Chapter 4 of 18 · 3781 words · ~19 min read

Part 4

All Bats, except a few tropical genera, feed on insects, and possess teeth like those of the preceding order of Mammals (p. 30). The leading feature is the characteristic modification of the fore limbs into a flying apparatus. The bones of the fore arm (Fig. 18, _u, r_), the metacarpels (_mc_), and the phalanges (except in the case of the thumb, which possesses a sharp claw (_p_)) are of great length; and between the long fingers, between the fore and hind limbs, and, last of all, between the two hind limbs there is an elastic membrane, serving both for flight and touch. Sight ill developed, since the bat is a nocturnal animal; a delicate sense of touch has its seat not only in the flying-membrane, but also in the skin of the ears, which are often very large, and in the membranous flaps which, in a few genera (the “leaf-nosed” bats), occur on the nose and lips. As is well known, bats sleep in the day; and they also hibernate in chimneys, hollow trees, ruins, and other similar places of concealment.

They principally devour night-flying moths, and spiders; and, since they use a great quantity of nourishment, are of great service, since the caterpillars of many of the species they destroy are very injurious to agriculture or forestry. About nine species live in Britain, but there is no use in enumerating them here.

ORDER: =Rodentia= (GNAWING MAMMALS).

[Illustration:

FIG. 19.—Skull of Squirrel. ]

Two long incisors (Fig. 19), the crowns of which are continually being worn down, while a corresponding growth takes place at the root-end. These incisors are used for gnawing, in which process the lower jaw is rapidly moved backwards and forwards. Gnawing wears down these teeth less in front than behind, owing to the presence of a thick layer of enamel in the former position. Their crowns, therefore, maintain a chisel-edge. That the incisors never stop growing is clearly seen when the usual wearing down does not take place, as, _e.g._, when the lower jaw is placed obliquely under the upper jaw, or when a tooth is absent in one jaw, under which circumstances the corresponding incisor in the other jaw is not worn down. In such a case the incisors continue to grow, ultimately curving upwards or downwards, and becoming tusk-like structures (Fig. 20). The Rodents have no canines. In those Rodents which feed both on animal and vegetable food (the “Omnivora,” _e.g._ squirrel, common mouse, brown rat, etc.), the crowns of the back teeth are completely covered with enamel; in the purely vegetable feeders (“Herbivora,” _e.g._ hare, rabbit), they are compound teeth (p. 22). In most Rodents the hind feet are longer than the fore, giving a springing gait. Eyes large. Many forms have “cheek-pouches,” in which the food they obtain can be stored up for some time. When the pouches are full, a muscle contracts by which their ends are drawn backwards; they are emptied by the animal pressing them with its fore feet. The majority of Rodents are small, they are at most of medium size (hare). The majority of the species have great powers of reproduction, by which the injurious kinds are sometimes rendered a very great pest. The British forms injurious to agriculture principally belong to the families of hares, mice, and voles. The squirrel (_Sciurus vulgaris_), and the dormice (especially _Myoxus avellanarius_) are solely of importance in forestry.

Family: =Leporidæ= (_Hares and Rabbits_).

Skull somewhat long. Two small incisors behind the two large upper ones. Ears long and spoon-shaped. Upper lip cleft. Back teeth with enamel folds. Here belong the hare (_Lepus timidus_) and rabbit (_Lepus cuniculus_).

=Hare= (_Lepus timidus_). Ears longer than the head. Eyes yellowish brown. Fur rusty yellow to grey on the upper side, white on the under side. The doe litters in an open “form;” the young are born covered with hair and with open eyes. Mature animals breed four or even five times a year, producing two to four leverets each time. The hare is injurious to agriculture, eating cabbages, rape, turnips, clover, vetches, young corn plants, carrots, and grass. It also eats many weeds. It is, however, less injurious than the rabbit, for it does not burrow. The damage done by the hare is also less evident, since this restless, fastidious animal seldom feeds continuously in the same spot.

[Illustration:

FIG. 20.—Abnormal Tooth in Hare. ]

=Rabbit= (_Lepus cuniculus_). Ears shorter than the head. Eyes dark brown. Fur yellowish brown to greyish yellow on the upper side, redder in front. Under fur bluish grey. Shape more compressed. The rabbit breeds more rapidly than the hare. Five to six times yearly the doe brings forth four to eight young, which, after six months, can again reproduce. Dwelling subterranean. Young, blind and hairless at birth. As the rabbit burrows, it is limited to certain districts, for the soil must not be too stiff and firm, nor, on the other hand, too light and incoherent. The rabbit is injurious in the same way as the hare, but the damage is more obvious (see above); and as a result of its burrowing habits it does infinitely more damage. Both in sandhills and in alluvial sandy soil rabbit burrows lead to the blowing away of material only held together by sand-plants. Kept down by shooting, netting, and ferreting (p. 27).

Family: =Muridæ= (_Mouse Family_).

The mouse-like animals (the larger species of the family are called “rats”) closely resemble the representatives of the following family, but are distinguished from these (the “voles”) by their slender body, longer legs, a more pointed head with longer always clearly visible ears, and usually, with the exception of the hamster, by a tail equal in length to the body. The hind legs are longer than the fore legs, hence the hopping mode of progression. Three back teeth on each side of each jaw, possessing a tuberculated crown completely covered with enamel.

[Illustration:

FIG. 21.—The Hamster (_Cricetus frumentarius_). ]

The =Hamster= (_Cricetus frumentarius_).—The Hamster has cheek-pouches, and a very short, thick, but short-haired tail. It attains the size of the brown rat. Bright yellowish brown; belly and legs black. The hamster is found almost exclusively on fertile soil devoted to cultivation. It appears locally, and then for several years in great abundance, so that it is often caught in tens or even hundreds of thousands. Favourite food: wheat, field beans, and peas, then rye and similar grain; and, last, roots, turnips, young corn plants. Sometimes, too, the hamster eats animal food—worms, insects, lizards, small birds, eggs, and mice. As a winter store it usually only accumulates grain, beans, and peas in its hiding-place, often to the amount of more than five gallons. A little heap of thrown-out soil marks on the surface the position of its nest. The entry to this runs vertically down into the soil. Six to twelve young, twice a year. The dwellings of the hamster, which are situated in stubble-fields, can easily be found; and by digging them up, particularly in spring and late summer, when there are young ones, the number of these destructive Rodents can be greatly reduced. May be caught in traps.

=Genus Mus= (Mice and Rats) includes Rodents without cheek-pouches, and with long, scaly, ringed tails. Two large species (“rats”) belong here, namely—

The common =Black Rat= (_M. rattus_), indigenous to Europe since pre-historic times, and the stronger, somewhat larger—

=Brown Rat= (_M. decumanus_), with greyish white belly (while the first-named species is black on the upper and only slightly brighter on the under side). The brown rat migrated during the first half of the eighteenth century from Asia into Russia, and about the same time from Further India to England by means of ships. Since then it has spread all over Europe and other parts of the world, and in many regions has quite driven out the black rat. Both kinds of rat eat almost everything, and are a pest in housekeeping, as well as in agriculture. They feed on insects, mice, eggs, and chickens, will even bite pieces from the living bodies of grown poultry and fattening swine, and also devour young geese and ducks. They eat grain, peas, beans, potatoes, carrots, turnips; bread, cheese, and similar provisions. Multiply very rapidly. Can be driven away by clacking-mills, and to a great extent by noise. Caught in traps.

Besides these, four mice belong here:—

The =Common Mouse= (_Mus musculus_). Back yellowish grey-black, gradually shading into a somewhat lighter tint on the under side.

[Illustration:

FIG. 22.—The Long-tailed Field Mouse (_Mus sylvaticus_). ]

The =Wood Mouse=, or =Long-tailed Field Mouse= (_M. sylvaticus_). Back a brown shade of yellowish grey; belly white, sharply marked off; relatively very long hind legs, hence a hopping gait. The long-tailed field mouse penetrates tolerably far into woods, but is also found in plantations and gardens, sometimes also in quite treeless regions. On arable land it may adopt the habits of the field vole (p. 42), but as it does not multiply so rapidly is not nearly so injurious. It may also live either for a short time or permanently in houses, adopting the same habits as the common mouse.

The =Harvest Mouse= (_M. minutus_). Small, pretty; back yellowish brown red, belly of a sharply marked-off white. Lives in cornfields during the summer; in harvest time by the field-paths; during winter in barns and haystacks, but also in outdoor nests in the fields. Climbs among the grass and corn-haulms, and the small stems and branches of other plants, including shrubs, holding fast, not only by the feet, but also by the tail. Builds a beautiful spherical nest with a side entrance out of the haulms and leaves of grass and corn, or out of other leaves. Devours seeds, especially grain, oats being the favourite.

The =Corn Mouse= (_M. agrarius_). Back brownish red with longitudinal black stripes. In plains east of the Rhine. Usually local, but then very abundant. Chiefly in cornfields and fruitfields; digs holes in the soil. In autumn it often occurs in the field in large colonies. Food: grain, beans, peas, potatoes, turnips, carrots. In winter in the barns and dwelling-houses of farmers.

[Illustration:

FIG. 23.—Upper Back Teeth of Brown Rat, seen from grinding surface. ]

[Illustration:

FIG. 24.—Upper Back Teeth of Water Vole, seen from grinding surface. ]

Regarding the means of destroying those mice which are sometimes damaging to agriculture (_M. sylvaticus_ and _M. minutus_), see methods mentioned under “Field-vole” (p. 43).

Family: =Arvicolidæ= (_Vole Family_).

The large voles are also popularly called “rats,” the smaller ones “mice.” They closely resemble the true mice and rats (p. 38), but are distinguished from them by their plumper, more compressed body; a thicker head with blunt snout, and ears quite hidden in the fur; and a short, tolerably hairy tail, on which no rings of scales can be distinguished. There are on each side of each jaw three back teeth, of which each appears to consist of two rows of three-sided prisms, fused together along the middle line (cp. Figs. 24 and 23). The native species all belong to the genus _Arvicola_; the Bank Vole (_Arvicola glareolus_), the Water Rat, or Water Vole (_A. amphibius_), and the Short-tailed Field Mouse, or Field Vole (_A. agrestis_).

The brownish-red =Bank Vole= (_A. glareolus_) occurs in forests.

The =Water Rat=, or =Water Vole= (_A. amphibius_). Body six inches long, tail half the length of the body. Fur of one colour, brighter on the under side, varying from brownish grey to brownish black on the back, and from whitish to greyish black on the belly. On the banks of rivers, brooks, ditches, canals, etc.; also on damp low-lying meadows and fields. Digs much-branched passages in the soil; this often takes place in embankments to such an extent that it finally leads to their complete destruction. The vole also does damage in grass-fields and cornfields in the same way as the mole (p. 33). In its case, however, there is no compensating service. It certainly eats insects and worms, but its chief food is of vegetable nature; grain, potatoes, turnips, and carrots are devoured by it in large quantity, and in particular stored up in its hiding-place. It also destroys the roots of grass and corn, and eagerly devours chickens and the eggs of ducks and geese. A variety (_A. amphibius_, var. _terrestris_) occurs in dry soils, and is distinguished by its smaller size, lighter colour, and shorter tail. Its habits are the same as those of the ordinary form, but it is more given to attacking trees.

Traps, shooting, poisoning with celery stumps hollowed out and filled with phosphorus, or else with phosphorus paste.

The =Field Vole=, or =Short-tailed Field Mouse= (_A. agrestis_). A small animal, with dark brownish grey back and greyish white belly. [Lives in pastures, especially those which are low-lying and damp. Large numbers are found together, and they make deep burrows in the soil, each pair having a special nest to themselves. Three, four, or even more litters per year; four to ten young in each litter. Its favourite food consists of roots, young shoots of grass, etc., and the tender bark of shrubs, but nothing of vegetable nature comes amiss. Specially destructive in permanent pasture.]

REMEDIES. (_a_) _Preventive measures_. Protection of its natural enemies (weasel, stoat, polecat, fox, hedgehog, owls, buzzards, kestrels, the smaller seagulls). Catching in traps, etc., in the spring, when the voles are only present in small numbers.

(_b_) _Destructive measures_, which should be as generally used as possible in infested districts. If a field has been completely devastated, or the crop is over: (1) Working the soil with a spiked roller; (2) Partial inundation of the lower-lying fields. If it is desired to kill the voles and spare the crop as well, the following means may be recommended: (1) The digging of cylindrical holes six inches across and two feet deep, especially at the margins of the fields and in the furrows, as well as—at harvest time—on any footpaths that may be found. The voles fall into these holes, cannot get out again, and are starved. (2) The employment of poisons. (Care must be taken that no children or domestic animals are poisoned.) Phosphorus paste is best.

[Illustration:

FIG. 25.—The Southern Field Vole (_Arvicola arvalis_). ]

The =Southern Field Vole= (_A. arvalis_) plays the same destructive part on the Continent that the preceding form does here (Fig. 25). _Remedies_—see above.

ORDER: =Ruminantia= (CUD-CHEWING MAMMALS).

The feet end in two hoof-covered toes, besides which two “after toes” are present. The upper incisors are absent, with few exceptions, but many deer have canines in the upper jaw. The back teeth of Ruminants are compound teeth. The lower jaw is smaller than the upper, and during chewing undergoes lateral movements, so that the plants taken in as food are ground up, as it were, into small pieces, between the projecting enamel ridges of the upper and lower back teeth. The stomach consists of four subdivisions; these are (1) the rumen, or paunch, where the greater part of the food and water taken collects; (2) the reticulum, or honey-comb stomach; (3) the psalterium, or manyplies; (4) the abomasum, reed, or rennet stomach. The last is the second largest part, and in it the same chemical changes take place as in the simple stomach of a non-ruminant. After the food has remained for some time in the paunch it passes up again through the gullet, and [as the “cud”] undergoes a second chewing. The soft mass resulting is once more swallowed, and passes into the psalterium and abomasum.

[Illustration:

FIG. 26.—Skull of a Sheep. ]

Not only the families of _Tylopoda_ (Camels, Llamas), and _Camelopardalidæ_ (Giraffes), but also the large family of _Cavicornia_, to which, amongst others, the ox, sheep, and goat belong, will be passed over in this book. I need only mention the—

Family: =Cervidæ= (_Deer Family_).

Deer have branched horns, known as antlers. With the solitary exception of the reindeer, they are only found in the males. They are bony structures borne upon projecting knobs (horn cores) of the frontal lines. After each rutting-season the antlers are cast, new ones, clothed at first with a soft skin [the “velvet”], are developed. Before the next rutting-season the dermal part of the skin unites firmly with the underlying antler, and becomes itself ossified, while the epidermis shrivels up, partly peels off in bits, and is partly rubbed off by the animal against tree trunks. If the conditions of life (food, weather) are favourable, the animal acquires a new side branch to each antler every year, at any rate, so long as he continues to get bigger and stronger. The one-year-old male (“brocket”) has therefore a simple unbranched antler, the two-year-old (“spayad”) one side branch as well, the three-year-old (“sorel”) three points in all; the four-year-old (“staggard”) has four points; the five-year-old (“stag”) five, and so on.

[Illustration:

FIG. 27.—Development of Roebuck Antlers. ]

In Britain two indigenous deer are found—the Red Deer (_Cervus elaphus_) and the Roebuck (_C. capreolus_); a third species, the Fallow Deer (_C. dama_), lives in South Europe and Asia Minor [and the exact date of its introduction into Britain is not known].

The =Red Deer= (_Cervus elaphus_). Six to seven feet long, and four feet high. Antlers rough and cylindrical for their entire length; each in its normal condition has two front branches [“brow” and “bez-tyne”], a middle branch [“tres”], and a “crown.” Tail small. Body of a brownish colour, becoming red in summer. A light yellowish brown spot on the tail. Male larger than the female, with long dark hairs on the neck during the breeding season (autumn). The young (“calves”) are spotted with white till their first change of coat in October. The hind brings forth one or rarely two calves in May or the beginning of June. The stag sheds his antlers at the end of February; the new ones are already full-grown in July. So long as they are growing the stag keeps to the low woods, and first seeks the high-lying forests when they are completed. He only leaves the forest for any length of time during the breeding season, but, wherever possible, comes to the field for a short time every evening to feed on cabbages, peas, beans, young corn, clover, lupines, grass, etc. Turnips, carrots, and potatoes, dug out of the ground by the fore legs, are also devoured. In this way red deer do a great deal of damage, not only directly in feeding, but also, to a larger extent, by trampling down the crops. In autumn and winter they chiefly feed on acorns, beechnuts, buds and young shoots of various trees. They also peel the bark from young trees, and often cause damage while rubbing the remains of the velvet from their antlers. Red deer are injurious to agriculture and forestry. Suitable fencing of fields, gardens, etc., to be protected.

The =Roebuck= (_Cervus capreolus_) measures up to three and a half feet long, and about two feet high. Antlers (Fig. 27) only slightly branched, and rough all over; beams and branches cylindrical. No brow-tynes, and usually only three branches. Tail extremely small and inconspicuous. Legs long and slender. Summer coat greyish brown, passing over to a reddish tint; the longer winter coat brownish grey. A whitish patch on the rump. The young (“fawns”) have at first white spots on a brownish ground.

Breeding season in August. The female (“doe”) brings forth her two fawns in May or June. The roebuck keeps principally to the lower and middle forests, especially in places where glades, rich in grass and herbage, and cornfields or meadows alternate with woodland. In the evening it comes out of the cover to eat in the fields and meadows; towards morning it withdraws again. The roebuck devours both young corn and corn in the ear; also ears of millet, beans, peas, clover, and lupines. It does not appear to touch potatoes and turnips. The bucks in particular do much mischief by trampling about in cornfields.

The =Fallow Deer= (_Cervus dama_) is about four feet long and three feet high; antlers rough and cylindrical only towards the root, with tolerably smooth, flat, shovel-like ends. Old individuals are pale brown, the summer coat is reddish and brightly spotted; belly whitish; a white patch on the tail. The young have sharply marked bright spots. In its habits this non-indigenous species agrees in many respects with the red deer, but changes its abode less. Towards evening it eagerly leaves the forest in order to seek its food in the cornfields. As the fallow deer lives in large herds its trampling does much damage.

ORDER: =Multungula= or =Pachydermata= (MANY-HOOFED OR THICK-SKINNED MAMMALS).

Non-ruminating hoofed animals with thick, often callous, naked, or scantily haired, frequently bristly skin and with three to five toes, which, though they are not all developed to the same extent, are yet never rudimentary. The various species are very unlike one another as to food and dentition. Here belong domesticated swine, and a single species—formerly occurring wild in Britain—

The =Wild Boar= (_Sus scrofa_). On each foot four toes, of which the two hinder are small and do not usually touch the ground. The wild boar agrees in the general conformation of its body with the common domesticated swine. Six incisors in upper and lower jaw; the lower ones forwardly directed. The canines, which are more developed in boars than sows, curve outwards and upwards in both jaws as “tusks.” On each side of each jaw seven tuberculated back teeth completely covered with enamel. Length of the body 5 feet 10 inches; length of tail 1 foot 8 inches. Colour: black and rusty brown. The young ones are white, spotted and striped with dark brown. The wild boar likes damp, swampy, but at the same time thickly overgrown districts, where it remains hidden in the day, only seeking the fields and meadows when it has become dark and quite still. It then chiefly feeds on turnips, carrots, and potatoes, rooting them out of the ground; it also devours leguminous crops and grain, but treads down far more of these plants than it eats. Besides this, it also feeds on acorns, beechnuts, hazel-nuts, and truffles. The wild boar does some service by devouring snails, worms, insect larvæ living in the soil, and also the pupæ of destructive species of caterpillars, which occur in the same situation; also voles. Thick hedges, in order to protect the corn from injury.

ORDER: Solidungula (SINGLE-HOOFED MAMMALS),

to which the horse and the ass belong, need not be dealt with here; still less the other orders enumerated on p. 23.

CLASS II.: =AVES= (BIRDS).