Wednesday, 24 July 2013

Sounds of summer

It's been seven years since we had a nice spell of weather like this. It feels almost like living that idyllic early scene in Puckoon, in " unexpected burst of hot weather. Saffron coloured in the bleach early sky, the sun blistered down, cracking walls and curling the brims of the old men's winter-damp hats...", though I (hopefully) bear little resemblance to Dan Milligan. And there's no nobbly brown dog in the vicinity. What there are, though, are grasshoppers. Stacks of 'em.

A good patch of long grass, paper-dry rustling already with the breeze, suddenly comes alive when the sun begins to crank up the heat in mid-morning. The plants suddenly seem to sizzle and whisper with the songs of various species, all clinging cryptically to stems and leaves or huddled against fragments of plants on the ground. Every footstep is accompanied by an explosion of tiny forms, bursting into action and springing wildly in every which direction.

A short, 'Schritt. ... Schritt. ... Schritt' heralds Field Grasshoppers, Chorthippus brunneus, a dust-brown and faded yellow-green with a blushing abdomen tip and two neat little angles on top of its thorax (the pronotum, if you prefer), rather like the mathematical operators greater than and less than: > <

Female Field Grasshopper. Note that the pale angles on the pronotum don't meet the hind edge of the pronotum either, and that the antennae are not clubbed, unlike some otherwise similar species.

A slightly drier, softer 'zee-zee-zee-zee-zee' gives away Meadow Grasshoppers, Chorthippus parallelus, which tend to be brighter green, striped dandy-ish beasts with - slightly belying the scientific name - gently incurved marks on the pronotum: )(

Meadow Grasshopper. Posing.

Meadow Grasshopper. The pale lines on the pronotum are not only gently curved, but stretch from end to end of the pronotum.

A bright green Meadow Grasshopper. Note also the short wings: generally this species has rather stumpy wings, but when populations grow too dense, a whole load of longer-winged individuals emerge and head off for pastures new.

The crickets are less conspicuous and also quieter, with a rather ventriloqual quality. A sibilant 'srrrrrrrrrrrrrrrrrrrrr' from rank grass suggests that a Conehead (Conocephalus) of one or other species is lurking, but without seeing it I'm not sure of the identification. The likelihood is that it's Short-winged (C. dorsalis), but you never know...! Finally, a surreptitious movement gives away a Dark Bush-cricket Pholidoptera griseoaptera, looking a little like a dark spider scuttling across the ground. Their staccato 'Tschr. ... Tschr. ...Tschr.' will soon be ringing from the depths of almost any patch of slightly scrubby vegetation .

Soon it'll be the season for the outrageously loud Great Green Bush-crickets Tettigonius viridis, which can be clearly heard from a passing car, even at a fairly high speed, their penetrating 'TCHR-TCHR-TCHR-TCHR-TCHR-TCHR-TCHR-TCHR-' assaulting your ears as you pass a patch of brambles.

Sunday, 14 July 2013

Hot in the shade, hotter on the moors

I joined a couple of friends on Dartmoor yesterday to help them mop up the last few of their nest records for the summer. As they've found some 200 nests over the course of the season on about five square kilometres of moorland you'd be forgiven for thinking there was little left to find there, but that's never quite the case.

We started out by watching a Tree Pipit which was behaving as if there might be a nest nearby, but eventually decided that it was just guarding fledged young from a nest that had already been recorded, so we moved on up the slope to the area my friends wanted to concentrate on.

We weren't hugely successful in the grand scheme of things: finding only a new Whinchat nest with a full clutch of five eggs and a second brood of Stonechats with seven pulli (this pair had lost their first clutch), but we also checked on a number of nests that had been found previously: a brood of Skylarks had apparently fledged successfully, a female Linnet sitting on a now-complete clutch and another pair of Whichats which had - for the third time this season - had  their eggs predated (probably by a fox, as the nest had been pulled out and left on the ground nearby).

Despite it being a rather quiet day in terms of nests, the site was alive with wildlife, a sign of how useful this recent spell of decent weather has been. The air resounded with a constant 'tchirrp' of Meadow Pipits warning their young to stay out of sight, mingled with the melodious bubbling song of Skylarks above us. A male Reed Bunting rattled out his song from a patch of low Western Gorse whilst Linnets chirruped to and fro over him. Everywhere were Blackbirds shuttling between the open moorland and the adjacent scrub where their second broods sat waiting for more and more food.

It wasn't just birds, though they were perhaps the most obvious part of the day. Butterflies were out early with the rapidly warming air: Small Heaths and Meadow Browns bouncing erratically up and down over tufts of grass, whirring up into spiralling chases when another of their species approached too close, though whether fighting or attempting to impress a potential mate is impossible for me to tell. Field Grasshoppers sizzled staccato bursts from the tussocks and a Goldenring or two drifted casually through the cloud of flies and midges, snacking at will. As we walked through the grass, moths shot away from us (I could only pick out Emerald and Brown Silver-lines as we went, but there were many others too), Common Lizards rustled off, a tell-tale sliver of brown wriggling between the stems, and a brief glint of rich orange drifting through the air resolved into a fine fresh Dark Green Fritillary... Let's see how long this weather lasts!
Dark Green Fritillary (Argynnis aglaja) - a flake of orange gliding across the open moors, or down on the coastal heaths and dunes, often proves to be this species.

Goldenring (Cordulegaster boltonii) - this one resting up and digesting between flies.

Meadow Brown (Maniola jurtina) taking a drink to refuel between those energetic spiralling aeriel encounters.

Common Lizard (Zootoca vivipara), sunning itself