Nature Notes from Hilltop News

Nature Notes

If you enjoy living or visiting the Chilterns you cannot fail to be impressed with the variety of landscape, wildlife and the particular weather it offers be it over the seasons of the year or just on a single day. What's more on any given day, the countryside in which the hilltop villages nestle is often characterised by having its own micro-climate compared to the neighbouring towns and countryside beneath it. This in turn has influenced the composition of local habitats and the occurrence of wildlife.

No one set of eyes, ears and sense of smell can capture the essence of the natural history of the hilltop villages. The following nature notes first published in the Hilltop News are just a simple attempt to reflect on the flora and fauna we enjoy through the seasons.

These articles were previously published in "Hilltop News".

Chris Brown
January 2004

Nature Notes – December 2009

Otherwise obscured or easily overlooked

“Having wandered through woods for several miles, the lane suddenly came to the open, and I found myself on an open escarpment of the Chilterns, a country so familiar...” J.H.B. Peel (1970)

The Chiltern scene at this time of the year confirms that the familiarity with which Peel talks about is not just a singular experience to be enjoyed only in spring or midsummer, such as one might experience in an equatorial rainforest where the seasons are unchanging. The Chilterns may be described for the tourist as verdant woodland and pasture but the winter season affords contrasting views of beige through to brown and at times provides the only chance to see the flora and fauna around us which may be otherwise obscured or easily overlooked.

Take the simple example of birds’ nests. Built to survive the rigours of the weather and to avoid being discovered, they remain largely undisturbed hidden by leaves. With hedges and trees stripped bare this is the only time of the year when the intricacies of design, construction and disguise can be seen. Low down in a bush maybe a wren’s nest, a woven tapestry of leaves, moss and sedge or grass. Higher up, a long-tailed tit’s bottle-shaped dome remains entwined in the blackthorn thicket, held in form by the tension of slender twigs and spiders silk. In contrast, swaying in the highest boughs of the stand of beech trees, are the tatty remains of more haphazard nest-building by rooks and crows. The latter will already be hard at work rebuilding theirs, the former soon to follow their industry.

Mammals of all sizes need to steal some of the shortened daylight hours to forage for food or trap prey and are more likely to break cover and be seen and disinclined to seek cover if disturbed when feeding.

There may be over 900 species of moss in the UK. Perhaps we have over 100 in this part of the Chilterns: all on north-facing surfaces. Somehow overshadowed by the tree canopy they remain all but invisible to our senses for most of the year. Now unhindered by leafy boughs the woodland floor is flooded with bright direct sunlight in December and January. Taking advantage of this, mosses make the most of the next two months with vigorous growth, and replenishing their stores of energy. Within a few days they will transform from the dullest to the brightest shades of green, for this short period the most distinctive feature in an otherwise almost monochromatic wood.

You may not have spotted them straightaway but once encountered, others may come into sight, tucked away in a crevice, maybe a door or window jamb. It seems to be one of those winters when the bumper crop of late-season ladybirds are set on making our houses their temporary quarters. Regardless of the willingness of some of us, their hosts, to tolerate and accommodate them, our centrally-heated homes do not provide the right conditions for these beetles to survive the cold season. In their natural environment they would hibernate right on until at least April, unless spring comes earlier in late March. Inside, the artificial climate will stir them into activity too soon, perhaps as early as mid-January before there is any prey, typically aphids, for them to eat. As a consequence they will starve to death. So for the kinder-hearted amongst you, the best advice is to evict the ladybirds, thereby encouraging them to find an alternative hermitage.

My reference book advises on the use of a pooter, a peculiar device: a Victorian invention still used today by entomologists who suck up small insects via a tube into a specimen jar. I suspect this is not a device you have to hand, in which case a tickling stick in the form of a small brush or cottonbud will disturb the beetles sufficiently to encourage them to relocate to suitable place. A superior hotel for insects can be made from a bundle of foot long, hollowended bamboo sticks. In true "Blue Peter" tradition a wholly satisfactory alternative motel-standard home can be constructed from a plastic lemonade bottle cut top and bottom and the cylinder filled by a length of corrugated cardboard, rolled up and stuffed loose enough for the insects to come and go freely. Ensure that the cardboard is sitting well inside the bottle with none left hanging out. If it gets damp the insects won’t use it. Having encouraged your visitors inside, mount the bottle in a tree or tuck into a south-facing wall, pointing slightly downwards to allow any moisture to drain out.

I end on something off-beat though entirely in keeping with the theme. For a seasonal topic I thought what, at this time of year, might one all too frequently stumble over on a walk around these parts? What frequently lies beneath our feet in some quantity at this time of year? I mean all that glorious mud which reliably confronts us wherever we choose to stroll and, despite our best efforts, returns homeward with us. I am assured that wherever it occurs it is of a unique composition and true reflection of the place in which it lies, comprising not just inorganic minerals but the organic remains of the particular plants that grow nearby and the animals that pass over or through or fall into and get trapped.

It’s the sort of stuff that TV forensic scientist Grissom could pin down within a few metres. So as elsewhere, in this part of the world there is a peculiarly Chiltern ooze within which there will be a high proportion of tree leaves; particularly beech, shards of bracken frond, fruits such as hawthorn and sloe at some stage of disintegration. On top there will be the tracks of muntjac, badger, fox, pheasant, horse or human. However, it is also a living habitat for local invertebrates; worms, beetles and centipedes as well as fungi and bacteria. Now while some of the detritus will have disintegrated or dissolved beyond recognition, it will also contain, trapped in the uppermost layer, this year’s deposits yet to be consumed by those invertebrates or dissolved by fungi. A contemporary fossil if you like. Mud is what Peel describes as a ‘chiaroscuro’ of colours and textures and just another reflection of the Chiltern country so familiar.

As always I welcome comments and questions.

chrisbrown@rayshill.com 758890

Nature Notes – October 2009

A thousand shades of ochre, silver, emerald, smoky brass

Sometimes, when I get stuck for a few words to start these Notes I turn to one of the various emails and articles that come my way, to gain some inspiration, or see what is topical at that moment. So this being one of those times, my attention was grabbed by one email, in particular, which seemed to be a good place to start this month. Spiders! Now the first thing the article said was that when spiders are mentioned you lose half your readers. So, to the 50% of you who are still reading, thanks for staying at least this far. Apparently, one thing you may have in common with fellow readers at this stage is a preference for reading less about ‘the fluffy or cute members of the animal kingdom, bunnies and dolphins’, preferring ‘nature in the raw’.

Anyway, back to the spiders, and in particular the house occupying ones which will have started to make their presence known scurrying along the skirting or emerging cautiously from the fireplace. About now, and like clockwork, London Zoo starts getting calls each year from troubled house-owners who are desperate for advice to rid themselves of extremely hairy, long-legged arachnids which, thanks to David Attenborough or the late Steve Irwin documentaries, they readily, but mistakenly, identify as the deadly tunnel spider: no doubt imported on some exotic Australasian fruit.

It’s not just the hairiness which is exaggerated, the going rate for size is around four inches long! It may feel like some kind of invasion, but this generation of house spiders will have been unseen, uninvited houseguests since they hatched out at the start of the year. They remain discretely out of sight until their last moult is done and, now they are ready to find a mate, are at their most active. Such is their delight in living alongside you, if you manage to corral them into a tumbler and drop them out through the window they have a strong homing instinct and will find their way back in very quickly. On the upside, house spiders are efficient pest controllers ravenously devouring flies, mites and other small insects, equally though they can survive a famine for several months between meals.

As I write this, swallows are tumbling high above frantically feeding on the wing, making the most of the bloom of energy-rich invertebrates and storing up the food reserves for the journey to southern Africa. The aerobatic spectacle is the result of the annual explosion of flying insects and those microscopic cousins of the aforementioned spiders who, despite not having wings, spin silk strands on which they ride the air currents. Periodically, and in ever more increasing numbers, the birds rest up in ordered lines along any convenient wires, conversing loudly. Before electricity and telegraphs what did they use instead? On past years’ evidence, by October they will be on their way. However, more and more sightings of these birds have been reported in southern England during November and even December suggesting a small, but increasing number do not make the marathon 6000 mile journey. This change in habit results from a milder autumn period, which in turn is extending the period during which a larger than previous supply of winged insects is available. It is doubtful though that those which remain behind survive through the winter, but in time we may find our swallows become winter companions.

On the path leading to St Laurence’s Church I came across a newly established patch of liverworts where the holly had been cut back. In the wild they must be one of the most overlooked groups of plants, while in our gardens they are frequently the subject of complete annihilation. In past times these very primitive organisms would have been collected, dried and used, as their name suggests, as a cure for a range of diseases attributed to the liver. This is because the simple, flat emerald green ‘thallus’, which comprises the whole plant, is liver-shaped. The Chilterns may not be one of their prime habitats but they are still prolific and enjoy any damp, dappled shaded woodland edge or perhaps a newly created clearing where a tree may have fallen. Their success lies in being able to invade quickly virgin territory, creating an overlapping, scaly green carpet across the unoccupied bark, which then develops its own moist microclimate: the perfect habitat for centipedes, beetles and mites. I know greenkeepers and nurserymen consider them a nuisance and will eradicate them, but in your garden they will provide an important part of your local ecosystem, a source of invertebrates for small mammals and birds, like wrens, goldcrests and treecreepers.

I always enjoy exploring the interconnections between natural and local history. Once such example links our autumn hedgerows with the Second World War, which started sixty years ago last September. At the outbreak of war, there were food shortages. The impact of rationing on diets and the Nation’s health resulted in cases of rickets and scurvy. A campaign initiated right here in Buckland Common by Claire Loewenfeld, a nutritionist, to promote the collection and processing of hedgerow fruits into syrups and preserves to supplement the diets of children with Vitamin C was enthusiastically taken up by the Government of the day, who distributed instructions and recipes to hospitals and schools. Top of the list of beneficial fruit were rosehips, which had the highest concentration of Vitamin C. I am sure many can recall, both during and after the War, children being given the bright red sweet rosehip syrup on rice pudding or semolina. Claire also encouraged the use of other hedgerow fruit including blackberries, elderberries and crab apples. While our diets may not need supplementing in such a vital way we can still enjoy the tastes of the hedges, as well as their autumn colours. Others waiting to enjoy the low hanging fruit will be badgers and this year’s new foxes set free from the security of the vixen, while redwings and thrushes, incoming from the north, will gorge on haws and sloes.

I conclude with a few words from a poem written some 170 years ago, which could describe our autumn scene.

"Leaves of all textures that a leaf
could be: palm, fluff, prickle, matte and plume;
bobbled; shaggy plush. A thousand shades
of ochre, silver, emerald, smoky brass..."

They appear in a new book, "Darwin: A Life in Poems", written by the naturalist, both aboard the Beagle and later. This new book coincides with the 150 anniversary, in November this year, of Darwin’s On the Origin of the Species, and might make a worthy Christmas present for someone interested in natural history and poetry.

That’s all this time. As always your observations and questions are welcome.

chrisbrown@rayshill.com 758890

Nature Notes – August 2009

September sights and sounds; spangling, semaphore, sheaves, shucks and swallows

The weather conditions in North Africa are not my usual starting point I admit. However, the wet winter season in Morocco has provided us with a ‘once in a decade’ display of spangling colour. Painted Lady butterflies are not a resident species in the UK; well at least they’re not for the present anyway. Each year we rely on the northern migration of this distinctive butterfly. It is one of the most widespread and well-travelled butterfly tribes around the globe and is related to another migrant, the Red Admiral. Both belong to a genus called Vanessa, the girl’s name which had been coined by Jonathan Swift around 1700.

Anyway, the unusually heavy rainfall in February caused a verdant covering of food-plant in the Atlas Mountains which in turn supported an abnormally large herd of rapacious caterpillars. Emerging a month later from bejewelled chrysalises, the adults departed northwards to France, Spain and Portugal. A second generation left from there northwards. This year, rather than just tens-of-thousands, up to a million or more arrived across the UK. They have been reported as far north as the remoter Scottish Islands and although they prefer open ground they have been plentiful in the more secluded parts of the Chilterns.

In July these generally non-gregarious caterpillars - which are black/grey spiky with a pale cream stripe along each flank (Peacock butterfly larva is a glossy black) - could be found feeding on thistle and nettle. By the time this imago edition of HTN emerges through your letterbox, the British-born generation of Moorish imagoes should also be about to emerge too. So keep an eye out for this large showy butterfly with its characteristic speedy corkscrew flight pattern.

This UK-born generation do not breed here but disappear and there is debate as to their next destination. Although it has been suggested they head southwards again, there’s no confirmation of the theory that they actually return safely back in North Africa. Lepidopterists are hoping to crack this mystery later this year.

This mystery has a parallel with one which puzzled naturalists over 200 years ago. Then there was a theory about where swallows went in winter. The collective view was that they buried themselves in muddy banks until the spring. Today there is no doubt where swallows go in winter. On warm September evenings they can be seen feeding up on the clouds of insects drifting on the thermals and at dusk congressing as they masse together on overhead wires ahead of their synchronised departure for southern Africa.

A year or so back I commented on the absence of lapwings from our fields in more recent times. This year there have been sightings in an arable field in Heath End and I was also lucky enough, while walking the parish boundary, to see a pair performing a haphazard display, from which they get their name, and aimed at distracting would-be predators from finding their chick(s). Their black and white wings seemingly using a unique semaphore to beat out their message. These were a welcome sight as the lapwing is one indicator of how well or otherwise the local wildlife is faring.

We tend to associate owls with the hours between twilight and dawn and conversely not birds ‘of the day’. Tawny owls break this rule. Fledgling tawnies leave the nest early, after five weeks and far too early perhaps, as they then hang around perched on branches in nearby trees for up to three months, relying on their parents to feed them. I think this is akin to serving a kind of apprenticeship whereby the youngsters supposedly are learning how to lay up motionless and unnoticed during the day. However, like all young children, they crave attention and are given to break cover with spontaneous outbursts along the lines of “Keewik” in the middle of the day. Once heard, look out for a gawky-looking fluff ball trying feebly to appear inconspicuous.

To be honest, being a scientist, my appreciation of our English poets had until now sadly not stretched as far as John Drinkwater, whose works were influenced both by his childhood in the Warwickshire countryside and the later horrors of the First World War. I happened across the following poem, called September, which not only reflects these influences and the time of year but is of particular relevance for another unexpected reason. The verses are believed to have been inspired by the countryside around here, experienced during a short visit in 1915/6. But that’s a story I will save for another time, wearing my local rather than natural history hat on!

Wind and the robin’s note to-day
Have heard of autumn and betray
The green long reign of summer.
The rust is falling on the leaves,
September stands beside the sheaves,
The new, the happy comer.
Not sad my season of the red
And russet orchards gaily spread
From Cholesbury to Cooming,
Nor sad when twilit valley trees
Are ships becalmed on misty seas,
And beetles go abooming.
Now soon shall come the morning crowds
Of starlings, soon the coloured clouds
From oak and ash and willow,
And soon the thorn and briar shall be
Rich in their crimson livery,
In scarlet and in yellow.

Almost 100 years on, many of these September sights (and sounds) around our villages have changed. There are but a few remnants of those ‘russet orchards’ and the image of sheaves is an even more distant memory. Although these elements of Drinkwater’s rural idyll may have disappeared, the autumnal woodland vista and hedgerows described in his third verse still remain very much part of our September scene today, except where they have been replaced by a monoculture of sterile trees.

So perhaps while out one late September day you’ll catch that first glimpse of this year’s ‘clouds’ and realise the timelessness of that view. Meanwhile, there’s also that distinctive crunch underfoot as you walk on the remains of nutshells, beneath a hazelnut tree. Those discarded by squirrels have been splintered in their jaws. Others more intact have a circular hole and teethmarks, having been gnawed through by wood or yellow-necked mice. Amongst the discarded shucks may also be some shells with a tiny circular hole bored in them. This is the work of a third consumer, the nut weevil. One egg is laid by the adult beetle when the shell was small and soft. The larva feeds on the growing nut and, having drilled its way out, continues the journey to adulthood over-wintering under an insulated blanket of leaves.

Thinking of entering a photo in this year’s Hort Soc Show? Some well-positioned over-ripe fruit, such as bananas or plums is an excellent way to attract those large butterflies to the garden and get them to keep still while you photograph them. Happy snapping!

Thanks for the questions and sightings since last time, keep them coming.

chrisbrown@rayshill.com 758890

Nature Notes – June 2009

Socialising - ‘Whilst many a mingled swarthy crowd – rook, crow, and jackdaw – noising loud’

Weathewise, June is the month by which we judge how good our summers are. The rare occurrence of a ‘flaming June’ somehow dictates our impression of the season as a whole. Take 1976, which we oft quote as the benchmark on which all summers are to be judged. It was characterised by an all but perfect June. True, July and August were also sunny but that is not so unusual. My conclusion is that it’s the length of the summer season that stands out in our memories not the occurrence of scorching hot days. So what about this year? Although the Met Office has announced it will be a ‘good summer’, folklore contradicts this with the first cuckoo late announcing its arrival this year (25 April). The only other prediction I will make is that rain will not interrupt play on Centre Court this year!

I was the witness at a wedding a month or two back. Not a wedding I had been invited to and not one involving just a single couple but one with many, many participants. It was a noisy affair but there were no humans involved. It was a ‘crows’ wedding’ but there were no crows involved. Instead, each day from late January for several weeks, there were normally over a hundred rooks flying in tight formation, stalling and stumbling. Why is a conflagration of rooks assigned to crows? Rooks and crows are closely related of course and at a short distance both birds look black but rooks have shiny feathers which in sunlight have an ‘oil-on-water sheen’ of blues, bronzes, purples and mauves. So what is going on at such ‘weddings’? Rooks are the most intelligent and sociable birds of the ‘corvid’ family (rooks and crows, etc) while crows lead a mainly solitary existence.

Maintaining good relations in a crowded community necessitates order, customs and conventions. Rooks achieve this by having rules reinforced by a complex vocabulary; some say up to 30 distinct calls. Younger birds joined in to learn the ropes and practise these elaborate flights ultimately aimed at establishing pairings and hierarchies in the rookery. As the days went by many couples cemented a relationship by synchronising their displays. Victorian writers did not try and distinguish rooks from crows, both of which were imbued with age old affiliations with death and disease and were equally blamed for their destructive abilities and scourge of arable land. Rooks in particular outnumbered crows by a hundred to one, so it remains a bit of a mystery why we have ‘scare crows’ and not ‘scare rooks’. We may describe distances in terms of ‘as the crow flies’ yet it is the rooks in their hundreds, rather than crows, that are known for long, straight flights up to 25 miles returning to their roosts. Much like a rook in a ploughed field, I unearthed this tasty morsel, part of a longer poem about the month of January by the 18th Century poet John Clare, which paints for us a still relevant picture:-

Whilst many a mingled swarthy crowd –
rook, crow, and jackdaw – noising loud,
Fly to and fro to dreary fen,
Dull winter‘s weary flight again;
They flop on heavy wings away
As soon as morning wakens grey,
And, when the sun sets round and red,
Return to naked woods and bed.

One interesting find, summing up the love-hate relationship with the rook, was an account of how colonists to New Zealand in 1874 took rooks with them. Some writers, somewhat romantically, have said this was to remind the émigrés of the ‘Old Country’. Not at all, despite their lessthan- harmonious relationship with man, they were seen as ideal pest controllers to deal with insect infestations prevalent in the South Island. Rook populations may have fallen in the UK but are on the increase down under and there are serious concerns they will become a major pest in their own right in the North Island. Another reminder of animals living in an unusual association with humans came from a recent conversation about the arrival on someone’s doorstep of some wild but highly sociable bees, living happily in the crevices beneath the brickwork - a source of neither damage nor danger. Bees are the most highly developed of all insects. Although the colonies of honey bees may seem to be the ‘bee’s knees’, these housesitter bees are in fact the top of the beepyramid. These bees have developed a specialised trade, wood-boring or leaf-cutting for example. Many of them have consequently sacrificed their ability to bite or sting. So to insure their progeny are protected against predation, they live as individuals but in a loose, but sociable community preserving their individuality but adopting a level of give and take with their neighbours. These bees are in fact the most ‘socialised’ of all bee societies, proving the motto ‘Good fences make good neighbours’. The next group of bees and the largest of all are in fact strictly solitary, shunning publicity. Some are even aggressive towards their own kind and prime candidates for a bee ASBO for their persistent unsociability. Honey bees represent the third way.

A highly ordered, sociable community sacrificing individuality for an impressive organisation of labour, comprising foragers, defenders and egg producers (queens and drones) all locked together by an advanced form of communication. Man has harnessed this community living to his own ends, exploiting their industry as pollinators and harvesting the fruit of their labours. A few thousand years of intensive bee husbandry may be having disastrous consequences. Colony Collapse Disorder is the name coined for the yet-to-be- determined cause for rapid decline in bee communities right around the world. Some of the possible reasons for the declining numbers could be a bee plague, pesticides, or malnutrition. If the commercial bee community were to collapse totally within as little as three seasons, fruit and vegetable food production could have all but ceased. The consequences for food production would be devastating on the human population. I don’t normally recommend a walk amongst the nettles but if the harsh winter has not taken too heavy a toll a third brief example of sociability to look out for are the colonies of small tortoiseshell, peacock or red admiral caterpillars clustered tightly on the freshest leaves. Safety in numbers and co-ordinated reactions to predatory wasps protect the vulnerable larvae and ensure a healthy population of butterflies to socialise in your garden or up and down the hedgerow.

Comments and questions as usual to chrisbrown@ rayshill.com, 758890.

Nature Notes – April 2009

In celebration of the beech!

If the Chiltern Hills has but one signature feature it is the beechwoods. The topography, height and overall poorer fertility of the Chiltern soil has set apart this upland area from other similar ones in southern Britain, such as the Cotswolds, with their rich sheep pastures, or the Oxfordshire and Wiltshire Downs with their sheep folds.

The history of the Chiltern beechwoods is a long one but is cut short here. The last Ice Age sculptured the Chilterns as we see them today. It took until around 8000 years ago, 2000 more years than oak, for mature beech forests to emerge, spawned from pollen blown across the joined-up continental land mass soon to be split by the English Channel. Since then, there have been successive clearance and envelopment by the ancient Wildwoods before being finally ‘tamed’ by axe-wielding Stone Age man around 2-3000 years ago. Without continuous human intervention, these hills would not have the patchwork of managed woodlands, open pasture or arable land we have inherited today. Instead, a mixture of wildwood or impenetrable scrub would have persisted until probably the 16th century and the typical Chiltern villages we live in today would either never have emerged or would not have uniquely developed around or along open common land as they have.

Unlike today, in medieval times a stand of beeches would not have stretched half way to the sky. Instead, trees may have been pollarded or coppiced and if allowed to grow upwards at all would certainly not have been left intact into late middle age or allowed to grow lanky trunks topped out by a broad tree canopy. If oak provided the early settlers to this hilltop region with building materials, beech supplied the energy source domestically and industrially (for smelting iron). From the 16th century, beech’s value as firewood was such that it could be felled and profitably transported from the Chilterns by barge to London.

The next dramatic change came in the 17th century when the first plantations of beech appeared in the Chilterns to support the demand for wooden furniture. Writers of the time, such as Gilbert White, were able to describe both the gnarled and unblemished barked versions of beech growing alongside each other, debating in letters to each other their preferences either for ‘smooth rind’ or ‘knobbed and studded’ versions.

Wood pasture, an almost forgotten farming method these days, was an essential part of this overall woodland management, right through from the early middle-ages, with animals let loose to graze in the autumn off the beech mast. A wood was valued and taxed according to its ‘hidage’ which equated to the number of swine or other domesticated animals that could be supported therein. Look out for clues remaining today of this historic woodland use, such as banks and ditches on wood edges: some still with the remains of coppice and hedging which was once regularly maintained to pen in the grazing animals.

Stepping back and thinking how a woodland was (and is) used also unlocks the key to the wildlife that has been attracted and sustained historically. For example, the robin has always been an opportunist bird. The use of woodland to turn out pigs or forests to sustain wild boar for hunting led to the robin following the swine around, even perching on its back whilst the animal turned the soil in search of roots and bulbs but also unearthing worms and insects for the bird. Fallow deer were introduced by the Romans for hunting and would have been penned in certain areas. Pheasants have been introduced to our woodlands several times and eventually led to the elimination of polecat and martens. Beaver were commonplace until the middle ages when their activities came fatally into conflict with man. Even red squirrels were introduced to hardwoods in the middle ages and were prized for their fur. Their natural habitat were the coniferous forests where they have since retreated: following introduction of the grey squirrel from America in the 19th century, which in turn severely damages the bark of beech trees. Both Muntjac and Glis glis have similar dark histories.

The demise of oak trees and coppiced beech woods, replaced by plantations of smooth-barked beech, has also eliminated many species of moss, liverwort and lichen from the beech woodland scene. The close canopy has starved the woodland floor of light but this has provided an ideal habitat for the early flowering bluebells which so uplifts the spirit each Spring.

With the timber industry no longer supporting the management of woodland resources, protection of beechwoods as Chiltern heritage is important. Conservation organsations (eg the NT) and local people purchasing a woodland at risk from exploitation, are vital for the protection of local woodlands. But there are other risks too. In an ancient woodland, a healthy beech tree might live up to 250 years. Plantation stands of beech now well over 100 years of age are already well past their ‘fell-by’ dates. Hitherto, the trees would have been cleared and replanted after 40 to 50 years. Grown close together on shallow, well drained soils or on hillsides, many are unlikely to survive into old age. On a walk in the woods today you are quite likely to come across an upended tree. The clues to its demise are the overstretched shank (trunk) which has grown fast and spindly as it struggled against its neighbours for light. A second clue is the huge haunches or plates which the tree has been forced to enlarge to buttress the trunk at ground level. Eventually, either unable to support its own weight or, as average annual temperatures increase and the water table falls, becoming ‘stressed’ through not being able to draw sufficient nutrient, it will all the more likely succumb to a gale. In their lingering death and afterwards they provide more sustenance to flora (fungi and bacteria) and fauna (beetles, wood lice and millipedes) than perhaps they ever did in life.

The latest threat to our oaks and beeches, reported in the last 12 months, is from a fungal disease spread via rhododendrons, which are frequent escapees into woodland from parks and estates, including our own local invasion in Drayton Woods. There are plans being prepared nationally to remove rhododendrons in such locations to stem the increase in sudden death of wood and parkland beech and oak.

Victorians viewed beeches as elegant landscape trees: ornaments to show off an estate’s features across open countryside. Elegant tree cathedrals sprang up. Beeches were planted to adorn ancient landmarks such as our own Cholesbury Hillfort. Sadly, as all these trees were planted at once, there is no succession and a walk around the ramparts will reveal time is already taking its toll. A visitor returning in less than 30 years will no doubt do so to a very different scene. So get out there and enjoy the beechwoods and the wildlife therein while you can. They may not be around for much longer!

No weather notes this time by the way. There was just far too much of it in February: making no further mention seems the decent thing to do! Look forward to questions and comments as always.

chrisbrown@rayshill.com

Nature Notes – February 2009

Darwin’s legacy – if eaten, beetles can leave a bitter taste in the mouth

A cold start to the year with Chesham and Benson in Oxfordshire sharing the National honours on the night of 6th January. With snow on the ground, temperatures fell to minus 11°C. Locally, I recorded –11.8°C that night. The outlook for the rest of the winter season is for slightly warmer and dryer conditions than typical for this time of year.

February 12th marks the 200th anniversary of Charles Darwin’s birth. He was one of the foremost scientists of the 19th century, who demonstrated how all species of life evolved from common ancestors by the process he called natural selection: a discovery that continues to have a profound impact on scientific thinking to this day. Although this is what he is principally remembered for, his inquisitive mind not only addressed this fundamental question but he also resolved, or at least laid the groundwork for, answers to many other big questions of the day.

So this Nature Notes picks up on just a few of the less celebrated of Darwin’s discoveries as an observer of nature and his largely unrecognised contribution to agriculture, market gardening and animal husbandry. His nature writing is descriptive, at times poetic, and elsewhere highly amusing. One or two quotes are picked out and included below but his complete works are available online at www.darwin-online.org.uk.

Charles Darwin initially trained to be a Doctor in Edinburgh but found himself not suited to following his father as a country GP, having observed the gruesome autopsy of young girl. This experience also conditioned his lifelong thinking as an anti-vivisectionist who resisted the new fashion of experimenting with live animals. In desperation, his father encouraged him to resume his studies at Cambridge with the aim of becoming a parson. However, instead of theological studies he soon became distracted by his exploits in riding, shooting and fishing.

Luckily for science, this extra-curricular activity led to him submitting letters of his discoveries to learned journals which brought him into contact with, and to the notice of, the most renowned naturalists of the day. This led to an invitation to be the ‘gentleman naturalist’ to accompany Captain Fitzroy on board the survey ship Beagle in 1831. After a five-year voyage of exploration and discovery to South America, including the Galapagos Islands, Australia and South Africa, Darwin returned with thousands of specimens and many new ideas. He took over 20 years to summon up the courage to publish "On the Origin of the Species". The book immediately met with hostility from the established church, however his ideas survived this onslaught and were reinforced by the work of the scientists who followed him. Although his travels provided numerous exotic species, he equally relied upon numerous observations and studies of everyday British wildlife. Here are just a few.

On the earthworm, Darwin elegantly remarked "... it may be doubted if there are any other animals which have played such an important part in the history of the world as these lowly organized creatures". He carried out experiments (in the billiard room of his family home in Downe, Kent), and calculated how materials strewn on the surface found their way deep down in the topsoil. He calculated that, over 10 years, the top two inches would have all been through the gut of worms. We take this subterranean activity for granted today but until Darwin investigated this most essential aspect of soil fertility, it was not understood.

Ever wondered how plants attach themselves to and climb up almost anything so effectively? So did Darwin. Although several had studied this plant behaviour previously, there was no clear understanding of how this occurred and, more importantly, how the different methods of climbing evolved. Darwin studied over a hundred different species grown from seed (including growing hops in his bedroom). His research enabled horticulturalists and market gardeners to develop new varieties of climbing plants: be they clematis, hops or runner beans.

There were many occasions when Darwin was challenged to explain the variety and wonder of the natural world. One such related to wild orchids and how species such as the bee and fly orchids mimic insects in the design of their flowers or as Darwin described them "... the wonderful contrivances of the orchid". During a visit to Torquay in 1861 he noticed how wild orchids were distributed on the cliff side. Consequently, he had an orchid house built and demonstrated how only cross-pollinated orchids produced fertile seeds and the more successful an orchid at attracting insects, the more likely its inherited characteristics would survive. Darwin predicted this effect was down to the transference of genetic material, although it took another 50 years for Darwin’s theory to be proved and the principles of genetics to be developed. Unlike today, breeding of both domestic and exotic fowl and game birds were of popular interest. So it was typical of Darwin’s curiosity with nature in general that he experimented with the breeding of a wide range of varieties. He examined the features of racing pigeons and the colouration of male birds. At times the whole house stank of boiling bones as Darwin sought to determine differences in bone structure of birds bred for racing.

In his latter years Darwin turned his mind to the mysteries of plant movement. He was able to demonstrate that it was not a single entity that controlled plant movement but rather the reaction of a small number of cells just behind the growing tip of the shoot or root which reacted in one way to gravity and in the direct opposite to light. In relation to the root or ‘radicle’ Darwin, in dismissing many of the previous speculations, was close to resolving the mystery when he commented, "It is hardly an exaggeration to say that the tip of the radicle - having the power of directing the movements of the adjoining parts, acts like the brain of one of the lower animals". Once again it took until the 1930s for the final solution to emerge, but it was Darwin’s pioneering work that laid the groundwork for today’s market gardening industry.

To finish, an anecdote from his student days at Cambridge. Darwin describes the perils of being swept along by a beetlecollecting craze, which was fashionable at the time among young gentlemen. "No pursuit at Cambridge was followed with nearly so much eagerness or gave me so much pleasure as collecting beetles. It was the mere passion for collecting, for I did not dissect them and rarely compared their external characters with published descriptions, but got them named anyhow. I will give a proof of my zeal: one day, on tearing off some old bark, I saw two rare beetles and seized one in each hand; then I saw a third and new kind, which I could not bear to lose, so that I popped the one which I held in my right hand into my mouth. Alas it ejected some intensely acrid fluid, which burnt my tongue so that I was forced to spit the beetle out, which was lost, as well as the third one." Itself, an evolutionary tale of sorts, I guess.

chrisbrown@rayshill.com

Nature Notes – December 2008

Three of a kind

So an unexpected cold easterly wind unusually brought freezing rain and snow at the end of October. For any self-respecting wildlife, which was hoping for a prolonged warm spell, that snap has signalled winter is on the way. For migrating birds such as geese and swans, which had been reported delaying their journeys from Scandinavia and beyond, this was sufficient to trigger the packing of bags for the flight south. Last winter was much wetter, warmer and generally unsettled than normal. This year there is expected to be a return to cooler, but slightly dryer conditions. With the water table remaining high, footpaths and bridleways will remain ‘claggy’ and waterlogged.

Three birds which make their presence known, even in the heart of winter, are thrush, great tit and robin. Song thrushes are, in January, one of the few to provide a musical tune at either end of bleaker days. Silent since the summer, Mavis (as it is colloquially known) has a distinctive and mellifluous sound, heard as night turns to day and day to night, singing for up to an hour. Each stanza starts with a sound not unlike “January joy”. Listen out for a particular bird’s unique signature notes which typically will be repeated three times during its repertoire of resonant reprises. Their smaller relative, the mistle thrush, has an altogether more random song, a kind of improvised jazz but more persistent when the weather is inclement for which they have gained the name ‘storm cocks’. Meanwhile, during the short days, great tits launch into song, a triplet of “teacher, teacher, teacher” high up in a barebranched tree. Ironically, during the season of good will, the iconic robin is at its most fierce, defending its territory and chasing off every red-breasted opportunist that dares to make an appearance with an equally strident vibrato call.

Three things to look out for! First, during October/November, this part of the Chilterns has been host to a festival of kites displaying over the open fields at Braziers End and St Leonards. Several sightings have been made, indicating this may continue to be a regular feature in this area. Such mass sightings signify that the birds are supplementing their scavenging with food specially provided for them. Second, winter parasites. How do you get rid of those irritating fleas, ticks and mites from your feathers? In a dry summer, a dust bath can do the trick but in winter what options do you have? Well try out what crows can be seen doing this time of year by using the smoke from chimneys. It can make the eyes water but you should be able to stick it out longer than your unwelcome visitors.

Third, one of the earliest signs that the season is on the turn are the catkins of hazel, in clusters of three, slender and brown at first but early January sees them lighten and turn from pale to brimstone yellow.

Every three years or so we are invaded by a third and most colourful Scandinavian visitor whose sole purpose in visiting seems to be food shopping. Waxwings, with their sleek beige coats overlain with russet brown and with black, yellow and white highlights, are particularly partial to the red and orange berries of cotoneaster, pyracantha and vibernum bushes that adorn supermarket car parks. They start with the north-east coastal outlets but as the weather hardens they move south and west so a cold snap could bring them to a local Tesco, Waitrose or Sainsbury (with the obvious bonus of nectar points!) or to your garden.

A triplet of trees to look up to: Sycamores with the most ungainly arrangement of branches of all our local trees hold the key. The last bunches of bedraggled, winged fruit (keys) hang waiting to be wrenched away and assisted on their journey by just one more gust. Later on, the first pale green buds of the new season are visible, having shed their waxy scales. Also making a show; the more subdued spear-shaped beech buds remain tightly shut but have turned a dark purple and now stand out aside the rusty leaves retained on the tree to protect these more delicate buds. Oak leaves may remain into December in more sheltered spots, if the weather permits. On bright days the leaves appear pink. This is partly due to the remaining pigments gradually being milked of their remaining goodness as the tree withdraws vital elements into its sap. However, the colour is sometimes augmented by disc-shaped protuberances, containing the larval stage of the spangled gall wasp. The tree produces these structures in an attempt to isolate itself from the invader, but provides just the protection the larva needs to mature into an adult.

Three so-called cold-blooded animals, snails, newts and snakes are forced into hibernation from now onwards. It is not just the temperature, but the lack of accessible water when temperatures fall to around zero or below. In the invertebrate world there is often a correlation between speed and longevity. Take the garden snail, which can apparently travel at up to 0.03mph or about 2 ’ 6” per minute. Life expectancy is 10 years in captivity, but two years in the wild. For half that time it will be totally inactive, living within its shell and sealed from the outside world by a bung of mucus called an epiphragm. Before closing the door on winter the snail will have perhaps followed the trail laid down by other snails down an old mouse hole or under a stone.

The three species of newt: smooth, palmate and great-crested, can also live for up to a decade. From late November they hibernate within stone walls, piles of logs or occasionally within the mud of their breeding ponds, until emerging in late February or March. They can travel up to two miles to find a suitable breeding pond.

Each of the three British snakes: grass, smooth and adder hibernate and choose regular sites known as hibernacula. Typical are old rabbit scrapes. Unlike the previous examples, snakes have already found a safe haven by now. The young of grass snakes hatch from eggs in October and immediately seek refuge for the winter. Snakes will only emerge when temperatures have maintained certain levels over a number of days and will quickly seek sunny areas in which to bask and warm up. Much of their hunting is done from water in which they are most agile swimmers.

Three books of a kind for Christmas now: ‘Food for Free’ by Richard Mabey is full of interesting stories, superstition and use by man of plants we can forage for today. ‘Notes From Walnut Tree Farm’ and ‘Wildwood, a Journey Through Trees’ are both by the late Roger Deakin. From a quick browse, they are full of brilliant observations and writings on everyday life in the countryside and the wider world.

That’s all this time, so let me have any observations as always.

chrisbrown@rayshill.com

Nature Notes – October 2008

Nature’s own autumnal aerial display - pioneering flyers, paragliders, hoverers, helicopters and parachutes

Here in this part of the Chilterns in the last week of August and first two of September, we had over 3 inches of rain. A squint at the Met Office website to remind me what had been predicted back in July about the late-summer weather brought amusement when I alighted on the words "... rainfall totals will be near or above the long-term average". Well, whatever that means, does that level of precision provide confidence for the autumn forecast? "... The UK and north-western Europe will probably have below-average amounts of rain this autumn." We shall see!

Whatever the outcome, the reality is that this pattern of relatively cool, wet summers and warmer, dry winters might come to be the norm rather than the exception. We are also told that during high-summer and early autumn we can expect more extreme weather events, sudden and heavy summer downpours or a blistering heat wave or both. At least we can take comfort from being at 650ft plus, away from flooding rivers and with bedrock of porous chalk for insurance too.

To be fair, our weather has always been impossible to forecast. If it were otherwise we would not talk about it whenever we politely exchange a greeting and I would not be rambling on about it here! No surprise then that the media has developed a near obsessive focus on global warming as the simplistic cause of all unusual meteorological happenings. This ignores that the British Isles’ unique maritime position adjacent to the continent of Europe has always given opportunities for extreme or unpredictable weather. In other words, for us the unusual is the usual.

It has always been the case though that even on a busy news day there is almost always a story about ‘environmental disasters’ or impending climatic perils. But while these threats appear to be of increasing frequency, the terminology is not new, becoming a part of common usage back in the 1970s when the fear was not that the planet would over-heat but precisely the opposite, the fear that we were on the edge of a new Ice Age.

Another contemporary phrase ‘nature conservation’ had already ten years’ start and its emergence as an important public issue was denoted in the first set of newstyle commemorative stamps appearing in 1963. Depiction of an everyday crosssection of wildlife was more modest than today and those first stamps included daisies, buttercups, ferns, badgers, bees, field mice, deer, a butterfly and, more surprisingly, a woodpecker and longtailed tit. Compare that list to one from a recent set of stamps, which featured less everyday examples including a pine martin, wildcat, yellow necked mouse and Natterer’s bat: an illustration of how the public’s education and awareness of British wildlife has been enhanced by a long line of TV nature presenters from Johnny Morris to Bill Oddie, via of course, Sir David Attenborough.

October is when summer and winter wildlife meet. In the early part of the month the yellows of hawkweed, upright and fitter look-alikes of their relative the dandelion, and the pinks of willow herb and alien balsam flowers mingle with the reds and purples of autumn fruits, rosehips and sloes. The latter matures right on cue to greet the mass arrival of thrushes, redwings and fieldfares from far ’up North’. The former, not content with enticing eager goldfinches to spread their genetic materials, improve the odds by providing each seed with a pristine parachute to spread far and wide at the whim of air currents. In the hanger, the oak stands out as one of the last to give up its deep-green canopy.

Meanwhile, the crop of beech leaves is ageing more prematurely this year and will display briefly in yellow rather than their signature oranges, bronzes and purples. On windy autumnal days, the leaves on maples and sycamores will fall and expose greybrown winged fruits, whose graceful helical descent has been suggested as a possible inspiration for Leonardo de Vinci’s ‘helicopter’ designs.

Other gyroplane mimics choose this month to lift off. Pesky craneflies emerge from their subterranean caverns to lie in wait for any unsuspecting walker foolish enough to encroach on their territory. Prior to their all-to-brief flights of fancy, craneflies are known as leatherjackets. This alter ego lives but a few inches down, feeding on the roots of turf grass. Despite stories of venomous bites, both the larvae and the adults, which feed on nectar, may be ugly but are totally harmless to us. Spider webs glisten in the dew-soaked grass; their architects having launched themselves on silken strands to glide on undetectable currents of air across open fields.

The surprise of a warm sunny September Saturday morning brings a crop of newly emergent red admirals, drawn to some old fermenting sugar-rich raisins on which they binge close to intoxication bravely ignoring the attention of a marauding hornet. All the old textbooks will tell you red admirals do not survive our harsh winters and come afresh each year as continental migrants, but this is no longer always the case. Alongside the regulars, (brimstones, peacocks and small tortoiseshells), a few will survive our milder winters. This year’s cool and wet summer has dictated probably just two rather than the usual three broods. These late arrivals though are monster-sized versions of their spring ancestors. They need to be titans as endurance flying is essential, paragliding in the cooler air above hedgerows in search of over-ripened blackberries and nectar rich ivy flowers.

Another late display is provided by pheasants, which can be seen locally with plumage variations from bird to bird. The vast majority have the characteristic ‘vicar’s collar’ and blue/bronze plumage denoting they are the descendants of Chinese stock introduced for sport to estates in the 18th century. Occasionally seen are almost black pheasants, again specially bred to impress. These may owe their ancestry to the much earlier introduced Roman and Norman breeds, colloquially known as ‘British pheasants’. All are equally capable of giving the unsuspecting walker a start as they launch themselves haphazardly skywards. Meanwhile, look out for the aerial displays of juvenile rooks, jackdaws and crows. They assemble in larger and larger groups to practise their adolescent aerobatics, much hovering and stalling, accompanied by mutual squawking before breaking out of the congregation in all directions.

So for the next month or so I hope you find time and clement weather to experience the fresh air and open spaces roundabouts, as much as this autumn’s wildlife will be too.

Observations and questions as always to:

chrisbrown@rayshill.com

Nature Notes – August 2008

Stingers, Suckers, Biters and other pesky critters

I set off writing this as Federer and Nadal take an extended rain-break on one of the few wet days for the last month or so but this has most likely set the pattern for the much of the summer to come with both hot, steamy and cloudy, cool days.

A question from a couple of visitors to our area from rural Georgia in the southern United States a month or two back got me thinking about the risks we run when we are out and about in the countryside. Walking down Parrotts Lane, we were forced to cling on to the bank as one of those unnecessarily large 4x4s tentatively negotiated a narrow stretch. As the car pressed by and we moulded ourselves snugly into the grass bank my friends nervously asked if we had any dangerous wildlife they should be aware of at this precise moment. No, I said reassuringly.

However as I said, this got me thinking as to what there is out there in the wilds of the Chilterns, which could trouble us. Well I guess the obvious place to start is with snakes. Of the three British species only the adder is of serious concern. Distinguished by the zig-zag down the back they are not normally aggressive and unless threatened, tend instead to slink away. If unfortunate enough to be bitten (although not normally life-threatening to humans or pets) medical attention is essential. Neither of the other two is venomous. Grass snakes, normally having a yellow or orange neckband, kill their prey by biting; often under water. Meanwhile, the very rarely seen smooth snake is, surprisingly, neither armed with poison nor a fierce bite but a constrictor, tackling the likes of mice and voles.

It is insects and other invertebrates that more often than not bring us grief. They fall into four types. The ‘stingers’ include that unwanted picnic guest, the wasp, which becomes increasingly irritable as the season progresses. The hornet, a close relative of the wasp, certainly packs a punch but despite its reputation steers away from troubling us if we in turn leave it alone. Meanwhile (Hollywood movies aside) bees have to be seriously provoked to retaliate.

The next group of insects are the ‘suckers’. All of these are pests of domestic animals, such as horse flies and midges and are doubly troublesome to us as being also carriers of serious diseases. Only the females bite in order to obtain blood for protein as part of egg production. Nowadays, mosquitoes in Britain no longer carry malaria but one hundred and fifty years ago during Victorian times this was a major cause of death in the Kentish marshes before these areas were drained.

The third group are the ‘biters’, ranging from centipedes that use their front legs to insert poison into the skin, to the water spider that can also inject venom with a painful bite, leaving you with an inflammation similar to a bee sting.

The fourth group are best described as the ‘pesky critters’. Brown-tail moth caterpillars have barbed hairs which when brushed against can cause anything from a mild rash to headaches and nausea. Meanwhile beware of sitting on a mound made by woodland red ants. Do so and you may experience multiple bites followed, if you are unlucky, by stinging, and if you are still around they will spray you with formic acid for good measure. For most of us such attacks result in a relatively mild reaction caused by our bodies producing histamine; but for a few, just a small amount of venom or anticoagulant can cause anaphylactic shock where urgent medical attention is needed.

Dangers are also lurking for us in the world of plants. There are just three contact poisonous plants in Britain. I’ll just mention stinging nettles only in passing. Next on the list has to be giant hogweed that contains a phytotoxin, which reacts when the skin is exposed to sunlight and causes blisters and longer term scarring. The third is only a threat if you fancied a quick dip in one of our ponds. Blue-green algae, which is present in both fresh and seawater will, if confronted when swimming, affect our eyes and provide an all over body rash.

Apart from some over-friendly highland cattle and some inquisitive ostriches, the only large animals I could come up with were the occasional sightings of wild boar! Mind you a regular contributor of interesting local observations (P. Dice) has passed on that there has been a sighting of a very large black cat (of puma-sized proportions) in the area, so keep a good lookout!

Meanwhile as we walked along the lane I learned from my American friend what they had to contend with in the foothills of the Appalachian mountains: ten different lethal snakes, cougars, lynx, wolves and bears. I’ll spare you all the spiders and insects and plants!

So what’s out and about this month? Down in the leaf litter under hedges, pigmy shrews, our smallest mammals, are rushing about in search of beetles etc. They weigh less than four grams (or one penny coin) and females must feed continuously to top up their metabolism as they produce at least five litters per season. Adult toads are on the move. They travel considerable distances in the Spring to find a breeding pool and at this time of year will be found in and around the ponds building back up their strength, stalking their food and using their sticky tongue to snare it, then blinking their eyes to assist the swallowing processes.

Swallows, swifts and martins will be making the most of the billowing clouds of insects wafting on the evening breezes. Last year was a disappointing one for butterflies. The cool wet weather prevented many adults emerging or having sufficient time on the wing to pair-up. So far this year things are looking up with a good supply of early summer ‘flutterbies’ making the right moves. Look out for fast flying day time ‘hummingbird’ and ‘bee’ hawkmoths visiting the flowers in August. They are very fast and look just like their respective names.

Take care driving along the lanes as dusk falls. There is a large number of young muntjac around straying naively onto roads away from the safety afforded by their mothers. Owls are also out hunting to feed their young and frequently sweep low along the high-sided verges, so are also vulnerable. Perhaps a collision with either of these will be the biggest risk you’ll run with the local wildlife, so take care!

Finally in the ‘Recently seen in the Hilltop Villages’ section (Puma’s aside that is). We seem to be a popular place this year for raptors, with more and more sightings of red kites and buzzards, plus some interesting chance observations of some smaller birds of prey engaged in aerial acrobatics over the woods in Hawridge Vale last month: and just before going to press, I have also just had a delightful report of one of this year’s cuckoos being fed by a pair of dunnocks. So as always questions and observations always welcome.

chrisbrown@rayshill.com

Nature Notes – June 2008

Black is the new grey for the shadow-tailed one

I’m not sure if it is just me or have others noticed all our seasons seem mixed up these days? I guess it could be to do with a climate influenced by global warming but then again just as easily the English obsession with the weather. Last year, our summer was much wetter than in recent years (as wet as 1914; a very wet year). This year, although a repeat is not expected, the Met Office tell us we are liable to have some unsettled spells with cool wet springlike days as late as June or July.

The name ‘squirrel’ comes originally from a Greek word meaning ‘that which makes a shade with its tail’. Squirrels are back in the news again for two reasons. Firstly grey squirrels have established themselves in Scotland, territory of the ‘reds’, for the first time and secondly, black squirrels are displacing greys in England. In mainland Europe black and albino variants of red squirrels are quite common but are unusual in Britain, meanwhile albino variants of grey squirrels have been regularly reported, mainly in Essex, Kent, Surrey and Sussex. Between 1876 and 1929, around 30 introductions of American grey squirrels were made into England and Wales although the ones introduced to Woburn Park (Bedfordshire) at the end of the 19th Century are attributed with their subsequent naturalisation in England. ‘Black’ examples of ‘greys’ have until now been limited in number but the situation is changing rapidly in seems. Surveys indicate there are about two million grey squirrels in the UK and between 125 and 150 thousand ‘reds’ the majority of which are in Scotland. However it has been estimated there are at also at least 25,000 black squirrels distributed across the eastern side of England. The ‘black’ is a variant of the common American invader the ‘grey’. When I say black, some are ruddy/brown/black while others are a sleek jet black, the latter offspring of two ruddy adults, two black or combination of both.

But why? Where blacks occur they appear to be dominant over their grey cousin. Genetically they are missing a sequence of DNA. As originally described by Darwin in his theory of Natural Selection for such a mutation to persist it must be giving the black variety an advantage: in this case providing the black with a better immune system or higher levels of testosterone in its blood, which in turn influences the animal’s behaviour. In short they are thought to display more aggressive behaviour than the more placid grey – tell that to a red squirrel at the time the greys were introduced!

The first sighting of the black mutant was in 1912 in Letchworth Hertfordshire, which now has a black squirrel as its town mascot. Since then they have spread out to other parts of Herts and Cambridgeshire where in some villages (e.g. Girton) they represent 50% of all the squirrels present and it is anticipated to move into parts of East Anglia. So are they coming this way? Maybe. The sightings nearest to us have been in Whipsnade and nearby Studham, which is, but a squirrel leap from Ashridge forest. So it is quite possible the odd black shadow-tail is lurking in a beechwood around here. Keep an eye open.

There are around 260 species of bee in the UK. Each year, regular as clockwork, our outhouse plays host to a small but growing colony of wild social bees. The queen that hatched at the end of summer last year and hibernated over winter is first seen in late March/early April, seeking out a suitable venue to lay its eggs. In this case the space behind some pine lap, accessed via a discrete knot-hole. May sees the first activity of this year’s brood of workers. As I write this they are streaming back and forth, decked in the yellow pollen gathered in the rape fields about a mile or so away. By June the hive is at its height of activity as the queen will be in full-swing egg-laying, supported by the drones, which according to a local (female) apiarist, are “just typical of males, hanging around the nest just in case the queen needs servicing!” These small bees are almost silent; there is just a slight hum as you listen close to the entrance. The peace is disturbed though by the low-frequency drone of a larger very black and hairless bumble bee ferreting (can a bee ferret?) back and forth aside the pine boards until it alights, switches off the power and then silently enters via the hive entrance. This methinks may be a cuckoo bumble-bee, one of six varieties we have here. Their life is one of solitude and their habit is parasitic and brutal. They carry no excess baggage so are honed for speed and attack. The mission of these all female agents ‘women in black’, is to enter the hive undetected, kill the queen, lay their own eggs and exit unscathed mimicking the behaviour of the social bees and so avoiding discovery. Meanwhile the ‘midwived-cuckoos’ are looked after by the mesmerised host drones. Not this time though as this cuckoo has been rumbled and makes a speedy retreat from the nest.

Hedgerows are at their very best this time of year. My suggestion this time is to make a bee-line for one near you and dally a little to take the vista in. Hedges are just blooming alive with animals on the make at the moment. The creamywhite of elderflower takes over the baton from hawthorn. Clumps of yellow archangel point to a hedge-line that is all that remains of scrubbed out woodland. A typical hedgerow herb is the pinky-white cuckoo flower (lady’s smock), which is out between May and June in these parts. It’s just one of many given an alternative name by poets or herbalists of old associating them with the arrival, call or departure of the eponymous bird. Others include cuckoo buttons (burdock), cuckoo’s bread and cheese (wood sorrel), cuckoo boots and stockings (bluebell), cuckoo rose (wild daffodil) and cuckoo buds (buttercup) used by Shakespeare in Loves Labours Lost.

Cuckoo, bring your song here!
Warrant, Act and Summons, please,
For Spring to pass along here!
Cuckoo Song - Rudyard Kipling

And finally, I will have to be more careful in the future when asking as I did last time for reports of the first cuckoo as it seems I may be causing a bit of a frenzy around these parts. This year I had both emails and calls over the 12 hours between 15-16 April (a day earlier than last year) announcing arrival of at least one very busy male bird in Hawridge and St Leonards. The males arrive first and fly around calling a lot to try and maintain as large a territory as possible ahead of the females. Interestingly enough, cuckoos are not the only ones on the hunt for bird nests this time of year. Despite having strict vegetarian habits for eleven months of the year, the shadow-tailed one is also partial to a bird’s egg or two about now.

Questions and comments welcome as always.

chrisbrown@rayshill.com

Weather and Nature Notes – April 2008

Gowk, Har and Whin

A very wet start to the year saw nigh on 4 inches of rainfall in January. As I write this, the wind is getting up for a second night this week. Will I finish before the power goes off again? Looking ahead we should not bank on repeat of last Spring’s record temperatures, the warmest since 1914. April will be noticeably cooler than normal although later on in May it will probably make up for a slow start to the growing season. Rainfall will be much as you would expect for the time of year but as the water table remains high there will be a continued chance of surface flooding if we experience a heavy downfall.

It is not immediately obvious but over the first part of this year many thousands of our commonly seen garden birds are on the move, ‘migrating’ back from their seasonal quarters. Each autumn many of the birds in our gardens make themselves scarce. By spreading out along the hedgerows and woodland edges they can feast themselves on energy-rich seeds, nuts or berries whilst taking refuge from the worst of the weather. In recent years this habit has been slowly changing. With the milder winter season and our growing tendency to supplement their diet by putting out food, some varieties of garden birds are staying put. Birds have different ways of feeding in the winter or when food is scarce. Typically goldfinches, specialist nut feeders, linger on the perch and can be seen defending their ‘horde’ (e.g. sunflower and niger seeds) meanwhile, nuthatches and coal tits neither of whom hang around are smash and grab merchants. Then there are the marauding troupes of long-tailed tits that noisily breeze in at 10 to the dozen an as quickly spiral off as though connected by invisible elastic. All these birds have been on the increase in our gardens, in recent years, according to the census numbers reported by the BTO and RSPB. Another conspicuous visitor this winter which has, this year, been reported in these parts has been the brambling. It often congregates with other ground-feeding relatives such as chaffinches, whose numbers like sparrows, have been falling in recent years. So one action that can be taken is to provide a supply of seed in a trough or the like at ground level this will help the ground feeders including enticing some of the larger birds such as pheasants.

It’s the time of year for the Har. Har is another name for the hare and is Old English for grey or old. Old perhaps because the hare looks like it’s a stooping rabbit. Brown hares were brought to Britain with the Romans, possibly for the sport of coursing. (Before this only Mountain hares could be found in moorland Britain). Their sudden arrival in this country and prominence around the festival of Eostre probably accounts for their adoption as mystical creatures in Pagan culture. They were originally animals of the steppes in Asia, which moved into the continental grassland prairies. The clearance of forest and development of arable farming enabled them to spread fast in lowland areas but they cannot survive in the highlands where their cousin still holds sway. The next two months is the best time of year to see hares; they are active over their prolonged breeding season from February to September and despite being night-time feeders they are most visible around now with crops only newly emergent. The “boxing”, for which they are noted is not a territorial battle by males but is instigated by the females repelling over-amorous suitors. Females can raise up to four litters per year, each of two to four young (leverets). Unlike rabbits they do not use burrows but rear their young in scrapes or forms, where they and are particularly vulnerable so they stay motionless all day and only being fed at dusk to avoid detection by predators. Hare populations vary considerably from place to place and season to season, leverets, in particular, being heavily predated by foxes and stoats. They rely on their marbled camouflage to avoid detection and their speed to escape. Although around here their numbers maybe modest, two places I have see them in recent times are the fields at Bellingdon End and those between Hawridge Common and Heath End. Elsewhere, when numbers overrun and due to the damaging impact they can have on cereal crops and young tree saplings they have to be managed as a minor pest.

It’s also the time of year when one listens out for the Gowk. The work Gowk is a Scottish or north English word for one who is an awkward or a foolish person who does not take their responsibilities seriously. In this case we are referring to the cuckoo, well named on account of it leaving parental responsibilities to others. Last year the first call was on 17th April. It is said to be lucky if you hear your first cuckoo when out walking and no such luck if still in bed! Let me know if you hear one around this date this year and what you were up to at the time!.

The hedgerows and commons really come into their own this month. Yellow flowers predominate attracting in particular some of the first bees of the year. Although already making a showing if March is warm, Lesser celandines appear where the ground is wetter. Cowslips like well-drained undisturbed pastures where chalk is not far from the surface. Look out for Common gorse, which is one Old English name that has stuck, as it has also has regional names of furze and whin (as in whinchat a bird which sings from the top of furze bushes). These days its erstwhile usefulness is largely forgotten. Its presence on the Commons are not an accident, as it would have been carefully managed and cherished, as the young shoots are a valuable source of animal fodder, whilst the woody parts make excellent fencing to keep animals in or out or for fires. So any Commoners found abusing their right to collect furze were liable to a heavy fine.

Once again with the bluebells due out in the last week in April there is only one choice for the kind of walk this time of year but plenty different woods to choose from. But beware the first speckled wood butterflies have emerged and are all males. They set up territories along the woodland walks and are prepared to defend their domains ruthlessly!

Please let me have your observations and questions as usual.

chrisbrown@rayshill.com

Weather and Nature Notes – February 2008

Spinning a tale or two about the web of life

Difficult to believe in a year when there was no summer to talk about, but 2007 was the third warmest on record, only edged into bronze place with 1998 in gold and 2005 in silver. Despite this, 2007 also proved to be the wettest so far this decade (circa 33 inches fell locally). Whereas Britain suffered major flooding in 2007 we were lucky to escape most of the deluge in July, which luckily fell mainly elsewhere. In fact this increased rainfall has been a significant feature of the last 18 months or so and has led to a dramatic rise in the local water table, which rose to over 50 feet by April: its highest point since 2001. As the water table has remained high going into 2008 and with the medium-term meterological forecast suggesting a wetter than average first quarter, I anticipate that we may see the seasonal chalk streams and bournes spilling out lower down the ‘vales’ and as in 2001/2 once again putting pressure on Chesham’s flood management.

There are over 640 species of spiders in Britain and 100 of these can be found in our gardens and around a dozen more living amongst us indoors. Early morning dew bedecks the webs of garden spiders. It is only the female who constructs these traps. The male scavenges for food rather than producing these elaborate structures. The webs are built twice, the first time a non-sticky framework, which is tensioned with stout strings. When the second web is spun it starts as a fine spiral on the central section of the web. This is where the spider will await its prey. Meanwhile the outer sections are then re-spun using sticky gummed silk produced by a special gland and entwined by three spinnerets on the spider’s abdomen. The non-sticky strands of the first web are eaten as it goes. To avoid getting tangled, the spider spreads special oil liberally over its legs. Not all spiders produce elaborate webs. Some lay their sticky strands across the grass in a mesh; others produce funnels or ‘spit’ a sticky net at their prey. For the spider this is a web of life, for its prey a web of death!

Cock pheasants are prone to causing a disturbance day or night at the moment as they patrol their territory, ensuring their harem of hen birds are not wandering off. Occasionally, a younger male ‘on the make’ will try and muscle in and this will set-off one or more controlled couplets of clucks. Where the encounter is with a deer, human or predator, rather than a cluck it’s a cacophony. More distinctive though are the wing beats of the defending male as he drives the upstart off. Whereas we hear this as the drumming, it is not so much the noise but a low frequency vibration, too low for our ears, which resonates for several miles around and signals to other contenders to keep away. Other ‘game’ birds such as grouse and quail have their own distinctive signature tunes. Perhaps most unusual is the snipe, a wading bird much persecuted as ‘game’ in earlier years, which I recall hearing as a youngster as its booming sound bombarded my ears causing me some discomfort.

Populations of these game birds are subject to many ups and downs. Typically, this is the result of being both reliant on a reliable and constant supply of invertebrates, grain and grass or in the case of pheasant all of these. On the other hand, healthy populations of ‘game birds’ support many predating animals – fox and stoat, or bird – sparrow hawk, peregrine and jay, or reptile - grass snake, which like the jay, happen also to take eggs. This web of life is complex. So fluctuations in the population of ‘game’ birds have an impact on those above and below them and vice versa.

Early morning - the hour before dawn - the airwaves are the province of blackbirds, chaffinches, starlings and thrushes. Blackbirds having made the running during January although due for a comeback in March, fall silent in February leaving the way clear for Mavis (the thrush) to rehearse any one of over 100 tunes it has in its extended repertoire. Meanwhile, starlings freed of their autumnal murmurings will be heard to whistle as they seek out a cranny (or nook). Chaffinches start hesitantly but when others have had their say are still going strong, finishing with a flourish. The mellow laughter or ‘yaffing’ of green woodpeckers in flight can be heard. The key to breeding success for such birds will be the availability of invertebrates. Warmth encourages the early emergence of sugar-rich flowers such as celandines, the ninepetalled stars bursting through their leaves, garlic, and in these milder days, cow parsley. In early March, there is the annual flourish of blackthorn, the pungent whitewash marching at the double along the lanes from Chesham, Tring and Wendover taking perhaps a fortnight to reach the hilltops. Without this sugar-rush there will not be an explosion of flies and bugs to provide the source of carbohydrate essential if these birds are going to have sufficient energy to propagate. This web of life is fragile. No warmth, no flowers, wet grass means plenty of worms and ground beetles, meanwhile a sharp frost and bug and bird alike are sunk.

On warm March days look out for the sulphur-winged brimstone butterflies emerging from hibernation, normally but not always ahead of small tortoiseshells. Our mild winters now support overwintering red admirals hitherto delayed abroad until the first favourable continental winds. However, a forestalled spring and shortage of suitable nectar-producing flowers will mean fewer eggs are laid and therefore less predation of the food plants. The web of life is selfregulating. So in good years an excess of caterpillars will consume all the food leading to shortages later in the season.

Some of you may have heard Sir David Attenborough last month launching the 2008 Year of the Frog campaign aimed at raising awareness of the fragility of the populations of frogs due to industrialisation, pollution, deforestation, climate change and in particular a newly discovered disease which is affecting certain populations around the world. Frogs are unsurprisingly not at the top of most people’s list of favourite animals. However, without them many pests of our cereal crops such as slugs, or beetle larvae and, further afield, locusts would be uncontrolled. Alongside spraying and inoculation they are the principal control for mosquitoes and the spread of malaria. The campaign is not aimed at changing their celebrity status but is more about raising their importance for conservation purposes and the crucial role they play in the web of life.

So next time you happen on a glistening spider’s web, think about the metaphor it portrays. A delicate inter-connecting weave of plants and animals whose ecology is balanced on thin threads which are easily damaged.

As always I look forward to your questions and comments.

chrisbrown@rayshill.com

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