You don’t care about history? Well, perhaps but history cares about you. Or rather, it affects you and the world you live in, explains how you got to where you are, your successes and failures – and where you might yet go.
Of course, what I said earlier was kind of a slick answer; history doesn’t really care about you …. or about me …. or anyone else. The wind moves the trees, fills the sails, cools us or brings rain or snow – it affects us, moves us and things around us …. but is not moved by us. That is a useful metaphor because often people think they can stop some things happening by wishing strongly that they would not. Liberals and social democrats, for example …. But the metaphor breaks down – unlike our relationship with the wind, we can move things.
The shape of a tree testifies to the forces that have come to bear upon it as it was growing and its bark rings tell us of years of plenty or scarcity. To say that you don’t care about history is like, in a way, saying you don’t care about your childhood. That period of your past life and the influences that came to bear upon it and how you reacted to them have made you, to an extent, who you are today. Certainly they have hugely affected you, as any psychologist will tell.
If you really don’t care about history, you should not care whether you experience pain or pleasure. Typically, humans like to repeat pleasure and to avoid pain. But how do we know in advance what will give us pleasure or instead cause us pain? Experience. And that too is a kind of history. Which may also teach us what pleasure may be reached through pain, as for example in certain kinds of exercise – or what pleasures may end in pain, as with addictions. And we don’t only have our own experience to go on but that of many others, in their stories and in the accounts of those who have studied them. Another kind of history.
To say that you don’t care about history is to say that you don’t care about cause and effect. You don’t care about science, in other words. Science, in the sense of observation of processes and in the sense of experiment, is a kind of history. If you do this to that, in this atmosphere at that temperature, this will be the result. How do we know? It has been observed or tested, time and time again and recorded. Very like history.
Perhaps history was not taught to you in the way most suited to you at the time. Or rather, perhaps it was not introduced to you as it would best have been. A required subject to study, to gain marks and to ignore forever afterwards is hardly likely to inspire. A list of dates, of kings and queens, of prime ministers, along with their desires, though they figure in it, is not really history. “Facts” without encouragement to challenge, to interpret, to ask and to search for why and how – these drive some minds away while others learn them – but only as dogma.
Kings, Queens, Generals and Leaders of insurgents helped make history – but they didn’t really make history, though we are told they did and often say it ourselves. No king built a castle or a city though we are often told that is what happened. People build castles and cities: they dig foundations and sewers or latrines, dig wells or canals, cut timber and stone, mine and forge metal, construct buildings, grow food, settle, take up livelihoods, raise children, study nature, perform arts, record in print or orally …. History was made by people, ordinary people mostly with a few extraordinary individuals; history was made by people like you and I.
Or perhaps you acknowledge all that but think ok, as an ordinary person, there is nothing you can consciously do to alter the course of things now? Yes, our masters would like you to think that. The reality is that you can make choices: to join that organisation or movement, participate in that action or demonstration …. or not. To vote for one person or party or another – or to abstain. To treat people in this or that way.
What will help you make those choices? Well, for a start, your experience. And experience is a personal history. I did that and this happened; I didn’t agree with that outcome so now I will do something else. But we also have the experiences of millions of others upon which to draw, across thousands of years. History.
You are not an isolated individual and your people, your nation or state, is not an isolated mass. The productive forces of emerging capitalism struggled with monarchy and feudalist systems and elites and produced republicanism. Republican ideas were promoted by English and French intellectuals, for example and found receptive minds among the capitalist sons and daughters of English colonists in Ireland, bringing about the bid for a democratic parliament of all the people in Ireland. When that attempt failed, the ideas impelled some to found the United Irishmen, which hundreds of thousands of others supported because they wished for freedom from the colonial power. Less than a decade after the failure of Grattan’s Parliament to admit representation by Catholic and Dissenter, the United Irish rose in revolutionary upsurge. That was in 1798 and they looked for support from republican France, which had its revolution less than a decade earlier, in 1789. The Irish and the French republicans were encouraged by the American Revolution, which had begun in 1765 and emerged victorious in 1783.
The republican revolutions were carried out by the ordinary mass of people but it was the capitalist class that they brought to power; today the working class struggle to overcome them and come into power themselves, for the first time a majority class taking power and holding up the possibility of the end of classes and therefore of class exploitation. “The history of all hitherto existing society is the history of class struggles”, wrote Karly Marx and Frederick Engels in the Communist Manifesto, published in 1848.
You are in history. You are a product of history. What you do now affects the historical outcome to some degree at least – to one degree or another you are making history. You might as well study its process and use its lessons to illuminate your way: the distilled and concentrated experiences of millions of human beings like you.
This month the shamrock is blooming all around. The cluster flower is not very prominent individually but together can produce a yellow-green carpet effect, yellow for the flowers and green for the leaves.
Who is to say that the shamrock has a yellow flower? Why not the white clover? Well, amateur botanist and zoologist Nathaniel Colgan (1851-1919) once asked people from around Ireland to send him specimens of what they believed to be an Irish shamrock and identified the five most common plant species, of which the two most common were the yellow (flowering) clover followed by the white.A hundred years later, Dr Charles Nelson repeated the experiment in 1988 and found that yellow clover was still the most commonly chosen. According to Wikipedia, yellow clover is also the species cultivated for sale in Ireland on Saint Patrick’s Day and is the one nominated by the Department of Agriculture as the “official” shamrock of Ireland.
But sometimes, the yellow-flowered speciesTrifolium dubium (Irish: Seamair bhuí) can be found growing next to the white-flowered Trifolium repens (White Clover; Irish: Seamair bhán), although they never really intermingle.
The clover family belong to a group of plants that have the ability to fix nitrogen in nodes around their roots and, as a result, provide nutrition for plants that need nitrogen.The plant, like the rest of its family, produces pods but in the shamrock’s case, the pods are tiny and contain only a single seed. Pods protect the development of seeds until they are ready to shed (or in some cases, like the gorse or furze, to explode!).
In cropped or mown lawns, or in poor soil, the shamrock hugs the ground. However, given conditions for growth but having to compete with other plants for sunlight, it will grow long stems reaching upwards.
Once flowering is over, probably in August, one can dig up a small section and transplant to flower box or pot in order to harvest sprigs of it for St. Patrick’s day on March 17th (a tradition that is nothing as old as people might think).
But nobody planted the shamrock in the lawn – it got there by its own natural methods, possibly by wind or in animal excreta. Unlike the lawn on which it has set up its colonies, which was seeded on raked earth or, more likely, laid in grass turf rolls, it is in fact a part of wildlife in the city.
Deire-Fómhair (‘October’, also “End of Autumn’), an exhibition of art by Eoin Mac Lochlainn, was on show this afternoon in the Olivier Cornet Gallery in Great Denmark Street , Dublin and I went along to view it. An installation and 24 paintings are listed.
It is of course the installation that first catches the eye, mainly due to its size, secondarily its colours and viewing it one must, I think, come to the conclusion that the space is too small for it. Artists I suppose must use whatever exhibition spaces are available to them. Standing back as far as one can, the installation still does not reveal its full potential. But photographing in the gaps between the hanging pieces in the first row, one sees tree-trunks, dappled with slanting autumnal light through dying leaves, moss and lichen pattern on trunks and the autumn leaves themselves.
The installation is composed of 64 painted lengths of rice paper and is lit from behind with accompanying recorded bird song which adds to the ambience. In the leaflet accompanying the exhibition, the artist wrote:
This is a traditional paper which originated in ancient China and has been used for centuries for calligraphy, artwork and architecture. It is as white as alabaster, known for its strength and smooth surface, very delicate when wet but said to last for a thousand years – an enchanting medium with which to work.
Around the wall are a number of watercolour paintings, mostly 15×19, some 12×12 and a few 20×20 and one, very different in style and composition, of 45×33. The latter looks older and by another painter and appropriately so, perhaps, since it is an interpretation of a painting by the German Romantic landscape painter Friedrich (1774-1840), “Solitary Tree”, painted probably (according to Google) in 1822, nearly two centuries ago.
The subject seems to be an oak, its upper trunk dead but with leaves on branches spreading further down. It seems to have weathered many storms and perhaps a lightning strike years ago …. but it yet remains, stubbornly alive.
I do not know what motivated either Friedrich or Mac Lochlainn to take this image as their subject but in the leaflet, the latter has written:
Trees are a link between the past, the present and the future. The majestic stature, the long lifespan and the familiarity give them a monument-like quality but they also have a special aura that is difficult to define. Research has shown that within minutes of being surrounded by trees, our blood pressure drops, our heart rate slows and stress levels begin to reduce.
Less calming no doubt are the images of the watercolours which he titles Dóite (‘burned’ but also: ‘wasted, laid bare, destroyed’). The images are bleak, disturbing, of dead tree-trunks in a wasteland. In the accompanying leaflet, the artist notes:
I have been developing a body of work which explores the effects of climate change and in particular, reflects on the significance of trees.
These images could also reflect the negative effects of acid rain, nuclear or chemical contamination or timber monoculture and the exposure of trees thereby to increased likelihood and intensity of infestation by invertebrates and fungi (as for example the latter is attacking pine plantations in the Basque Country).
The watercolour series titled Cosán Coille and Siúlóid Sléibhe are exquisite colour and tone in a way of which I think only watercolours can be. It is surprising then to learn that Mac Lochlainn’s previous work has been in oils and that he found the change exacting:
In recent years, I switched from oils to watercolours in order to have less of an impact on the environment.
The switch has been both challenging and rewarding – challenging to master the idiosyncrasies of the medium but very rewarding in discovering new possibilities and avenues of enquiry for my practice.
The smaller size of the paintings restrains one from being pulled into them, the way a larger painting might do but that does not prevent them from being beautiful, sometimes in an almost painful way.
Trees have been called “the lungs of the world” and were considered of great importance to the Celts; the Gaels peppered our place-names with references to them: abhall (apple), áirn (sloe, fruit of the blackthorn), beith (birch), caorthainn (rowan), coll (hazel), cuileann(holly), dair (oak), draighneán (blackthorn), fearnóg (alder), fuinnseog (ash), giúis(fir, pine, deal), iúr (yew), sail or saileach (willow),sceach (whitethorn, normally).1 They appear also in many of our folk-songs.
Prices of paintings range from 380 Euro to 1,200 and the gallery offers a service of payment by installment. The artist, Eoin Ó Lochlainn, who happens to be closely related to Patrick Pearse, has had numerous exhibitions in each year going back to 2013 and has won a number of awards. Collections of his artwork are held inAIB, Bank of Ireland, OPW, Revenue Commissioners, AXA Insurance, Foras na Gaeilge, Gael Linn, the Boyle Civic Collection, Wesley College, University of Limerick, Donegal County, Cló Ceardlann na gCnoc.
You sniff the scent of blooms in the air and it pleases you. But that’snot what it’s for – the scent was not manufactured to please you. Scents derived from plants are used by humans to add to their sexual allure and plants also have a sexual function in producing them — but it is not humans the plants are trying to attract.
The scents are there to attract pollinators, insects, mammals or birds that will go to them to collect pollen and/ or nectar, in the course of which they will spread pollen from plant to plant and bring about fertilisation.
There are huge numbers of different chemicals producing scents and combinations of scents and, as the plants have developed them, their pollinators have also developed the ability to distinguish between them and to home in on the appropriate ones. It is likely that inside the pollinators some kind of receptor is created which is keyed into the specific scent, in much the same way as sexual pheromones are keyed into receptors inside so many species, including humans.
These pollinators then, quite unintentionally, dive into another bloom somewhere and like some kind of romantic couriers, deliver the pollen to the eager recipient. But unromantic really, to receive fertilisation from an unknown lover, unseen and barely felt. Yet it works, as around 400,000 flowering plants testify (though not all flowers use scent — colour and form suffice for some). And it will continue to work, as long as there are pollinators around (which is turning out to be a problem with large-scale deaths of bees, by far the most active of pollinators). But the animal kingdom? With some exceptions, its members need the presence of both sexual actors or more and stimuli to engage in sexual activity that will lead to procreation: temperature, light, foods, natural odours, shape, touch, erotic imagining, poetry, music, clothing, colour …. and yes, applied plant and artificial fragrances.
The scent of flowers is composed of a variety of VOCs (volatile organic compounds), most plant scents being composed of many compounds and some of up to several hundred. Collecting, isolating and analysing these compounds present great challenges to scientists but even small insects know what they mean, like an olfactory equivalent of a neon sign: NECTAR AND POLLEN HERE!.
Some plants emit scent throughout daylight and some at specific times of day only. And some not until after the sun has set. At night of course the plants do not have much competition but which pollinators will be active at night? Moths are the big group here but there are others, such as some bats.
There’s a night-scented shrub near my home that made me want to look into this subject and write about it a little. This time of year at night it is producing a strong sweet scent (with, to my nose, just a touch of urine smell in there too). You won’t find moths flying around at this time of year in Ireland and it’s not attracting bats so I guessed that it’s a foreigner and, where it comes from, that this time of year would be perfect. The shrub in question is the “Sweet Box” (Sarcoccoca confusa) and I was not surprised to find that its “native heath” is in eastern and southeastern Asia and the Himalayas.
People like the scent but it’s kind of sad when one thinks more about it, what it’s trying to do, like posting a message of sexual availability and procreation-wish on to a dating page and …. no-one replies.
Blooms and other parts of plants also produce scents which do not appear to have any role in attracting pollinators and scientists believe that these are defensive scents to ward off herbivores. In this case the olfactory sign is saying: “HORRIBLE TASTE! REMEMBER?” Not only that but plants can increase the production of such scents as parts of them are being eaten, to the extent that their attacker feels obliged to desist1. And some scientists also speculate that scents for pollinators developed first as scents to discourage herbivores.
Given that some animal appropriators of plant products have learned to home in on the repellent scents of some plants this seems quite likely. Imagine a plant exuding a smell to ward off a herbivore and imagine an insect learning that where that particular smell is to be found, so is food such as nectar or pollen. The sign now says: HORRIBLE-TASTING TO HERBIVORES AND PARASITES but is accompanied by another sign that declares: FREE DELICIOUS FOOD FOR OTHERS! And the plants that most reach and “please” the accidental pollinators will naturally be more successful, be visited more often and spread their genes wider. Unless yet other animals learn to follow that scent in order to consume the plant, or lay their eggs on it for the larvae to feed on the plant. Cabbages and carrots for example, both of which have an odour we can identify, have eggs laid on them respectively by the cabbage butterfly and the carrot fly, which are then fed upon by the larvae as they hatch. And the butterfly and carrot fly find the plants by smell.
It is a difficult balance, to attract pollinators and yet repel herbivores and parasites and no doubt the balance is constantly being adjusted through the evolutionary processes of plants, herbivores, pollinators and parasites, in a kind of dance of love and death.
Those volatile compounds to be found in the scents of flowers almost certainly also make them difficult to keep fresh. The cut flowers business is a billion-euro one and growers have now produced blooms that last longer after cutting than they used to – sometimes for weeks. But scent?One of the most delightful scents to the human nose is that of the rose, about which songs have been sung and poems composed. Go into a florist, go to a bunch of roses and try and smell them — the chances are you won’t be able to.
Shakespeare’s Juliet, who said that “a rose by any other name would smell as sweet”2 might say today that “A rose without a scent is but half a rose”. When you do find a rose or another flower that is sweetly scented, breathe deep and enjoy the scent … but remember it’s not made for you. It’s for another flower, through the agency of a courier, a messenger.
They are all around us; they live but they are not animals. Nor are they micro-organisms – we see them clearly all in many places. They can grow on organic and none-organic surfaces. We might think they are plants – algae, moss or fungus but they are none of those — they are lichens. There are about 20,000 known species1 and they cover an estimated 6% of the Earth’s surface, able to exist in environments as different as beneath Artic snow, on salt spray-showered seashores and windswept mountain rocks and in tropical rainforest. An estimated 6% of the Earth’s land surface is covered by lichen species.2 Some are long-lived and include the longest-living things on Earth. There are species that require nothing to cling to while others can live inside rock, in the spaces between grains.3In Ireland, 1,134 separate species of lichen have been recognised, according to the National Biodiversity Data Centre – i.e over 5% of Earth’s estimated total species right here on this little island.4
When we look at some growing on tree bark or rock, we are tempted to think of them as fungus, algae or even moss. Mosses are ancient enough life-forms and are plants, which algae are too and almost certainly much older. Fungi used to be considered plants but are so no longer and in their structure and digestion and also genes, are more akin and more closely related to animals. This will not be good news to vegetarians or vegans but the evidence is difficult to deny.5 Indeed there are some feoilséantóirí (word in Irish for a vegetarian and more apt in the context of this sentence) who already dislike eating many fungi because the texture reminds them of meat.
But lichens are neitherfungi nor plants.
So if lichens are not plant or fungus, what are they? Another kind of life-form? Well yes … and no. They are a combination of both, fungus and plant. At some point in the evolution of life on earth, logically after plants and after fungi had evolved, somehow some species of fungi combined with some species of alga and/or cyanobacteria6 and produced a symbiont or biont: lichen. Scientists maintain that the 20,000 estimated species did not evolve from one common ancestor but that different species appeared separately at different times during the history of the Earth.
Plants draw their nutrients from sun and elements in the soil (or in some cases, in the water). Fungi, like animals, cannot get their nutrients straight from sun or soil and need to break down their alimentation materials, whether flesh or plant, in order to feed on them. In doing so, fungi are important decomposing agents – in fact, the principal ones.
Vascular plants need roots not just to cling to soil but even more importantly, to draw up water and nutrients but algae don’t; when they have any kind of roots, it is to cling to a surface and that is exactly what the lichen needs too. Fungi extend and feed through root-like growths usually under the surface of what they are feeding upon, extending from the tips; they are not roots, however and break off easily.What we see of fungi is usually the spore-bearing parts above the surface, often much the smaller part of the organism.
Plants seem to grow above ground also by elongating their tips but in fact are extending from further back, adding cells to cells to lengthen the body. All plants need a constant supply of water (cacti and succulents store water but still need to draw on the supply to live). Fungi need damp conditions. But when combined into lichens, the new species can live without water for a considerable time. So, a marriage, as they say, “made in Heaven” … or perhaps in a Hell, an environment of very dry and hot conditions alternating with the very wet and cold , where the newly-wedded ancient algae and fungi set out to build their homes.
Some lichens contain not only algae combined with a fungus but also a cyanobacterium; this partner is capable of fixing nitrogen extracted from the air and is a valuable addition to the menage-a-trois.
It has been remarked by some that the marriage of plant and fungus is not an equal one, is not true symbiosis, since the fungal partner or symbiote benefits more than does the algal. The algal symbiote produces sugar through photosynthesis and the fungus only chitin, or ‘hard‘ structure, it is argued. However, if both partners (or three) are content with the arrangement, is that not a happy marriage? More seriously, the fungal partner may contribute other factors to the symbiosis of which scientists are only just becoming aware – for example, chemicals to repel organisms attempting to graze on them and protection from the sun.
And scientists do not treat them equally either, since the species of lichen is always determined and named by them according to the species of fungus, not of the alga or bacterium.
COLOURS IN THE RAIN
So, if the claim is that we see them all around us, where are they? They may be seen on slate roof-tops, in patches of roughly circular white (not to be confused with pigeon or seagull excrement, which may also be in evidence). Yellow or orange patches are typically seen on stone, as is a black or dark brown one by the seaside. A bright yellow-green one may be seen on fallen twigs or on tree-bark, as may also a tufted-form green one growing on rock or tree.
The colours tend to be particularly vivid during or soon after rain when the cortex becomes translucent and, if there were no other reason to be grateful for the precipitation levels usual in Ireland, that would be reason enough, perhaps, should we take the time to admire the little things of beauty. Of course there are other reasons and as a Basque once said to me about the green of his native country and could perhaps even more accurately said about colour associated with the “Emerald Isle” — “It’s not green because we paint it.”
Some of the bright colours in lichens, produced by the fungus, are thought to be of use in protection from the rays of the sun and become more vivid after rain due to rapid absorption of water by the chlorophyl-holding part of the symbiont (or biont).
PIONEERS AND SURVIVORS
Lichens are considered “pioneer organisms” by botanists and geologists, i.e organisms that set out to colonise new territories. These maybe new territories in the sense that a geological change has exposed them to air, e.g from the seabed or from under ice, or from inside the earth by volcanic action or by tectonic plate collision.
Pioneer organisms need to be tough and adaptable and they often create footholds for other species, not quite so tough or adaptable, to follow after. However, given that logic dictates that algae and fungi existed before some of them combined to form lichens, the latter could not have been among the earliest colonisers of the Earth’s crust. On Earth then, they are later pioneers of newly-created inhospitable terrain.
May they be used to help create habitable environments elsewhere? It’s perhaps worth quoting these two paragraphs from Wikipedia in their entirety:
In tests, lichen survived and showed remarkable results on the adaptation capacity of photosynthetic activity with the simulation time of 34 days under Martian conditions in the Mars Simulation Laboratory (MSL) maintained by the German Aerospace Center (DLR).
The European Space Agency has discovered that lichens can survive unprotected in space. In an experiment led by Leopoldo Sancho from the Complutense University of Madrid, two species of lichen — Rhizocarpon geographicum7 and Xanthoria elegans — were sealed in a capsule and launched on a Russian Soyuz rocket 31 May 2005. Once in orbit, the capsules were opened and the lichens were directly exposed to the vacuum of space with its widely fluctuating temperatures and cosmic radiation. After 15 days, the lichens were brought back to earth and were found to be in full health with no discernible damage from their time in orbit.
In some areas, soil lichens help to bind the sand-crust or soil-crust together but lichens have also been shown to chemically attack stone, thereby helping to create soil. Lichens can also help create little environments where soil may be retained and seeds of plants germinate. However, like all species, lichens are out to help themselves and some produce chemicals to restrict the march of mosses (another pioneer species but more water-reliant), with which lichens would have to compete in many areas).
When growing on tree bark, lichens do not parasitise on the tree nor harm it in any way, merely using it as a secure base. Older trees are often covered with lichen and dead trees or branches more so, associating in some people’s minds the ill-health in a tree with the growth of lichen upon it. Circumstantial evidence may suggest the guilt of the lichen but it is completely a case of coincidence: lichen is slow-growing and the older the tree, the more time lichen has had to grow and extend upon it; the tree dies because it grows old.
The lichen will survive the dead tree for a period but it is not the killer. Now come decomposers: insects, snails, slugs and especially, distant relatives of the lichens: fungi. Without concern for their relatives, the fungi, along with the other decomposers, will reduce the tree to soil ingredients and thereby deprive the lichens of their base but, in time, providing more soil for more trees to grow and for new generation of lichens to attach themselves to the bark.
The fungus is not too discriminating and a particular species may combine with different algae species; the resultant lichens may appear to be different species but (since 2014) will be classified as the same lichen species, i.e containing the samespecies of fungus.8
The alga can also exist independently in nature but the fungi cannot. Two species in two genera of green algae are found in over 35% of all lichens, but can only rarely be found living on their own outside of a lichen.9
Sex and Reproduction
It is only the fungal part of the symbiote that reproduces sexually. When doing so, it produces spores (as do ferns and mosses) which must find a compatible alga in order to produce a new lichen, a symbiote of the fungus of the parent fungus and a new alga.
Some lichens reproduce or extend asexually, advancing across a surface and merging with another of the same species.
Uses of lichens:
When we discuss “the use” of some thing we generally mean its use for humans; lichens no doubt have many uses for other organisms, whether as food for reindeer during non-growing seasons or as micro-environments for tiny creatures. But for humans, the uses are mostly in the areas of
geological age indicators
Dyes and Pigments:
Dyes were made from the orange Xanthoria Parietina and the grey-green branched Parmelia Saxitillis to dye wools used in traditional tweed (Harris) weaving in the Scottish Highlands10and I myself have had the second of the two pointed out to me by an Aran Islander woman as the source for the rarely-used green wool knitted into a geansaí (pullover or jumper). Material for other natural dyes exist for example in Ireland but the issues are how easily they are obtained, how true they dye and how long they remain the desired colour and shade.
“There are reports dating almost 2000 years old of lichens being used to make purple and red dyes. Of great historical and commercial significance are lichens belonging to the family Roccellaceae, commonly called “orchella weed” or “orchil”. Orcein and other lichen dyes have largely been replaced by synthetic versions.”11
We know that red and purple dyes were much sought after and in some medieval civilisations the wearing of those colours was restricted to certain social classes and even to one individual (e.g the purple for the Emperor). Once Europeans had gained familiarity with indigenous civilisations of Central and South America, the red dye obtained from the parasitic cochineal insect Dactylopius coccusbecame an important export product to Europe until the late 19th Century, when synthetic pigments and dyes were invented. Despite this development, traditional hand-made textile producers, for example in regions of Mexico, continued to use cochineal dyeing. However, health concerns associated with some or all of those synthetic colourings in food have once again created a demand for cochineal and cultivation of the insect is once again economically viable, with Peru being currently the main exporter.12
Drugs and Medicine:
There is reason to believe that metabolites produced by lichens may have antibiotic effects and usnic acid, the most commonly-studied metabolite produced by lichens, is being investigated as a possible bactericide, in particular against Staphylococcus and E.coli.13
Lichens were also used in European traditional medicine, in particular based on the theory that plants that resembled human organs would be efficacious in treatment of illness of those organs. Some American Indigenous people also used them in traditional medicine treatment.
Lichens as Indicators of Geological Age and of Pollution Levels:
The science of lichenometry is a relatively new one in which measuring the type and size of lichen is used to indicate the age of exposed rock. It takes the known slow growth-rate of different lichens to arrive at an estimate of how long the rock in question has been exposed. This can be used on rock formations, landslides, stone buildings and statuary.
The tolerance (or lack of tolerance) of different species of lichen to certain types of air and rain pollutant can be used as bio-indicators. In general the “frond” or “bushy” types are less resistant to some air pollutants and the flat or “crusty” types more so. Lichens take their water from the surfaces to which they are attached and from the air and are therefore quickly affected by the water quality in rain and air.
Readers may find it worthwhile to take some time to examine the lichens growing around us, to think about their unusual ‘domestic arrangements’ and their pioneering habits. Or to inventory them as indicators of the level and content of pollution in a specific area.
And in particular, to put on rainproof or resistant clothing and to view lichens during rainfall or at least very soon afterwards.
They had been preparing for this for some time. The infants were selected, received special care and food and were raised carefully in the Palace chambers inside the Citadel. They were now adolescents, maturing sexually. As the time approached for their great expedition, the tunnels leading to the departure terminal were widened and cleared of all obstructions. Experts tested the weather conditions daily and, when the majority of these were in agreement, the Queen gave the order to launch.
The adolescents took off then, a great host of them, amidst great excitement. Their pheromones, male and female, filled the air around them and those who could, which was most of them, quickly found a partner and coupled. It was a maiden flight from which the adolescent females would land no longer maidens.
Those who would land, that is. For suddenly the air was filled with giant flying monsters with huge eyes and giant whirring wings. Much more accustomed to flight, these monsters flew among them, gobbling them up. Some even held rows of their hapless victims in their huge beaks as they flew off to feed them to their young. Hundreds, perhaps thousands of the little flyers perished in minutes.
Those who managed to land safely and didn’t end up drowning in a lake or a river, or snapped by denizens of the deep who sprang up at them as they passed overhead, or caught in sticky webs, or who were not stamped carelessly to death by huge walking giants or flattened by roaring, stinking monsters, still had to contend with smaller predators on the ground. The casualty rate was huge but some made it alive – some always did.
The males who made it down to ground safely would all die within a couple of days. Their wings were only intended for their nuptial flight; on the ground, they were nothing more than a nuisance, impeding their progress over and underground.
The females, sexually sated and no longer interested, had left their male partners behind. They bit off their own wings, ate them and, quickly finding some reasonably soft ground, began to dig. Each one dug down as though her life depended on it, which of course it did; and not only her own life – each one was pregnant. Then she blocked the entrance to her tunnel, went back down it, excavated a chamber and began to lay eggs. It was completely dark down there but she had been reared in darkness – she had one day of daylight only, the day she flew.
The young grubs who hatched were all females. She supplied them with some sparse nutrition from herself and cared for them as they grew, shed skin, grew … until they spun a cocoon from which they emerged as very small worker ants. They were infertile workers and tended to their large mother, their Queen; even when they were fully-grown she was still one-and-a-half times their size, although about half the size she had been when she left her old nest. Her most recent meal had been her own wings the day she had flown and mated. If she got past this crucial stage, she would recover her size and weight and lay more and more eggs.
The workers soon went up the tunnel, unblocked it and spilled out into daylight for the first time in their lives, beginning to forage for food. They found small seeds and, if they were lucky, sweet material such as soft-skinned ripe or rotting fruit. They soon had their surroundings covered with their hive-scent, carried by each and every worker. Sometimes they found insects they could kill but these had to be very small indeed – these workers had been fed on insufficient nutrition and were, compared to the majority of their kind, puny. If they found a food-source worth another visit, they left a specially-scented trail on their way back to their home, to guide theirs sisters back to the prize later. A rich source of food typically would show two streams of traffic between their nest and the food – one empty–jawed heading for the food and the other, with pieces in their jaws, heading away from it and towards the nest. The food gathered by the workers fed them and their Queen, while she continued laying eggs. As time went by, more and more workers were born, who would care for the hundreds of eggs their matriarch laid and raise more and more workers. Extensive tunnel networks were dug.
At some point the workers found aphids and began harvesting their sugary secretions; tending them on the stems of the plants the aphids infested and carrying them down to their citadel but bringing them back up later. The workers would fight to protect the aphids from those who preyed on their ‘herds’.
Successive generations of ant workers grew bigger, until they reached the optimum size of five milimetres (still four millimetres short of the Queen in her prime). A well-established citadel could in time house as many as 40,000 individuals (although between four and seven thousand would be more common) – they, and previous generations, all daughters of the same mother and the product of one mating only. Their Queen, barring unusual disasters, might live to 15 years of age.
Once the citadel is built, it is vulnerable in the ordinary course of things only to parasites, flood, fire and severe surface disturbance. In Ireland, without bears, wild boar and largely without foraging pigs, severe surface disturbance is unlikely away from human construction or ploughing and digging. Fire might not reach underground but the heat generated or the lack of oxygen might kill anyway; flood, of course, would be the biggest threat. If a citadel should be uncovered or invaded by flood waters, some workers will rush to deal with the problem while others rush to save the young, trying to carry eggs, pupae or cocoons away in their jaws to a safe place. Some others will rush to do whatever they can for their Queen. A black ant defends itself by running away if possible and if not, by biting. But intruders to the citadel are swarmed by biting ants. However most human skin is impervious to the bite and this species does not sting.
One day, perhaps three years from the Queen’s maiden flight, she will decide it is time to send her own children into the wider world. She will lay eggs and have these emerging grubs fed special food, which will produce males for the first time in her citadel, as well as other fertile females besides herself. Then, one day in July or in August, she will send them out too, to start new colonies.
Lasius niger, the Black or Garden Ant, is the most common of the 21 species of ant in Ireland. It is the most common also across Europe and a sub-species, L. neoniger, is known in the USA where however, it is not one of the most numerous ant species. Lasius niger is a very active, hardy and adaptable species, living mostly outdoors under rocks and but rarely inside houses (although it may well enter houses repeatedly if it learns of food within, especially sweet food). In cities, its nests are to be found in parks and gardens but also under street paving stones, the workers emerging to forage from tunnels leading to the joints between the stone. When those joints are surrounded by thin lines or small heaps of bright sand in summer, one knows that the workers are clearing the tunnels for the adolescents’ flights. Another indication is an unusual amount of
seemingly erratic ant activity around a nest, though one would need to be aware of what normal activity looked like, for comparison. The ants may delay, awaiting what they judge to be optimum conditions but someday soon, mid to late afternoon, they will take to the air, to fly, to mate, to die or to live, to start a new population.
Cycling through Griffith Park off the Mobhi Road, after a walk in the nearby Botanic Gardens, a flurry of wings and a flash of colours attracted my attention. Three birds came down with a splash into the Tolka.
You don’t need to be any kind of expert to identify the Mandarin Duck, especially the males and that’s what two of those birds were. The dowdier third one was the female.
I have often noted two male mallard ducks peacefully accompanying one female and wondered whether they had a menage-a-trois going or what the arrangement was. But there was nothing like that going on with the Mandarins as the males made clear quite quickly. After briefly circling around one another they were quickly into fisticuffs (or beak-and-wing-cuffs), scuffle-splashing, clucking insult or challenge, until the rival to the established male would take to the wing either for a break or to get next to the female. In the latter case, the male would take to the air also, in pursuit.
The female? She swam demurely apart waiting for the victor.
There was clearly one established male who for the moment was the dominant one but the rival kept coming back while I was watching and they were still at it when I left. The established one has the psychological dominance factor on his side, which is a strong advantage but it is by no means a guarantee of success. The rival might wear him down. Or the established one might become injured. Being a male and keeping one’s bird is not easy.
According to Charles Darwin, genders of many species but many birds in particular have become colour-differentiated through part of the evolutionary process described as sexual selection (The Descent of Man and Selection in Relation to Sex, 1871). This has reached amazing and one might say even bizarre though beautiful extremes with such birds as the peacock and the bird of paradise.
Darwin’s ideas make more sense than other explanations being proposed but it is nevertheless hard to credit that a female’s appreciation of colour, shape and behaviour would so impress upon the male the need to flaunt gaudy colour and shape in direct contravention of the need to survive predators by NOT calling such attention to himself. Still, there is no other viable contender explanation around (as distinct from the Mandarin contender, who may still be biding his time or pressing his suit, which if the established male has anything to say about it, is all he is going to press).
Aix galericulata is the Latin species name and the only other species in the Aix genus is the North American Wood duck. A chromosome in the Mandarin makes hybridisation between the two impossible.
Mandarin Ducks originate in East Asia but have been kept in Europe in aviaries and in ponds and lakes. Stephens Green used to have some, along with many other kinds of wildfowl, until the OPW allowed the Herring Gulls to take over to the extent that they have. I have not seen them do it but would not be in the least surprised if the gulls ate the chicks of many of the waterfowl species until they died out or took off somewhere else.
However, there have been feral Mandarin populations in Ireland for some time, notably in Co. Down and in Wexford and pairs may be establishing themselves in other places, including in the Glasnevin/ Drumcondra area, based around the Tolka (and perhaps the Royal Canal).
The Mandarin is a perching duck and this kind have feet capable of grasping a branch. They build their nests in hollows in trees which is good for the safety of the nesting female and the eggs. But what of the chicks or ducklings? As we know, ducklings take to the water long before they can fly. So what can these ducklings in tree hollows, many feet from the ground, do? They simply jump. A veritable leap into the unknown.
When they hit the ground, which at first sight seems to ensure they have broken practically every bone in their little bodies or a least concussed themselves and messed up their insides, they bounce a little, get up and waddle to their mother. Yes, she called them out, which is why they came.
One needs to see the process to believe and I have included some Youtube links. It would seem at first that they need soft leaf litter or water in which to land but one of the links I have posted shows Mandarin ducklings jumping from a nestbox on to bare stone — and getting up, apparently unhurt. It is difficult to understand, even with accounting for the relationship of weight to surviving a fall. We probably know that we can drop lots of insect species on to the ground and they don’t get hurt but the principle goes farther — apparently a mouse can survive a fall from a great height (unless a hawk gets it on the way down, or a cat is waiting below); conversely a fall of four foot on to its feet can kill an elephant (so it is said — I have not actually tried this with elephants but I have inadvertently confirmed the mouse theory).
Often invasive species should not be welcomed as they upset the natural ecological balance. The grey squirrel in the nearby Botanic Gardens, originally from the USA, may be cute but it is helping to wipe out the native red species. And that’s just one of the invasive species of animal and plant that are causing problems in Ireland (see https://rebelbreeze.wordpress.com/2014/07/01/the-scent-of-intruders/). On the other hand, the widely-distributed Red Valerian (also with white and pink varieties) does not seem to be causing any problems and it is difficult to see how the Mandarin can become a serious problem either. But of course, one does not know for sure. It can be stated that the populations so far established in Britain and in Ireland do not seem to have caused any ecological problems. And it is true that we don’t have many dense woods in Ireland anywhere (thanks to certain human invaders in our history), least of all close to slow-flowing water, although some species have shown remarkable adaptability, witness in these climes the rat, fox, pigeon, herring gull and, of course, homo sapiens.
One of the curious things about the Mandarin is the name we have for it. Apparently, it is a Portuguese word for the Chinese government bureaucrats in existence when the Portuguese first began to trade with them (before they and other Europeans decided to invade China and confiscate areas, in particular ports and islands). How they became associated with the duck was not revealed in my short internet search.
However, in China and in Korea the mandarin duck is associated with fertility, good fortune and constancy in monogamy, so that it is often presented as a wedding gift, either as living pairs or symbolically in an ornament. It is not currently considered an extermination-threatened species.
Video links (second one is of merganser ducklings and is even more impressive):