The three of us walked silently through the fields in unqualified awe of this phenomenal natural undertaking. I had by then lived at Aigas for more than thirty years – thirty years of looking out over those fields. I had occasionally seen a few spiders ballooning; sometimes landing on me or their threads tickling my face, and I had marvelled at it, but never before had I witnessed anything like this uncountable host of such biblical proportions.
Ian and Morag were awestruck too. We had no words for it beyond the occasional fatuous exclamation of ‘Good God!’ or ‘Look at this lot coming now!’ Ian had brought his camera and was busy capturing macro-images of the tiny spiders reversing up to the tip of the grasses, gracefully balancing into the tiptoe position and the silk beginning to emerge from their tail ends. Morag and I stood and gazed out over the fields, over the valley.
It’s impossible to estimate the numbers of individual sails we saw that morning. There were millions, perhaps hundreds of millions, maybe billions – I have no idea and I cannot imagine a mechanism for counting them. But I do know that each individual thread was virtually invisible to the human eye at a distance of ten yards. From my study window to a central position above the valley fields is easily two hundred yards, three hundred – even more. For the sails to be so numerous and so thick as to be clearly visible, like a cloud of mist, from considerable range means there must have been countless millions of spiders all ballooning at the same moment, not just in our fields, but many other fields up and down the valley, the air so thick with them that they blotted out the view.
After a while I returned to my study and my desk. But my brain had not been able to assimilate properly what I had just seen. I found that I had to get up over and over again to watch this spider float-past still massing across my gaze. It went on for two and a half hours. When I could no longer see the gossamer clouds I went back down to the field and searched. I couldn’t find a single spider. They had all gone.
So why? And what mysterious signal had triggered this mass exodus of spiderlings across the landscape? The tiny spiders we saw were immature Linyphiid money spiders, of the common genera Lepthyphantes and Erigone, both given to the practice of ballooning dispersal. They must also have been hard-wired to recognise precisely the best conditions for this pivotal moment in their tiny new lives. It is inconceivable that so many millions could have communicated with each other over such a huge area, but if the atmospheric pressure, the wind, the humidity and the temperature all came together at the peak moment in the year for Linyphiid money spider dispersal, delivering a universal ‘Yes, go for it!’ signal to every spider of the right genus and species throughout the valley fields, then it seems likely that meteorology alone could have been the trigger.
Using fans and wind tunnels, scientists have tested air flow as the trigger in laboratory conditions. Results are pretty conclusive. It is consistent air flow that matters most. The correct level and duration of air flow, at the right temperature, stimulated the initial climbing behaviour up the stem of the take-off plant. There was then a pause while the spiders seemed to be assessing the reliability of the air flow before they started spinning silk. After a few minutes, apparently convinced, they assumed the tiptoe position and commenced spinning especially fine threads, sometimes single, sometimes multiple.
Once they are up and away they are totally out of control, literally wafted on the winds of chance. Many will perish; they will land in water and drown, be gobbled by birds, get blown out to sea or into wholly unsuitable habitats. But others, perhaps even the majority, will find suitable pastures new. Some will travel only a few yards, some a mile or two, others may get swirled up into the jet stream and carried round the globe, a fact remarkably illustrated by one tiny South Atlantic island.
The devastating 1961 volcanic eruption of Queen Mary’s Peak on the island of Tristan da Cunha caused the evacuation of the entire population of 230 people. The scalding lava flows wiped out all existing life across huge swathes of the island, caused the sea to boil and rendered the land a fiercely hostile desert of caustic ash. When, after several months of cooling, a scientific expedition arrived to assess the damage they were astonished to find that South American Linyphiid spiders had arrived on the wind and re-colonised the island. The Argentinian coast is 2088 miles away. They had ballooned in on the turbulent winds of hopeless odds, dropping out of the sky to find themselves accidental first-time colonists. In order for those random few to have made it, millions more must have perished in the ocean.
I have no idea where my spiders landed. Some, I’m sure, achieved only the end of the field or the line of trees at its margin, but that wasn’t what mattered to me. It was the overwhelming spectacle of their massed legions, the unassailable conviction in their singular marches up the stems, the unswerving certainty of their resolve, their uninstructed dedication to the species’ cause and the astonishing hordes of their silken outpourings clotting the sky that gripped me that day. A day never forgotten.
18
Gods of the Morning
Most satisfying is the robin . . . its song is a fixture of this time of the day. It bubbles up out of the black mass of our hedge like a tiny breeze-ruffled brook of notes. It’s the first god of the morning.
Crow Country, Mark Cocker
There is blood on the snow
and a trickle of rowan berry juice
on his bib where the pine marten
stands for a moment like a man.
‘The Pine Marten’, David Wheatley
We have arrived at 15 September and the cycle of our year is almost complete. Today dawned calm, chill but not cold, and as fresh on the cheeks as a splash of cologne. We love this intermezzo in the year’s turning. It’s pivotal, a point around which everything out there knows it’s about to change but drags its feet as if it doesn’t want to. It’s as though the month is orchestrated by a conductor who can’t make up his mind. The weather oscillates, bearing autumn’s name yet still trailing a waning summer’s coat. Even the air seems to be lingering.
Yesterday the sun beamed its failing warmth across us with a radiant smile. When I was sitting still in the garden after lunch with my eyes closed, it could easily have been August. Bumble bees hummed and a robin sang deliciously from a cherry tree. Peacock and red admiral butterflies still fluttered through the herbaceous borders and in the shade of the trees midges danced through caves of cool air.
These fleeting moments of the year are among those I cherish most. Before the equinoctial gales sweep in from the west and night temperatures crash to ground frosts that sugar the morning lawns, there are great riches to celebrate and some to avoid. The mysterious world of fungus shows its hand. All year mycelium has been invisibly insinuating its dark authority underground; suddenly it decides to spread its spores. Fruiting bodies emerge from nowhere, bursting out of tree trunks or levering the earth aside mole-like to surface and spread their delicate gills and pores. An hour’s fungal foray garners an astonishing array of colours, textures, shapes, varieties and possibilities. The inverted apricot umbrellas of chanterelles, Cantharellus cibarius, and sticky brown-capped penny buns or ceps, Boletus edulis, are common and mouthwateringly abundant.
Eugenia, our creatively inspired field centre cook, heads off into the birch woods with a trug over her arm and a rapturous smile herding her cheeks up under twinkling eyes. In her native Poland, edible fungus is a cultural imperative greedily awaited every autumn. This is her moment. She will arrive back with her trug brimming over with chanterelles, ceps and field mushrooms. She will sauté them in butter and deliver up steaming bowlfuls, succulent, aromatic and utterly delicious. They will appear in soups, stews, quiches, omelettes and, most delectably, in scrambled eggs. Those she doesn’t use fresh she will dry or bottle in vinegar, hoarding them on a top shelf for the dark days of winter. In the woods and fields at Aigas, we have recorded many hundreds of species of this most arcane form of life.
Not all are so benevolent. Many are parasites, eventually killing
off their tree hosts, like the dreaded Armillaria mellea, honey fungus, which gives off a deceptively benign honey aroma, and its equally sinister sister species A. ostoyae, both of which enhance their menacing presence with radioactive bootlace-like mycelium, which rots the roots of mature trees so that the tree topples in a gale, often snapping off at ground level. What had at one moment appeared to be a tall, healthy tree in the prime of life is suddenly brought crashing to the ground without any warning. When this first happened to a gnarled old rowan tree in the middle of the lawn, I went out on an overcast night and found the exposed black boot-laces of mycelium glowing in the dark with a dull bioluminescence and the scent of honey floating on the cool night air. They seemed to me to be gloating, smugly pleased with the grim and devastating consequences of their deviousness, like a Machiavellian politician of the Renaissance. It would not have surprised me if I had heard a hollow, mocking laugh.
Examining its work in the light of day, I found that I could push my finger into what should have been solid ligneous root tissue – some of the strongest wood in a tree – now reduced to mush. It has accounted for many fine trees around us, rowans, birches, red oaks, sycamores and cherries. I don’t know it’s there until the mushrooms appear, clusters of bulging, ginger-brown caps thrusting upwards and outwards from the base of the doomed trunk, shoving each other aside in their haste to expand their gills and spread their mellifluous infection of invisible, dust-like airborne spores.
Others are not so devious, but nonetheless devastatingly poisonous if eaten. Amanita virosa, the aptly named ‘destroying angel’, pops its pretty little head up in the shade of its beech tree hosts every autumn, all smiles and innocence, delicately appealing, pure white and chastely veiled like a bride; almost worse, at a cursory glance, when it first appears it is scarily like a field mushroom. But, beware, it is deadly. Mycologists say don’t even put it in the same basket with edible mushrooms and wash your hands after touching it. Ingestion of even a small part of one will annihilate your liver and kidneys in a matter of hours. Rapid organ transplant is the only way of surviving the virulent α- and β-amanatin toxins.
There are others out there, too: the attractively red-capped, white-spotted fly agaric, Amanita muscaria, sometimes known as the Enid Blyton toadstool, grows everywhere here, although its poison is far less threatening. Its toxin, muscarine, is hallucinogenic, but don’t try it. It can make you very, very ill. And there is the inoffensive-looking Cortinarius rubellus, the lethal webcap, a mushroom-sized cinnamon-coloured toadstool with a Chinese coolie’s hat that has recently devastated a family not very many miles away from us here. They await kidney transplants and are lucky to be alive.
Eugenia is also to be seen emerging from a thicket or from under a hedge, hair in knots and tangles as wild as the undergrowth, where she has been collecting nature’s free fruits. Wild raspberries, blackberries, elderberries and the tiny little flavour-rich wild strawberries all find their way into her trug, then into her jams, her purées and sauces, and will grace her sponge cakes and muffins.
As the first streaks of colour creep into the foliage, as the bracken turns to rust and the deergrass, Tricophorum cespitosum, the common, wiry grass of the acid upland slopes, lends a ginger wash to our hill ground, so the rowan trees are burdened with tight bunches of berries as blazing scarlet as a harlot’s lipstick. In a week or two they will be stripped bare by migrating thrushes, fieldfares and redwings from Scandinavia, undulating in chattering hordes across our hills and glens in their tens of thousands, but for now they attract an unusual marauder. Eugenia will collect baskets of the berries to boil down and render into rowan jelly, a mildly tart accompaniment for venison, other game such as grouse, woodcock and duck and, best of all, with good old-fashioned mutton. She will produce dozens of jars of the bright orange-pink jelly, a supply to keep us going all year. But it is not Eugenia’s depredations on the brightly adorned trees that I am referring to.
No one expects a carnivore to have a passion for fruit, especially not a fruit that appears to be so unpalatable. To the human tongue rowan berries are almost impossible to eat raw. The soft red flesh produces a bitterness as sharp and dry as a crab apple, so sour and with a grimacing after-taste that even when you have quickly spat them out, your soft palate is left cringing. No one in their right minds would eat rowan berries off the tree. For Eugenia’s jelly they need to be rendered down, the seeds strained out, then boiled again with oodles of sugar and the same quantity of cooking apples before the bittersweet juices coagulate into a surprisingly delicate and piquant flavour.
No such delectation for the pine marten. He takes his berries raw off the tree – and he gorges on them every September. We don’t really know why this is, but it seems likely that they are a very rich source of vitamin C, which may be lacking in their diet if other mammal prey, such as field voles, are in short supply. Pine martens are omnivores despite their pointedly carnivorous dentition. It is well known that peanuts and strawberry jam will attract them to bird tables and they are known to consume large quantities of bilberries as well as other fruits.
On our bird tables I have tried them on many different foods: rhubarb crumble, apple pie, fruit cake, roast potatoes, baked beans and much more. They take the lot. Once in a week of vicious winter frost I took a hunk of stale fruit cake out for the starving blackbirds to pick at. No sooner had I placed it on the table than a marten popped out from under a bush, leaped onto the table, grabbed the entire hunk and made off with it back into the undergrowth, all while I was still standing there.
I recently took off with Alicia, our staff naturalist, to explore some rowan trees up in the woods to see to what extent they had been raided by martens. We examined about twenty trees, all laden with dense clusters of fruit. Seventeen of them had been raided. The problem for the martens is that, although they are excellent climbers, the fruit grows on the extremities of the slender branches, too far out and too slender to carry the weight of the marten. So it has to climb up, get as close as it can, bite the twig off so that it falls to the ground, then nip down and feast on the spoils. Most of the trees we examined had a ring of scattered berries and stripped clusters around them. I had never witnessed this happening, but I have seen the consequences virtually every year, immediately followed by little piles of marten faeces deposited in prominent places on paths, on gateposts, on boulders. They are unmistakable: the rowan berries are only partially digested and clearly pass through the martens at high speed, looking more like a vomited bolus than faeces – a rowan purge. This intriguing behaviour will continue for as long as the berries are available on the trees.
What it suggests to me is that the martens may have difficulty in obtaining as much live mammal prey as they would like. Certainly, having witnessed them chasing red squirrels through the trees, and seeing the squirrels outwit and out-climb them on many occasions, I can well imagine that it is inefficient to expend so much energy on the chase. Field vole populations famously soar and then crash. In lean years, the martens may not be able to get as many as they need to supply them with the essential vitamins taken in by the voles in their catholic and seasonally variable diet. Also, of course, the hand of man is in this. Farm fields and dark commercial forests are famously devoid of small mammal prey driven out by monoculture and the application of fertilisers and pesticides. It is just possible that because we have so manipulated the natural habitat of pine martens, their feeding habits have been forced to change towards a more omnivorous diet. If so, that constitutes an intelligent survival shift for the species. When the autumn bonanza comes along perhaps some arcane metabolic alchemy is telling them to gorge on the vitamin-rich berries while the going is good.
* * *
When I came to live in the Highlands in 1968 the pine marten was a very rare mammal, largely restricted to the remote north-west Highlands. I so well remember the excitement of seeing one for the first time. Traditional persecution was falling away. There were fewer gamekeepers on the land and,
most significantly of all, in the late 1970s the Forestry Commission took the controversial decision to cease ‘vermin’ control on its land – no more employing trappers, no more fox snares, no more men with guns patrolling their woods; this at the same time as an annual planting-target driven expansion in commercial woods right across the uplands.
The resulting dramatic increase in commercial forestry during the 1970s, 1980s and 1990s undoubtedly helped pine martens by providing relatively undisturbed sanctuary and an accidental ready food supply. In those days new plantation forests were established by deep ploughing, the young trees elevated above surrounding weed competition by being planted on top of the turned furrow at the same time as draining the ground. It also laid the substrate bare, broke through cloying, water-retaining peat and revealed minerals. As always, nature motored in and exploited this new opportunity. Grasses, weeds and other nutritious plants sprang up on the naked sides of the furrows. Field voles followed the surge of new growth.
During the establishment stage of new plantations, before the canopy closed off the sun, the voles thrived on the turnover of nutrients, the fresh grasses and other plant food. In some plantations there were vole plagues immediately following planting and for the first few years afterwards. Predatory birds, such as hen harriers, short-eared owls, barn owls, buzzards and kestrels, all benefited from the vole glut and pine martens were likely beneficiaries too, especially where new plantations were created beside more mature ones, providing both sanctuary and an increased food supply. As is so often the case when several ecological factors merge simultaneously, dramatic results occurred. Here, the convenient combination of a sudden marked reduction in persecution, the presence of a vole glut and the dark sanctuary of new forests greatly advantaged the pine marten. Their numbers rapidly increased.
Gods of the Morning Page 21