me). In the short grass here I found my first ever (confusingly six-petalled) Common Rock-rose. Down in the dry valley, the very short sward was peppered with blues and purples of various hues with common and chalk milkworts, common green field speedwell, bugle, mauve depigmented common milkwort and in one small area: Pasqueflower!

What beauties! And so hairy! Well I’ll let them speak for themselves:

Pasqueflowers

These flowers are very picky about the kind of habitat they can use – the current issue of British Wildlife has a large article on the difficulties in conserving land suitable for this species. Hartslock truly is a special place.