Hibernation in Hedgerow and Wood.

Evening Post, Volume LXXI, Issue 136, 9 June 1906, Page 11

Hibernation in Hedgerow and Wood.

Kind nature, apparently so careless of superabundant life, has nevertheless a gentle way of dealing with her winter unemployed — for unemployed there are in the animal us in the social kingdom. During the period of cold and want she lulls them into forgetfulness Not until now. when crocuses open to the early sunshine bnside lawns that begin to wear a fresher green, when the buds of the lilac are swelling and primroses are sprinkled along the hedgerow bank, do they one after another awaken from a lethaTgy which neither gale nor tempest could disturb. This is the history of their triumph over dearth. As tne swarms of winged creatures that fill the soft clear air of the -warmest months fulfil their destiuies, and tho numberless varieties of insect life, one after another, provide the earth with future generations and then become scarce and pass away, the summer birds wnich depend upon them for their subsistence hasten abroad to more favourable shores. Accepting the warnings of the early frosts, the last of them, knowing their occupation about to fail, migrate to warmer climes and plenty. So suddenly will they take their flight at the approach of want, that until a comparatively recent time it was solemnly contended that swallows must pass their winter undiscovered at the bottom of deep lakea and pools. But all the bits »re as de-. pendent upon the summer as the swallows themselves. Their food chiefly consists of the fluttering moths that abound in the warm dusk. When these cease the famine must commence. And the soculled wings of the bat—which, properly speaking, are not wings at all, but a leathery membrane connecting #he arms, legs, and tail to form a serviceable flying apparatus — although strong, are unfit to battle with adverse winds and the risks and dangers of a long journey. Here they must stay whether there be, food or no." Therefore, before scarcity comes*uptm them, and whilst they a'r&- still fat, • they retire to their hollow trees, their caverns, or the roofs of disused houses in which they have been used to hide by day, "end fall asleep. The cares of want are unknown to them in their prolonged

and dreamlesß lethargy. In a profound unconsciousness they jiass the dreary months of winter, whilst there is no j longer a moth to catch, until awakened ! by hunger when the warmth of spring 1 brings back their occupation and food. J.he great Nocfrulo indeed, the largest of our familiar bats, is rarely to be seen after the beginning of August until the middle of the following April. The little Pipistrelle, the commonest of them all, retires at about the same time as the swallows take their departure; and if, now and again during the last few months, a misguided individual has been seen abroad at noon upon an exceptionally mild winter day, it did but mistake a brief gleam^ of sunlight for the glance of returning spring. It may perhaps have caught a J fly or two, but very quickly it fluttered I back to creep into its dormitory and j bleep. The hedgehog also, thought he is said to enjoy a most varied bill-of-fa-re, would find himself face to face with starvation if he did not hibernate. Like the bat, he is a nocturnal feeder, chiefly upon worms, snails, slugs, and insects, but also with a taste for eggs, young birds, and even reptiles. With the cold the earth-worms bore deeper into the soil. They are not to be found amongst the winter rime as upon the dewy grass of a j summer night. Slugs also are no longer there. Snails have wept away into +he crevices of old walls, or found themselves sleeping-chambers in hollow places | behind the roots of thorn- or maple on the ! hedgerow bank. There they have filled j the openings of their shells with slime, which soom became as hard as a »vindow- 1 pane- and — unless they have left themselves within recich of the hungry beak j of the thrush — sticking to each other in j large clusters, they will pass a secure hi- j bernation of their own, to awaken only j when the tender shoots of spring provide them with an abundance of suitable food. Snakes and adders also have hidden themselves away in parties for a winter sleep, i They may strike one as an unexpected j food for the hedgehog, but it seems to be i ascertained that they provide him with j a not uncommon repast. The hedgehog tfn finding a snake is said to creep up to him, to inflict a bite, and at once to roll himself up in a ball. So slight an in- j jury incapacitates a snake that after this I preliminary attack he is rarely able to get away. Presently the hedgehog slyly opens, awaits his chance to get in another bite, and quickly rolls up again. This little game of hide-and-seek continues until the reptile ia quite helpless. Then the hedgehog systematically bites his victim, beginning at the head, and when all the vertebrae are snapped, settles down to eat him from the tail. With the adder the contest is sooner over. Aware of his Eoison-fangs, the viper strikes fiercely at is well-protected foe, and injures himself against the prickles. But the winter is nearly over now. Snakes will soon be found on the sunny bank. Hedgehogs will be moving at dusk. The little shrew-mouse, that one so often sees in autumn dead on, the path for no reason that is apparent, must have almost finished his nap by this time. [ From the snail upwards, in the 'case of each of the animals already mentioned, hibernation is profound and unbroken. But in hedgerows and woods are other cre%tures which spend much of the winter in sleep, and yet awake now and then when the weather is warm and favourable. All of these are in part nut-eaters, and lay themselves up hoards of winter provisions to which they repair in their brief intervals of wakefulness. The most sleepy of them is the charming little dormouse. Ho possesses the attractive manners of the squirrel, although his structure is more closely allied to that of the mouse. He finds his most favourable ! house in an oakwood with a coppice of | hazel-busuea, for he feeds on acorns, and nuts are Ids special delight. No sort of grain or fruit comes amiss to him, and ho varies his menu with the caterpillars that cling to the fresh leafy twigs. Low dbwn in hedge or copse he makes bis winter nest, and sleeps during half of the year. Sometimes he wakes, goes to, his hoard in some cranny under his hazelbush, and eats a nut or two. Quickly he returns to roll himself up into a ball, with his head tucked under his tail, which reaches like a fur coverlet over his back, and sleep again. But his hibernation is not so profound as that of the hedgehog. If you take- him dormant when concealed in his little ball of interwoven grass, with the warmth of the hand he soon casts off his torpor. For a while he becomes quite lively, but quickly falls asleep again when left to himself. And in his forest tree, the squirrel behaves very like his little neighbour in the copse below. But he has not the good fortune to sleep so soundly as the dormouse. At the most his slumber lasts only a few days. Then he leaves his hole, or bis drey iipon the branch of the fir or where the limbs of a beech meet, and comes down to the ground. The hoards under his home-tree are many, for he is too cunning to place all his investments in one security. The I wily little miser buries his treasure in several holes, so that if thieves should chance upon one thej r may leave him the others. Ue comforts himself with a meal I and returns for another nap. But except in heavy rain or hard frost ho is frequent- ; ly to be seen in the woods in mid-winter, I generally towards the middle of the day. j The sleep of hibernation is a very different matter from the sleep of repose. If it be complete, respiration can no longer be dcticted. A torpid bat when disturbed will heave a eigh or two ; and, being left alone, again to all Appearances ceases to breath. Submerged in water of a temperature slightly higher than his own, the hedgehog not only continues to live, but appeara to suffer neither inconvenience nor harm. Enclosed in an air- j tight receptacle, his atmosphere undergoes ' a change so slight that it cannot be iin- j puted to breathing. But circulation does not cease. As respiration diminishes, the irritability -of the muscles of the heart increases ; and thus, without the stimulus of oxygen, although much more slowly, the heart continues to beat. In the absonce of the fresh air drawn into the lungs in times of aotivity, nncleansed and unrevigoratod the venous blood passes on to fill the whole system of circulation. A profound lethargy ensues, only distinguishable from death by the slight beating of the heart. The waste is very small. The fat accumulated during the plenty of summer and autumn supplies all expenditure until the coming of spring, when earlier or later the hibernating animal, having no capital in reserve, begins to suffer the pangs of hunger. In responso to the demand respiration very slowly increases. His oxidised blood flows more quickly and his energy returns. Then the bat flics forth onca more from the hollow treo in the wood, to find the warm dusk teeming with insect life; and the hedgehog comes, it may be from the cavity under the gnarled roots below, to find beetles, worms, and slugs once more nmongst the springing grass Hibernation has saved him from starvation ; but if his nook had not been snug and wifely chosen, it could not have preserved him from death from frost. Tho hiding-place also must bo secret and free from intrusion, for the hibernating animal cannot bear to be suddenly aroused. Even the little dormouse, wnich comes out at intervals to feed, when in deep sleep does not survive too hasty an awakening. The heat of tho hand gradually passing through the nest, or to be carried indoors to tbo warmer temperature of a room, is w<«ll enough. He awakes refreshed, full of activity, and with a disposition speedily to become tame and make friends. But if you warm him suddenly back to life before ho has gradually breathed the torpor out of his blood, and established an equilibrium between his respiration and muscular irritability, his heart will beat afc a tremendous rnto, pad, in a few minutes he is dead..— Spectator.,