The foresight of the animal is so much the greater the more remote the future for which he prepares. The Carnivora live from day to day and lay up no stores; it is the Rodents, certain frugivorous birds, and insects who exhibit the most complicated acts of economy.
Provisions laid up for a short period. — As a rudimentary example of the art of preserving food in view of possible famine, I may mention the case of the Lanius collurio. I have already spoken of this bird and of his custom in days of abundance of spitting on thorns all the captures he has made. One may see side by side Coleoptera, crickets, grasshoppers, frogs, and small birds. It is evident that these reserves cannot be preserved for more than a day, or at most two days. The bird amasses just enough to show us his apprehensions of the possible future lack of success in hunting, and his thought of preserving the surplus of the present in view of privations to come.[47]
The Fox, a very skilful hunter, has no trouble in finding game; of all the Carnivora he is, however, the only one who is truly foreseeing. The others in presence of abundant food gorge themselves, and abandon the rest at the risk of suffering to-morrow. The fox is not so careless. If he has had the good fortune to discover a poultry yard, well supplied but ill watched, he carries away as many fowls as he can before dawn and hides them in the neighbourhood of his burrow. He places each by itself, one at the foot of a hedge, another beneath a bush, a third in a hole rapidly hollowed out and closed up again. It is said that he thus scatters his treasures to avoid the risk of losing all at one stroke, although this prudence complicates his task when he needs to utilise his provisions. The fox, however, loses nothing, and knows very well where to find his stores. The very nature of the game prevents him from keeping it more than a few days.
Provisions laid up for a long period. — The Rodents, who live on dry fruits or grains, can on the other hand preserve them for a long time in their barns. The Squirrel, who may be seen all the summer leaping like a little madman from branch to branch, and who seems to have no cares except to exhibit his red fleece and show off his tail, is, contrary to appearance, a most sensible and methodical animal. He knows that winter is a hard time for poor beasts, and that fruits are then rare or hidden beneath the snow; in the autumn, therefore, when all the riches of the earth are abundant, and beech-nuts, acorns, and chestnuts have ripened, he harvests quantities of them and hides them wherever he can. Making use of the cavities he is acquainted with around his domain, hollow trees, holes that he makes in the earth beneath bushes, etc., he fills them with fruits, and when winter has come he extracts them to munch.
Animals who construct barns. — The Field Rat of Hungary and Asia (Psammomys) gathers wheat during the summer. He cuts the blades and transports them to his home, where he stores them up in very considerable quantities; and during rigorous winters when famine appears also among men, gleaners of another species appear on the scene and seek for corn under the earth in the nests of the Psammomys. A single rat can store up more than a bushel. Those who are skilful in finding their holes can thus in a day glean a good harvest, to the detriment of the rats who are thus in their turn reduced to beggary.
The Hamster also makes provision of grain, but he introduces two improvements: the first at the harvest by only taking the edible part of the ear, and the second by constructing barns distinct from his home. Each possesses a burrow composed of a sleeping chamber, around which he has hollowed one or two others communicating with the first by passages, and intended to serve as barns. The old and more experienced animals prepare even four or five of these storehouses. The end of summer is their season for work. They scatter themselves in the fields of barley or wheat, pull down the stalks of the cereals with their anterior paws, and then cut off the ear with their teeth. This done, they set about thrashing their wheat — that is to say, they separate the grain from the straw by turning the ear round and round between their paws. When the grains come out they pile them up in their cheeks, and thus transport them to one of the chambers already mentioned; they then return to exploit the field and continue these labours until they have completed the stores for winter.
A certain Vole (Arvicola economus) acts in much the same way as the Hamster, though he harvests a different class of objects. It is not wheat which he collects but roots. He has to find these roots, to dig them up, to cut them into fragments of suitable dimensions for transport, and finally to pile them up in rooms disposed to receive them. This species, which inhabits Siberia, measures about twelve centimetres in length, but during summer and autumn Voles accomplish an amount of work which is surprising having regard to their size. The moment having arrived to think about winter, the Voles spread themselves about the steppe. Each hollows little pits around the roots he wishes to extract. After having bared them he cleans them while still in position, so as not to encumber his storehouses with useless earth. This preparatory labour having been completed, he divides the root into slices of a weight proportioned to his strength, and carries away the fragments one by one. Seizing each with his teeth, he walks backwards drawing it after him, and thus traverses a long road, crossing paths, going round tufts of grass or other obstacles, not letting himself be rebuffed by the difficulty and length of the task. Arrived at his hole, he enters this also backwards, drawing his burden through all his galleries. His dwelling, though the entrance is rather more complicated, resembles that of the Hamster. Like the latter, it is composed of a central room placed in communication with the outside by a maze of passages, which cross one another. That is the sleeping-room, the walls of which are well formed, and which is carpeted with hay. From this various underground passages start which lead to the storerooms, which are three or four in number. It is to these that the Vole bears his harvest. Each compartment is large enough to contain four or five kilogrammes of roots, so that the little rodent finds himself at the end of the season the proprietor of about fifteen kilogrammes of food in reserve. He would have enough to enable him to revel in abundance if he were able to reckon without his neighbours. This diligent animal has in fact one terrible parasite. This is Man, who will not allow him to enjoy in peace the fruits of his long labour and economy. In Siberia, a long and severe winter follows a very hot summer; in this season the inhabitants often lack provisions. A moment comes when they are glad to make up for want of bread by edible roots; but the search for these is long and troublesome, and should indeed have been thought of during summer. Man, during the fine weather less foreseeing than the rodent, does not hesitate when famine has come to turn to him for help. As he is the weaker, the Vole is obliged to submit to this vexatious tax. According to Pallas,[48] the inhabitants seek these nests full of provisions and dig them up. The conqueror takes all he pleases, and abandons the rest to the unfortunate little beast, who, whether he likes it or not, has to be content. In this region the burrows of the Vole abound; therefore this singular tithe ensures a considerable revenue to those who levy it, as may be understood when we remember the extent of the stores amassed by the animal.
A Vole resembling the Arvicola arvalis, but larger, paler, and more rat-like, with large shining eyes and very short tail, overran in 1892-93 the classic land of Thessaly, the land of Olympus, and the Vale of Tempe. It has always inhabited this region, and the old Greeks had an Apollo Smintheus, or Myoktonos, the Mouse-destroying God. “At the beginning of March,” according to Prof. Loeffler, who has given an account of this invasion,[49] “the Voles were only beginning to troop from the slopes of the hills and the fallow-lands to the cultivated fields. It was frequently observed that they followed regular paths during their inroads. Thus they advanced along the railway embankment. Their progress seemed to be rather slow. Perhaps they do not advance further till the inhabitants of one of their strongholds or so-called castles have become too numerous. The runs which they excavate are at a depth of about twenty to thirty centimetres below the surface of the ground. The extent of their runs varies, and we found them extending in length from thirty to forty metres and more. These runs are connected with the surface by vertical holes of about five centimetres in diameter. In many places four, five, and more holes have led to the same run. In such cases there is generally, not far off, an enlargement for the nest, lined with finely-ground vegetable material, where the young are produced and reared. In front of newly-opened holes the earth, which has been thrown far out, forms smooth hillocks. There were many well-defined and well-trodden paths on the ground, by which the Voles pass from one hole to another. They are never seen out of their holes by day, not even in places where the entire ground is riddled with holes like a sieve. They do not come out in search of food till the evening; even then not many are to be seen, but the peculiar squeaking noise they make is to be heard everywhere. Next day all sorts of freshly-severed plants are to be found in the holes. Stalks of corn they manipulate by standing on their hind legs and gnawing through the stalk; when this is bitten off they drag it into their holes to devour it there, sometimes making it smaller. They do their work with amazing rapidity. One evening a field was visited which was to be mowed next day, but when the labourers came in the morning they found nothing to cut. The Voles had destroyed the entire crop in a single night. A miller in the neighbourhood of Velestino reported that he went to his field early one morning, cut a measure of corn, loaded it on his ass, and brought it to his mill. When he returned to his mill with a second load he found scarcely a vestige of the first remaining. Thinking it had been stolen he kept watch for the thief; but suddenly, to his great astonishment, hosts of Voles appeared and set to work to carry off the second load.” Such facts as these recorded by Loeffler are by no means a merely recent phenomenon; Aristotle was familiar with the devastations of the Voles, and wrote that “some small farmers, having one day observed that their corn was ready for harvest, when they went the following day to cut their corn, found it all eaten.” Other ancient writers record similar facts.[50]
Two birds of North America, belonging to the Woodpecker family, prepare their provisions for the bad season with consummate art; not only do they harvest them and place them in shelter, but they arrange them in such a manner that at the right moment they can utilise them in the most convenient manner.
One of them which is common in California, the Melanerpes formicivorus, nourishes himself, as his name indicates, by insects, and especially ants. All the summer he gives himself up to this hunt, but at the same time he collects acorns, which he does not touch, however, so long as he can find other food. He amasses them in the following ingenious manner: he chooses a tree and hollows out in its trunk a cavity just capable of receiving one acorn. He then carries a fruit and introduces it forcibly into the hole he has just made. Thus buried, the acorn can neither fall nor become the prey of another animal. In the domain of these birds trees may be found which are riddled like a sieve with holes stopped up by an acorn as by a plug. When the hunting of insects ceases to be fruitful, the Melanerpes visits his barns. If an ordinary bird wished to eat one of these fruits, at each stroke of his beak, on account of the polish and convexity of the acorn’s surface, it would escape him, and only by a series of reiterated efforts would the interior be exposed; but for the American woodpecker the task is simplified; each acorn being maintained firmly in the bark, it is sufficient to break the envelope and the pulp is easily seized.[51]