Thursday, July 30, 2009

Snail in a Hurry

A few days ago Ron Bloomquist published at interesting photo of a ‘hiccuping’ intermittent snail trail on his Walking Fort Bragg blog, and was wondering how it might have come about (see .This snail wandered across my path today and this series of photos shows quite nicely how hit moves, with a head-to-tail wave of muscular contraction along its foot which is slightly arched – check out the way the gap under its foot moves backwards as the snail moves forwards in this top-to-bottom sequence (double-click the images for a larger, clearer view). It occurs to me that if the snail was crawling along a hot road surface and wanted to minimise the exposure of its foot to the heat it might well arch its foot even more, and might leave a trail like the one Ron saw...........just a thought.

Tuesday, July 28, 2009

Dark Green Fritillary

Like many natural history bloggers, I tend to tread the same paths regularly. There are some places that we’ve visited now for 35 years, so we’ve got to know them pretty well and when something unusual appears it tends to catch the eye. Which is exactly what this Dark Green Fritillary did, on a footpath near Stanhope in Weardale this morning. We’ve walked this path several times a year for three and a half decades and this is the first time we’ve seen this handsome butterfly there. Usually this is a species that’s very active and so is hard work to follow. I chased one for a frustrating hour on a hot afternoon in Norfolk recently without getting a decent photograph but in this morning’s showery weather I was able to approach closely without too much effort.

Monday, July 27, 2009

A Miracle of 16th. century Medicine

The herbal uses of many plants, like the two woundworts shown here, are preserved in their common names. Hedge woundwort Stachys sylvatica (bottom photo), with spikes of purple and white-blotched, hooded flowers is common along woodland edges and is most easily recognised by the appalling stench of its crushed leaves. Marsh woundwort Stachys palustris (top photo), with less pongy leaves covered with soft greyish hairs and with pink flowers, is restricted to damper habitats. Confusingly, the two species tend to form hybrids with intermediate chacters when they occur within bee-foraging proximity. According to the 16th. century herbalist John Gerard, marsh woundwort (or all-heale, as he also called it) has miraculous powers. In his famous Herbal of 1597 Gerard says that marsh woundwort first came to his attention when he met a labourer who had cut his leg to the bone with a scythe. Gerard recounts how the victim crawled to a patch of woundwort and “tied a great quantitie of it unto the wound with a piece of shirt”, whereupon the pain and bleeding ceased and he could resume work. Within seven days, he claimed, the wound was healed. Impressed with the labourer’s experience, Gerard went on to test the efficacy of woundwort on two of his own patients. The first had been run through with a sword, puncturing his lung, but Gerard claimed to have “perfectly cured him in a very short time”, using the labourer’s method with the addition of some turpentine, oil of roses and “a quart of good claret wine”. Even more improbably, he then claimed to have successfully treated an attempted suicide who had cut his own throat and stabbed himself in the chest and abdomen, restoring him to good health within twenty days. Far-fetched for sure, but back in Gerard’s day the tall stories in his Herbal – and the wild plants of the hedgerow – were the best medical resources available. Interestingly, he describes marsh woundwort as growing “in the medowes by Lambeth neere London”. I wonder if there’s a marsh woundwort plant growing anywhere within the Borough of Lambeth today?

Sunday, July 26, 2009

Harvest Approaching

Cereal grains swelling in a ripening field of barley in Teesdale, under a thundery summer sky. Ten thousand years ago our Neolithic ancestors first cultivated cereal crops in the Fertile Crescent in the Near East, paving the way for farming systems where the many would come to depend for their staple food on the efforts of a few. A ripening wheat or barley field is such a familar sight that we tend to take the skills of the plant breeders, agronomists and farmers for granted - even though most of us are totally dependent on them.

Thursday, July 23, 2009

Unlucky Moth

Large yellow underwing moths have been hatching out all over our garden during the past week but this one chose a very bad moment to emerge from its cocoon - just as a passing wasp was looking for a meal. Although they have a liking for sweet things, wasps are ferocious carnivores and kill vast numbers of garden pests, which they feed to their brood. They'll tackle prey much larger than themselves and I've several times seen a wasp kill a caterpillar and chew it into bite-sized chunks small enough to carry back to the nest. I've never seen one tackle something as large as this moth. I noticed the moth lying on its back on the path, fluttering its wings weakly - and then I saw the wasp attacking it, repeatedly stinging its prey's abdomen and trying to chew off the moth's head and legs. At this stage the moth was still fighting back and briefly succeeded in dislodging its attacker. The wasp seemed to be very irritated by the caterpillar hairs on the cocoon (still visible in the top photo under the tail of the moth) and by the hairs on the moth's body, and it stopped its attack several times to clean the hairs off its eyes and antennae (bottom photo). Then it retreated for a while, waited for the venom to take effect, then returned to finish its meal. After about half an hour, all that was left of the moth was the wings and holow thorax. Its adult life span had been measured in minutes.....

Monday, July 20, 2009

Botanical Mysteries 2: the Strange Case of White-Flowered Marsh Thistles

Marsh thistle Cirsium palustre flowers are generally deep purple (bottom photo) but, wherever you go in the North Pennines, you begin to notice white-flowered plants (top photo) once you climb more than about 1000 feet above sea level. As you go higher, the white flowered forms become more prevalent. Why? One suggestion, put forward by Dave Mogford at Oxford University back in 1974, was that white-flowered forms tend to attract more bumblebee pollinators, so it pays to be white at higher altitudes, where bumblebees are fewer. If that's the case, why aren't there white-flowered populations of other thistle species at higher altitudes? There’s scope for amateur naturalists to make some observations to check out this explanation....................

Sunday, July 19, 2009

Botanical Jewels

We spent most of the afternoon in the garden, harvesting fruit and vegetables – broad beans, peas, gooseberries, blackcurrants - and these white currants. Don’t really know what to do with the white currants, because they're so full of seeds. We really only grow them because we like the way they look – dangling bunches of botanical jewels on the bushes. Nearest thing in the plant world to a pearl. Anybody got any good white currant recipes?

Friday, July 17, 2009

An Alternative Point of View

One of the advantages of compact pocket digital cameras is that they offer amazing depth of field in images. Another is that they make it easy to take pictures from unfamiliar angles – from ground level, for example. Put the two together and you get a different perspective on the natural world, that’s more familiar to a ground feeding bird or small mammal that spends it’s time looking upwards, rather than to we humans who inevitably see much of the living world from a lofty perspective. From the top: germander speedwell, foxglove, hogweed and spotted orchid.

Thursday, July 16, 2009

Wear and Tear

Take a close look at enough insects and other small invertebrates and it soon becomes apparent that they simply wear out quite quickly. The wing tips of the crane fly in the bottom photo are tattered, presumably from the constant battering that they receive as the insects flutters amongst the grasses. It's also lost a leg, a common cranefly affliction. By mid-summer the wing tips of many insects – especially bumblebees, show severe wear as they age, which must affect their flight efficiency and the amount of energy they need to expend just to remain airborne. Butterfly and moth wings shed their coloured scales quite rapidly as the insect ages. The wings of the 6-spot burnet moth in the middle photograph have lost so many scales that they’re partially transparent. Mishaps must account for the fact that the female wolf spider in the top photo only has five legs. Young spiders can regenerate legs provided that they can still moult, but this adult will have had its last moult, so she'll have to struggle along, carrying her egg sac, on just five...

Wednesday, July 15, 2009

Botanical Xenophobia?

There’s a long-standing belief that dense riverbank stands of Himalayan balsam Impatiens glandulifera – like these plants flowering beside the river Tyne at Corbridge - represent a major threat to our native riverbank plants. The press loves a good ‘alien invader’ story that predicts the extermination of our native wildlife by some botanical ‘foreigner’, and it’s true that some introduced plant species that have escaped into the wild, like Japanese knotweed and Australian swamp stonecrop for example, have damaged natural habitats, but in the case of Himalayan balsam the threat is more imagined than real. Although it’s a tall, fast-growing and very conspicuous plant it’s an annual, and doesn’t compete very effectively with established riverbank perennial native plants that have dense root systems. Two recent research projects have demonstrated that it isn’t a dire threat to our flora and one very recent one has shown that it’s a positive asset as far as bees are concerned. It’s a rich source of nectar and pollen and bees visit it constantly. Sadly, once these 'alien invader' stories take root they tend persist, no matter how good the scientific evidence is that shows they are a myth. So I dare say well-meaning but misguided ‘conservationists’ will organise many more ‘balsam bashing’ events to tackle this imagined threat. Still, the plant is well established almost everywhere now, and its exploding seed pods disperse its seeds very effectively, so it will probably continue to provide a valuable food source for our hard-pressed bees for a long time to come.

Tuesday, July 14, 2009

Sawbills on a Sunny Afternoon

This family of goosanders were enjoying the sunshine upstream from the bridge across the river Tyne at Corbridge (bottom photo) this afternoon . In the thirty five years that we’ve lived in the North East goosanders have become an increasingly frequent sight on the rivers here – something to gladden the heart of ornithologists but not quite such a welcome development for anglers, who resent the goosander’s formidable fishing skill. The serrated edge to the bird's beak is beautifully adapted for gripping a wriggling fish. This is a small family group – we once saw a duck with twelve ducklings on the Swale in Yorkshire but as many as 16 eggs have been recorded in a nest, which goes quite a long way towards explaining why this species has colonised new rivers so successfully. That mottled pattern of downy feathers on the ducklings breaks up their outline very effectively, against the rippled shadows and highlights of the river. Double-click on the images for a larger picture.

Monday, July 13, 2009

Gentlemen, Choose your Weapons!

When I was a kid our weapon of choice for fun-fights on the way home from school was either a handful of sticky-Jack Galium aparine
or the seed heads of this grass, wall barley Hordeum murinum. Used as darts, they’d sticky satisfyingly into the woolly school jumper of an opponent. These days, I tend to appreciate this common grass for its aesthetic qualities, especially when its long awns catch the early morning sunlight or are covered in dew.

Sunday, July 12, 2009

Out of Nowhere

We came across these long-tailed tits when we were walking along a footpath that passed through a dense thicket of small trees. Suddenly a party of six – probably all fledglings from the same nest – were all around us, acrobatically searching every leave and twig. And then they were gone, as suddenly as they’d arrived. I’m very taken by these charming little birds, that have begun to visit our garden in winter. Incidentally, in the bottom picture the bird is on an elm twig, identifiable by the leaves and the corky ridges on the bark. Dutch elm disease may have done for mature English elms that once graced hedgerows in the landscape but the young trees don't succumb the disease until they are a few years old – so scrub elm is still a good feeding habitat for many birds.

Saturday, July 11, 2009

Summer in the City

We did a bit of botanising more or less in the centre of Newcastle today. Tucked away in little pockets of waste ground there are all sorts of rural wild flowers growing in unlikely urban habitats. Are they accidental arrivals, originating from seeds brought in by birds, traffic and people, or are they remnants of a past flora that existed when this sprawling city was still green fields? A bit of both, I would guess. The lady’s bedstraw (top photo), flowering in the shelter of a billboard on the road to Byker, belongs in a hay meadow rather than in a tangle of overgrown shrubs and litter. The tansy (second photo), with yellow button flowers and aromatic foliage, was flourishing in a gap between a wall and a tarmac-covered car park, a long way from the hedgerows and riverbanks that are more familiar natural habitats. Yellow toadflax (third photo), established in the crevice between a factory wall and the pavement is a refugee from grassy places and hedgebanks, but seems to be thriving in the urban jungle. Rose-bay willow herb (fourth photo from top) colonises waste ground everywhere via its wind-blown seeds but how does wild parsnip, in the foreground of this photograph, get around the city and appear as a regular coloniser of disturbed soils? Wherever it grows, its flowering shoots become infested with aphids, attracting ladybirds (bottom picture). It’s tough on the city streets, but nature is tougher..........

Friday, July 10, 2009

Grasshoppers are an essential element in the soundtrack of summer. Just listening to their song conjures up mental images of warm summers days and picnics on dry sunny banks where the grasses are slowly turning straw-yellow in the heat and drought. The hotter it gets, the louder the grasshoppers seem to chirrup – although the individual in the top picture looks like he’s feeling the sweltering heat and wiping the sweat from his brow. There are only 27 species of grasshopper and cricket native to the British Isles so it isn’t too daunting a task to get to know them all. There’s even a web site entirely dedicated to them at

The Enduring Mystery of the Red Carrot Floret

Charles Darwin, and subsequent generations of botanists, have been intrigued by the single red floret that often appears in the middle of the inflorescence of a wild carrot Daucus carota. One hypothesis – that the dark floret acts as a decoy, resembling a fly and attracting further flies to mate with it, thereby improving wild carrot’s chances of pollination - has so far remained unproven, so the conclusion that Darwin came to in 1888* - ‘That the modified central flower is of no functional importance to the plant is almost certain’ still stands. But if you are a naturalist with time to spare, and are prepared to count and statistically analyse the relative numbers of flies on intact infloresceneces and those with the red floret removed, you might still prove him wrong.........
*Darwin, C. (1888) The Different Forms of Flowers on Plants of the Same Species, 3rd edn. John Murray, London, UK.

Thursday, July 9, 2009

Ear-splitting oystercatcher

Over the years I’ve been assaulted by a wide variety birds when I’ve strayed too close to their fledglings. I’ve been dive-bombed by terns, intimidated by short-eared owls, vomited on by fulmars and lured away by lapwings and ringed plovers that were pretending to be injured. However, this oystercatcher takes the award for the noisiest defence of its brood, flying around my head and letting loose a barrage of hysterical high-pitched alarm calls. Still, it did mean that it came close enough for some decent pictures….

Wednesday, July 8, 2009

Wet Water Avens

If you’re British, you somehow have to find a way to enjoy the subtle pleasures of wet summer these ripening seeds of water avens, perhaps, appropriately bejewelled with water droplets.

Tuesday, July 7, 2009

Food That Fights Back

All juvenile animals have to learn by trial and error what’s safe to eat. The young house sparrow in these pictures seemed to be still quite low on the learning curve. It grabbed the violet ground beetle that scurried within easy reach, then almost instantly dropped it (second picture from top). Some beetles exude foul-tasting fluids when they’re assaulted; I don’t know whether this species does or whether it was just its wriggling that made the sparrow drop it. Its assailant persisted and after further struggles the unfortunate beetle became a crunchy meal for a hungry sparrow.