Saturday 30 April 2016

April’s Emeralds: the Cassida "Tortoise" leaf-beetles

The Tortoise beetles come out of their shells in April. They are well camouflaged and tortoise-like in appearance, with modified thorax and wing cases which are flattened at the margins to conceal their head and legs. An inexperienced eye could be forgiven for confusing them as a type of ladybird, if it does not miss them altogether. Once you have your eye tuned into them, they can be found in good numbers, blending in well with the green leaves that they bask and feed upon. There are twelve species present in the UK, most of which are green, but with a few exceptions - a couple of which are a stunning red and black (one of which - Pilemostoma fatuosa - is not one of the Cassida species, but it is closely related and still one of the "cassidine" tortoise beetles in the Cassidinae subfamily of Chrysomelidae leaf beetles).

Of the twelve UK species, personal experience suggests that the two most commonly seen species in the Newhaven area are Cassida rubiginosa and Cassida vibex, both of which can be found now basking on the leaves of knapweeds and thistles. C. rubiginosa, a species which has been used as a bio-control against thistles in Canada and New Zealand, is named after the small rust-coloured marks on its elytra (wing cases) behind the thorax, but C. vibex has a much more prominent red-brown longitudinal band tapering along its wing cases (vibex meaning a lash or streak).
Cassida rubiginosa mating pair
Cassida vibex basking on knapweed

There are several other species which are present in southern England and should be fairly easy to find on the Downs and along the Ouse Valley north of the Seahaven area. The Green Tortoise Beetle (Cassida viridis) is larger than the two species above and wholly green. It is found near water on dead-nettles (Lamiaceae) such as mints and gipsywort. The smaller, duller Cassida flaveola is found on pinks (Caryophyllaceae) including Stitchwort (Stellaria). The beautiful Cassida vittata with its distinctive longitudinal metallic green wing stripes feeds on many different plants in coastal areas, but is also an agricultural pest of beets and spinach. The similar Cassida nobilis, with its golden longitudinal bands, which feeds on goosefoots (Chenopodiaceae) is found inland from coastal areas.

The tortoise beetles feed on a number of plants, but mostly upon members of the daisy (Asteraceae) family including thistles, knapweeds and fleabane. They like a nice warm, sheltered spot out of the wind to bask on a leaf. If you choose a good location and if the weather is good, you could be rewarded with an emerald-encrusted experience - but careful searching is required because they really do blend in and they have an additional means of camouflage, which conjures a parallel image of the Cosmic Tortoise.

The cosmic tortoise is a mytheme (or creation myth) which commonly occurs in tribal mythology around the world. The tortoise goes by different names, such as the 'World Turtle', 'Divine Turtle' and, by the Native American tribes including the Iroquois and Lenape, as the 'Great Turtle'. Turtle and tortoise are interchangeable. The Chinese, typically, have to cut off the turtle's legs and use them to support the heavens after the mountain which had been doing the job - Mount Bizhou - was damaged. Art imitating life there, perhaps? In Hindu myth the turtle is known as Akupāra, which supports upon its back four elephants, which in turn support the world. Brewer's Dictionary of Phrase and Fable (15th Edition) gives the tortoise's name as Chukwa, which supports the elephant Maha-pudma, which in turn supports the world. An excellent account of this and other mythemes involving reptiles and amphibians is also given in the excellent and visually stunning book Eye of Newt and Toe of Frog, Adder's Fork and Lizard's Leg by Marty Crump (2015).

Akupāra supports the four elephants, which support the world

How does tortoise mythology warrant a digression from tortoise beetles? Tortoise beetles certainly do not support the world, via one or four elephants, upon their backs, but they do place something on their backs which further improves their camouflage: excrement! This is a fact which should not be concealed from the reader, but it is revealed to you in the hope that it will not turn you away from the potential for admiring these stunning little invertebrates. It is agreed that their 'faecal shield' poop-smearing behaviour is unpleasant, but the fact that so many are sporting the stuff demonstrates that it is a successful evolutionary adaptation, which of course is to be applauded. But it does also make them harder to find.

Cassida rubiginosa wearing a 'faecal shield'

How best to begin looking? One suggestion is to target specific plants in sheltered locations out of the wind on a warm day. I was rewarded with a dozen and a half Cassida rubiginosa and a few Cassida vibex sightings along a short stretch of path at Mount Pleasant the other day by looking for only a few minutes at knapweed plants, which are not yet in flower but still stand out distinctively from other plants amongst the downland grass. The beetles sit quite overtly on the knapweed leaves and are quite approachable. They play dead when disturbed and just drop to the ground. A single beetle on a leaf is often one of several on the same plant. The best way to get started, like many things in entomology, is to just get out there and enjoy the thrill of the hunt and to just enjoy being outside with the sun on your back away from the chill of the spring breeze and away from the mundane tasks of everyday life. Someone else is taking care of things while you're away. There's a tortoise supporting us all.

References:

Brewer's Dictionary of Phrase and Fable, 15th ed. 1995. Room, Adrian (Ed.). HarperCollins: London.

Eye of Newt and Toe of Frog, Adder's Fork and Lizard's Leg: The Lore and Mythology of Amphibians and Reptiles. 2015. Crum, Marty. University of Chicago Press: Chicago.

Cassida rubiginosa basking on knapweed
 




Sunday 24 April 2016

Ghosts of East-side beach

Many wrecks are stranded along this beach.


I am walking along the western half of Seaford Bay towards the mouth of the River Ouse, where waters and silts from the catchment between here and Upper Beeding bloom in a final flourish from the river mouth into the sea. I have walked from Denton over downland via Bishopstone and The Buckle. The shingle underfoot gulps the energy from every stride as I trudge along it. I pause and ponder the past and see that this land is one of relics and ghosts. There is much happening close to here, but very little here itself occurs, little other than the circadian pulses of wavelet and tide, of morning and afternoon dog-walkers, of weekend beachcombers, and the passing of the weather and the seasons - each beating its own rhythm like the mainsprings of many clocks.

There is plenty of wildlife here to be seen. Amongst the birdlife alone one could see Ringed Plovers nesting in small undulations amongst the shingle and Purple Sandpipers picking at low tide amongst the encrusted skeleton of the east pier or hunkered down waiting at high tide for its ebb. Great Crested Grebes and Red-breasted Mergansers dive in sheltered, shallow water at quiet times; and gulls own the air above us all.

Short Type 184 seaplane, (public domain picture credit)
The sea to the south and a tidal creek to the north have created an in-between spit of land which is caught between the heartbeat of human habit that speeds past by boat or train, discarding relics in a multifarious eddy. Here are the old creek and its ruin of Tidemills, here also the ghosts of aircraft hangars and a slipway serving a First World War seaplane station, where Short Type 184 seaplanes performed anti-submarine patrols until the end of the war, and here also the ruins of the Chailey Heritage Marine Hospital, a recuperation home built in 1924 for disabled boys. It is hard to imagine now that the  Newhaven Marconi Radio Station operated from just in front of where I am standing, its tall white antenna visible from miles around. The ghosts of an astonishing array of spent industries all wither before me and before the eroding effects of the sea and the wind, run aground by time and progress like some sad Golgotha of storm-weathered bones. These and other less mighty structures have been swept up by the unforgiving temporal wave and cast high and dry upon on the strandline.

Newhaven east-side beach - seaplane station under construction (credit)
Chailey Heritage hospital, Newhaven East-side beach (photo credit)

Standing in mute reflection on this tongue of vegetated shingle, I am in the midst of activity: trains, ferries, tankers, container ships and fishing boats are all within sight and earshot. Yet here I find myself on a temporal hard-shoulder watching life surge past. I am in a grey, marginal world and, while I am here, I feel that I am entangled in the sidelines of time itself. The weather adds to this feeling: it is a grey, calm, silent day and the horizon is suspended somewhere between sea and sky in a vast sheet of brushed aluminium.

Along the strandline rests the remains of innumerable shellfish. We are taught as children that the some of the shells contain echoes of the sea when placed against the ear. Each shell is an echo of a former life reborn as a pretty, collectable trinket, a memory-echo of a seaside visit. If innumerable shells are here at this moment, how many shells, how many spent lives have stacked up along this one beach throughout history?

Each individual shell and half-shell holds within it the story of a life passed. For each half a bi-valve (a valve!), where now is its counterpart? How long since they hinged and jointly protected soft tissue within? There is something horrific resting quietly amongst these emaciated strandline shells which can be given flesh and made tangible by imagining their number replaced with the equivalent of something more charismatic: a wreck of dead seabirds, a beached pod of whales. Imagining this reveals something of the true extent of the horror. Do they now become something more than simple shells? Does the thin veneer of grey periostracum, violet in life, but soon to fade and peel in death, reveal something stark about the exquisite fragility of life itself?

Amongst the myriad species is the Rayed Trough Shell (Mactra stutlorum). This is an edible clam which lives burrowed in sand and gravel beneath shallow seas. The rays radiating out from the umbo suggest captured sunlight through water. Just a stone's-throw from where I am standing, in 1861, when the mouth of the Ouse river was being deepened, the Rayed Trough Shell became the object of a feeding frenzy. Paul Chambers, in his book British Seashells (2009), describes the drama:

...a harbour channel in Newhaven was being deepened using an industrial steam dredger but as the sediment was churned up, so thousands of rayed trough shells were disturbed and washed onto the beach, much to the delight of the local inhabitants. The Newhaven fishermen took advantage of this bonanza by clustering their boats around the steam dredger to haul up both the shells and fish that were being thrown up with the sediment.

Mactra stultorum - the Banded Ray Shell (credit)
One can imagine the noise from screeching gulls, excited townsfolk and booming industrial machinery. The commotion is long since silenced, broken today only when children fish and jump into the water from the skeleton of the eastern arm on hot summer days, or when dogs race excitedly across the wet sand at low tide, and of course with the passing of marine traffic and the awesome bass hum of ferries.


I make my way down the shelving shingle and to the sea, which is high but just on the ebb. Wavelets lap against the stones and disappear in tiny raptures. Several Purple Sandpipers are dotted along the pier, waiting for the tide to fall. The strandline contains a wealth of natural flotsam: cockles, otter-shells, common and American limpets, banded ray-shells,  scallops, oysters, razor-shells, mussels, netted and common whelks and their familiar spongy egg-balls, various sea weeds, crab-shells, cuttle-fish, mermaid's purses. Their Latin names slip off the tongue and conjure oceans of wonder: Patella vulgata, Littorina littorea, Crepidula fornicata, Ostrea edulis, Chlamys varia, Pecten maximus, Acanthocardia tuberculata, Laevicardium crassum, Mactra stultorum. I have counted more than two dozen species of marine mollusc here, but the natural flotsam is dwarfed by the volume of non-natural, human-induced filth. This is the swill and slop of a castaway consumer culture, the dreck and dregs of our age, a loathsome littoral litter, the feculence of efficiency. One cannot help but cast a sheepish eye back to 1861 and wonder how we came to navigate so far off course from a comparative harmony with the natural environment*.

Modern strandlines are a depressing example of human disregard for the natural environment. Amongst the world's litter along this beach there is a scum of palm oil or paraffin wax. This is a wreck of marine pollution cast adrift by humans, swilled out of some passing ship's hold to form a polar sea in miniature as fat-bergs bob and drift coast-bound at the mercy of tide, wind and wave. Plastics abound - memories stirred up by a stormy sea.

Nobody knows how long plastic remains in the marine environment. It doesn't biodegrade; it is broken into ever smaller pieces and is inadvertently ingested by the smallest marine species all the way up to the largest. Once it is deposited into the water it might remain in the sea or along strandlines for a very long time. Our grandchildren, nine or ten generations into the  future, or perhaps a hundred or more generations of marine molluscs into the future, might still be affected by what we fail to properly dispose of today. This is not my prophecy: we could end up with as much plastic in our oceans as fish. But it is complicated: food wrappers have helped to protect humans from typhoid and other infectious diseases and reduced food costs by prolonging shelf-life. Plastics are useful as well as harmful, but we need to do better when we have finished with them. People the world over urgently need to support the use of biodegradable and compostable plastics and avoid persistent plastics where possible.

Forget the echoes within those empty, spent shells which pepper the strandline. The longest, loudest echo on this beach is made in a faraway country and made of plastic.




*Comparative harmony with the natural environment - even back in 1861 catastrophic environmental change was old news, even if the concept of it had not been fully cultivated.

Reference:
Chambers, Paul. 2009. British Seashells - A Guide for Conchologists & Beachcombers. Remember When: Barnsley. 

Friday 15 April 2016

Window watching, serendipity and a tiny moth

The playwright Katori Hall wrote that serendipity always rewards the prepared.


There I was, shortly before lunchtime on Thursday 14th April 2016, sitting at my desk in Southover House, pausing mid-letter to watch the Rooks zip from their rookery at the front of the office past my window towards Pelham House and back again with their beaks stuffed with food, when a much smaller movement caught my eye. There, on the inside of my opened window was a small dark moth. Of all the 200-odd windows in all the rooms at Southover House, it chose mine! I dashed to the Rangers' desks close by, grabbed a pot and, a few seconds later, the little moth was safely inside.

Dan and I spent a few minutes of our lunch break checking through the list of species belonging to the Gracilariidae family of moths until Dan suggested that our little moth was Phyllonorycter rajella. It was confirmed the next day by County Recorder Colin Pratt.

Phyllonorycter rajella - the Common Alder Midget, found on Alder trees and on the insides of office windows


Phyllonorycter rajella (or the Common Alder Midget) is new to me - I had never previously seen it, mainly because its food-plant, Alder (Alnus), doesn't grow on the chalk Downs where I do most of my entomology. There are plenty of Alders close to Southover House though, in the Southover Grange Gardens and the Railway Land Local Nature Reserve. It is a widespread species, fairly common where Alders grow, but apparently easily overlooked - like most micro-moths.

The adult is on the wing during two generations each year, during May and again in August. It is very small: about 5mm in length with a wingspan of about 8mm. They have a white face and, if you look carefully in the photograph above, you can see that it has white tips to its antennae. The larvae feed on the inside of an Alder leaf, forming a mine on the underside and causing a mottled appearance on the upperside. This is described well, with photographs, on the British Leafminers website.

On checking Colin Pratt's A Complete History of the Butterflies and Moths of Sussex, P. rajella was first recorded in Sussex sometime just before 1859 by the eminent entomologist H.T. Swainton. That was the last time it was recorded in Lewes. I wonder how Stainton would have felt if he had been told that a gap of 160-odd years would be broken by a chance finding on the inside of someone's office window? Would he have chuckled or would he have shaken his head and mumbled something Latin in a hushed tone?

Most Sussex records of P. rajella are of leaf-mines. There is one record of a larva and, before yesterday, the only adult record was made in 1984, meaning yesterday's record appears to be the first adult seen in Sussex in 32 years.

When one considers the many miles trodden in the dark by Lepidopterists, burdened with heavy equipment, the hours of work dedicated to searching for an elusive species, the disappointment felt trudging back home after a fruitless search, this particular record of a moth which flew into the human world for the first time in more than three decades feels something like cheating. Sometimes serendipitous records such as this are a reward for those barren times.

Of all the windows in all the rooms at Southover House, this little fella had to fly in through mine.
References:

Pratt, C.R.P. 2011. A Complete History of the Butterflies and Moths of Sussex. Volume One. Independently published.

Pratt, C.R.P. 2015. A Complete History of the Butterflies and Moths of Sussex. Volume Four. Independently published.

Sunday 10 April 2016

Early April at Barrow Head

Transect walking season, weeks one and two


It is the second week in April. My good friend David Harris and I have started our annual season of  transect walks around Newhaven's Castle Hill Local Nature Reserve. We will share alternate weeks between now and the end of October, or whichever time of year that there are too few butterflies on the wing to make the walk worthwhile. This is the sixth year that the transect has been walked and it has become a staple of my wildlife year. It is sometimes a tough commitment in high summer, when all the daily demands of life are queuing up impatiently asking for attention, but the transect walk is always a joyous few hours' escape from everything other than what can be seen before you.

David has walked week one; week two is my turn (David odd; Steven even). In week one only a single butterfly was seen: a Small Tortoiseshell (Aglais urticae) on the clifftop at the extreme west of the nature reserve. We have never had a quieter start to the season.

To compensate for the lack of butterflies and moths, David did make an excellent sighting of the Forget-me-not Shieldbug  (Sehirus luctuosus), also along the clifftop but just to the east of the headland known as Barrow Head. This is not a rare insect, but it is not common either and it's a new species added to our site list. It's food-plants (Forget-me-not or Myosotis species within the Borage family) can be found in quite a few places around the reserve and include Early (Myosotis ramosissima) and Field Forget-me-not (M. arvensis), which are just coming into bloom now, as well as the later flowering species Wood (M. sylvatica)  and Changing Forget-me-not (M. discolor). If luck is with you, you might be fortunate enough to see the small black bug crawling on the ground around the plant or perhaps basking on a leaf.

I have just completed the week two walk around Castle Hill. I am out early because the early morning sun is forecast to be replaced with cloud from late morning onwards. I have seen only one butterfly: a Peacock (Aglais io), on the sheltered glade on the north slope of the reserve. Other insects of interest seen included quite a few Dark-edged Bee-flies (Bombylius major) and an extraordinary number of Buff-tailed Bumblebees (Bombus terrestris) - several hundreds or more all basking in the sun, nestled and half enveloped in grass everywhere along the transect route. It is as though all the bees have been placed under a soporific spell.

As I return to my car, which is parked beneath Barrow Head, I am distracted by an attempted robbery: a lone Raven is visiting each of the many Jackdaw-hollows in the chalk along Barrow Head in search of Jackdaw eggs, like a taxman making house-calls. The Jacks are brave and mob the intruder as it moves systematically from one hole to the next. The Raven visits each hollow not with a short hop but with an exaggerated flycatcher-like loop away from the cliff and back again, tracing a teardrop in the air.

These are both Corvid species, but they are the largest and the smallest and the difference in size is startling. Their evolutionary close kin-ship stands for nothing. The Raven goes calmly about its business and appears to be indifferent to the smaller Jacks as they cartwheel through the air, but the hollows are all empty. It seems the Jacks are still nest-building and have not yet laid their clutch. The Raven perches on the ledge of each, looks monstrously within, pauses for a moment and loops back into the air. With all the house-calls made, the Raven moves away penniless in an eastward direction and the drama is over.

A slab of early morning cloud has drifted off to the east and the spring sun warms my back, while a chilly breeze frisks me from the west, chilly enough to usurp any comfort offered by the sun. As the Jackdaws and Feral Pigeons settle, I climb the slump past them and past Barrow Head on its east side towards a flush of golden flowers which have caught my attention and I find myself suddenly out of the influence of the breeze. Here, it is another day; a hot, calm morning in summer. The heat of the sunlight uninhibited by the breeze is astonishing.

Water-pepper - I think
The flower is Lesser Celandine (Ranunculus ficaria). The starburst flowers open only in sunlight, forming a mirror-mat of gold amidst a nest of heart-shaped green glossy leaves. It is a welcome sight, doubly so because they are the first I have seen on the ground we cleared a few weeks before when we were cutting brambles. It might have grown amongst the thorns in previous years, but it could be a pioneer. This flower, for all its early season beauty, is actually an invasive pest which is blooming amongst the grass in most areas across the reserve. A few steps away is a seasonal pool with what appears to be leaves of Water-pepper (Persicaria hydropiper) reaching up above the surface. It is a plant of winter-wet places. In summer its tresses of pink flowers droop in sorrow towards the parched ground.

Lesser Celandine (Ranunculus ficaria) - growing where recently bramble dominated


As I descend away from the splash of gold and skirt along the base of the cliff a movement to the right catches my eye and I see a basking Adder (Vipera berus) slide towards a clump of long grass with a small hole at its side. As I slowly crouch towards it and rest stone-still, the snake pauses and I am granted a view of the black arrowhead behind its red eyes.

Adders emerge from their underground hibernacula - often a mouse-hole they entered in October-time - at any time from late March or when daytime temperatures climb into double figures. Early mornings and late afternoons are the best times to search for them, when they bask in a sheltered spot, such as this, flattening their bodies against the warm earth, soaking up the sun's energy. This is an essential habit which aids hunting and digestion, especially early and late in the season. The immature male Adder before me will spend the next few weeks feeding mainly on mice or small reptiles such as lizards and slow worms. He'll take all the sun he can find.

This Adder might be the same individual we observed last year. He is not fully grown and I estimate that he is somewhere between two and three years old. Maturity is not reached until four or five years. Adders are fairly slow-growing snakes. He is possibly not mature enough to engage in the violent mating rite sometimes called the dance of the adders, which occurs in April or May. This is a wrestling match fought between males, in which no use of the fangs is made, and in which the winner may mate entwined with a female in a tangle with up to several other males.

Vipera berus - a basking female Adder
Adders are not the indiscriminate biters that some people hold them to be. They are misunderstood and vulnerable, unnecessarily persecuted by humans and predated upon by a number of animals including hedgehogs, birds of prey and crows - including the Jackdaws around the corner of this headland. Their venom is precious to them and they bite only if they are forced to defend. I have given this snake no reason to be fearful and he has paused and rewarded my cautious approach with the gift of a close observation. I back away and leave him to the sun.

The Jackdaws wheel and chatter above me and I return to my car, leaving the birds, bees, Adders and flowers to enjoy the sheltered sunlight.

Thursday 7 April 2016

Secrets of a small rookery, part three: Crow Culture

Wheatfield with crows by Vincent van Gogh (1890), oil on canvas


What is a crow to you, reader? The answer will vary depending on who you are, where you live and the ways in which - and the extent to which - you connect with your environment.

To many people, crows are a noisy, messy, annoying family of birds with unpleasant voices who attack bins and rubbish sacks, steal songbird chicks from nests, steal farmers' crops and generally cause a nuisance. To others they are intelligent creatures, innovative problem-solvers - fascinating to observe and a source of immense pleasure. I am firmly rooted in the latter camp.

In about 1995, while walking along the Ouse riverbank between Newhaven and Piddinghoe in East Sussex, I witnessed a group of several Carrion Crows manoeuvring a square of plywood, which looked like an old drawer-base that had been washed along the river and stranded on the high tide line. One crow wrestled the square of wood down the riverbank and into the water, where it floated. Each crow in turn then flew into the air and attempted to land on the floating wood, not very successfully, and suggesting an appearance of novice surfers, but obviously able to take an idea and put it into practise. This level of enquiry on the part of the crows was remarkable to observe. Whether they were playing or attempting to gain some advantage, perhaps by using the floating wood as a fishing platform, I could not speculate about, but it convinced me that crows are clever birds.

Soler & Møller (1990) demonstrated that Magpies (Pica pica) learnt to detect Great-spotted Cuckoo (Clamator glandarius) eggs when their nests had been parasitised in areas where the two species had coexisted for some time. The ability to detect these eggs was reduced in areas where coexistence was more recent and, where their ranges did not overlap at all, there was no recognition. Magpies had developed the ability to recognise cuckoo eggs through learning experiences and had tweaked their behaviour accordingly. Other victims of brood-parasites, such Reed Warblers (Acrocephalus scirpaceus) and Dunnocks (Prunella modularis), have shown no such recognition of Common Cuckoo (Cuculus canorus) eggs. The New Caledonian Crow (Corvus moneduloides) is a well-documented problem-solver, tool-maker and tool-user (Hunt, 1996). Crows are clever birds and their intelligence has impressed and captured the imagination of the humans in their midst.

To many human cultures crow species are a defining cultural reference: gods or messengers of gods, spiritual beings who may deliver the souls of the dead to the afterlife. They are emblematic, their image having been used in aboriginal art including cave paintings and aboriginal names and costumes, heraldic coats of arms, place names (Rookery Hill, Rookery Way and The Rookery are all about a mile away, as the crow flies, from where these words are being written) and in numerous other creative works. We have exploited crows in our culture and crows have adapted to exploit us too. This entwined relationship can be termed cultural coevolution.

Ravens scavenging a wolf kill-site carcass
Here is an example of cultural coevolution: the automobile is one of the defining images of the American Dream. Perhaps there is an inevitability, therefore, that the American Crow (Corvus brachyrhyncos) has adapted its own culture in response to road vehicles. Traditionally, Ravens (Corvus corax), Magpies (Pica pica) and other corvid species adapted and evolved to scavenge the carcasses of hunted animals which they locate by flying and searching across the landscape, perhaps following packs of wolves or humans to a kill-site. Roadkill could be considered to provide the same opportunity, particularly in areas where kill-sites are less common now than they were in the past, so it is not much of a cultural shift on the American Crow's part to follow roads, which cut like rivers through the landscape, searching for dead deer, rabbit or birds. American Crows have also been observed picking dead insects from the fenders of stationary cars. These behaviours should still be considered as a cultural response; they have been observed in North America (Marzluff & Angell, 2005), but probably also occur wherever crows and humans with cars coexist. In Japan in 1975, Carrion Crows (Corvus corone) were observed at a driving school placing shelled walnuts before the wheels of parked cars so that they would be cracked open as the cars drove over them and away. This behaviour has been adopted by observant crows and has since spread some miles along the Hirose River region (Nihei & Higuchi, 2001).

Further reading provides a wealth of examples which demonstrate the effect that crows have had on European culture, and particularly so on our languages, which will be the subject of part five of this corvine compendium.

I think the relationship between crows and humans, whether it is welcomed, tolerated or despised, dates all the way back through human history, back beyond the 150,000 or so years that Homo sapiens has walked across the world, even back beyond the seven million years since our evolutionary trajectory branched away from our closest extant relatives, Bonobos and Chimpanzees. Crows have been on the wing all this time - they evolved (I think) in the Eocene Epoch about 50 million years ago, although the species we share the world with today are more recent. At the end of the last ice age ten thousand years ago, Hunter-gatherers would doubtless have been in close contact with Ravens, who followed or possibly even led humans along the migration routes towards the great herds of ungulates, where we might have revered the birds, tolerated them or chased them off from a kill. As farming practises spread from the Middle-east westwards across Europe and into Britain about six or seven thousand years ago, we would have put down roots and found ourselves closer to other crow species such as Rooks and Jackdaws, who colonised the fringes of the land cleared by our ancestors and who plundered the insect pests which devoured our ancestor's crops and then helped themselves to the same crops as they ripened.

Four seeds in a hole,

One for the Rook, one for the Crow,

One to rot and one to grow.



During the past few thousand years of civilisation and warfare, battlefields strewn with dead soldiers would have been a happy hunting ground for Ravens, Carrion Crows and Magpies. Survivors who witnessed the battlefield-fallen being pecked and torn apart in a corvine feeding frenzy could be forgiven for holding a fear or awe of those birds whenever their paths crossed.

Gallows-crows
The same crows would have perched upon gibbets and gallows and it is easy to imagine them gathering ahead of a public execution - observant and intelligent birds would learn to recognise the signs, the noise of excitable crowds. The black, ravenous birds would understandably have become symbols of judgement, both human and divine judgement.

The crow or raven might have been the influence of the beak-shaped mask worn by plague-doctors in Europe during the 16th and 17th centuries. The costume of a waxed or leather cloak was topped with a mask and beak. The beak was filled with straw and aromatic herbs and oils - all to filter and protect the plague-doctor from miasma (putrid air), which was considered until modern times to be a vector of disease. Even Florence Nightingale is alleged to have believed in misama theory, but the Nightingale is a different bird altogether. The beaked mask of the plague-doctor is still a chilling sight.

We have shaped crows' culture and they have shaped ours. It is no wonder that crows became symbols of fear, death and perdition. It is via this background that crows and crow-culture have become braided into our language.

Plague Doctor costume

References:

Hunt, Gavin R. 1996. Manufacture and use of hook-tools by New Caledonian Crows. Nature 379: 249-25.

Marzluff, John M. and Angell, Tony. 2005. In the Company of Crows and Ravens. Yale University Press: New Haven.

Nihei, Y. and H. Higuchi. 2001. When and where did crows learn to use automobiles as nutcrackers? Tohoku Psychologica Folia 60: 93-97. 
Soler, M. & Møller, A.P. 1990. Duration of sympatry and coevolution between the great spotted cuckoo and its magpie host. Nature. 343, 748-750. 

Friday 1 April 2016

March in the moth trap

I ran my moth trap on 21 nights during March, slightly up on the average number of nights over the last ten years, which is 17 nights.

Despite starting the month with some wild weather and enduring the ferocity of Storm Katie on the night of 27th, the nights during March were generally quiet and chilly, with a mainly northerly flow to the weather. This is the probable reason for the slightly depressed numbers of moths recorded. March, like the first two months of the year, can be painfully slow on the relatively treeless parts of the Downs where I operate my trap. Species and numbers seen were both below their ten-year averages, with the exception of the March Orthosia stalwarts Common Quaker (Orthosia cerasi) and Hebrew Character (Orthosia gothica), which were about a third higher than usual, but still very low in number compared with many more wooded locations. Early Grey numbers were low, despite an exceptionally early record I made on 4th February, and began to appear only during the final week of the month, which suggests a late emergence locally, along with the two Orthosia species Small Quaker and Powdered Quaker, both of which were absent during the month.

There was a similar pattern to the butterfly sightings, with numbers only starting to improve towards the end of the month as the sunlight strengthened and the winds became milder and lesser in strength. Most Small Tortoiseshells were seen basking around rabbit holes, as is the March norm, but they were beginning to wander on the wing during the last two days of the month. With warmer temperatures forecast next week, we should all see a welcome increase in numbers and species.

Ectoedemia heringella (New Holm Oak Pigmy) dominated my fieldwork efforts. This Nationally Scarce species has now been recorded in 59 locations in Newhaven, Peacehaven, Seaford, Lewes and the villages between.

There was a bonus record of the willowherb-feeding Mompha epilobiella, which was seen during a visit to Charleston Farmhouse within one of the bedrooms. At first sight I thought I was witness to the destruction of the natural fibres making up the fabrics and other textiles on display at the house, but relief came with a closer look - so hold off with the pheromone traps!



Hebrew Character (Orthosia gothica)
Common Quaker (Orthosia cerasi)
Early Grey (Xylocampa areola)


Species summary, March 2016
32 species recorded (10-year average is 25), 150 individual moths and butterflies (10-year average is 186).

125W Robinson trap at home (17 species)
Parsnip Moth (Depressaria heraclei)  2
Common Flat-body (Agonopterix heracliana)  6
Brown-spot Flat-body (Agonopterix alstromeriana)  1
White-shouldered House Moth (Endrosis sarcitrella)  1
Light Brown Apple Moth (Epiphyas postvittana) 6
Common Plume (Emmelina monodactyla)  6
March Moth (Alsophila aescularia)  2
Double-striped Pug (Gymnoscelis rufifasciata)  1
Oak Beauty (Biston strataria)  4
Common Quaker (Orthosia cerasi)  41
Clouded Drab (Orthosia incerta)  2
Twin-spotted Quaker (Orthosia munda)  2
Hebrew Character (Orthosia gothica)  40
Early Grey (Xylocampa areola)  3
Chestnut (Conistra vaccinii)  1
Angle Shades (Phlogophora meticulosa)  2
Silver Y (Autographa gamma)  2

Other garden obs at home (5 species)
Small White (Pieris rapae)  1
Brimstone (Gonepteryx rhamni)  2
Peacock (Aglais io)  1
Oak Eggar (Lasiocampa quercus)  2 larvae
Large Yellow Underwing (Noctua pronuba)  2 larvae


Fieldwork (12 species)
New Holm-oak Pigmy (Ectoedemia heringella)  mines
Golden Pigmy (Stigmella aurella)  mines
Holm-oak Pigmy (Stigmella suberivora)  mines
Bordered Carl (Catoptriche marginea)  mines
Brown Oak Slender (Acrocercops brongniardella)  1 mine
Garden Midget (Phyllonorycter messaniella) mines
Common Flat-body (Agonopterix heracliana)  1
Common Cosmet (Mompha epilobiella)  1 - seen inside Charleston Farmhouse!
Bulrush Cosmet (Limnaecia phragmitella) larval feeding signs on bulrush
Peacock (Aglais io)  4
Small Tortoiseshell (Aglais urticae)  12
Comma (Polygonia c-album)  2