Part 7

The combined length of head and body is about two inches; of the tail an inch and a half. The ears are about three-quarters of an inch in length and half an inch wide; the tragus half the length of the ear. The expanse of the wings is ten inches. The single young is born about midsummer.

Bechstein's is the rarest of British bats, and so far has been recorded only from the South of England, the localities being the New Forest, Isle of Wight, Sussex, Berkshire, and Oxfordshire. Our knowledge of its habits is derived chiefly from the Continent, where it flies about woods, orchards, and the neighbourhood of dwellings, coming out from its retreat late in the evening and flying slowly and low over lanes and woodland roads, but only in calm weather. It is restricted to Central and Southern Europe.

*Daubenton's Bat* (Myotis daubentonii, Kuhl).

Daubenton's or the Water Bat was formerly considered one of our rarest Bats, but is known now to be one of the most widely distributed and plentiful species. It had probably been mistaken for the Common Bat or Pipistrelle to which it comes near in point of size, though its habits are different. It keeps close to the water, especially to some alder-sheltered pool in the river where there are plenty of caddis-flies and other insects. There from an hour before sunset it flies slowly in circles, frequently dipping its muzzle into the water to pick up surface insects. In such places the evening fly-fisher sometimes finds this Bat caught on his hook. It appears to be on the wing all night. It was probably to this Bat that Gilbert White referred in his eleventh letter to Pennant, when he said: "As I was going, some years ago, pretty late, in a boat from Richmond to Sunbury, on a warm summer's evening, I think I saw myriads of Bats between the two places; the air swarmed with them all along the Thames, so that hundreds were in sight at a time." This was long before it had been distinguished as a distinct species, and when it would probably have been regarded as the Common Bat.

It is clothed with short, dense fur, of a grizzled warm brown colour on the upper parts, and lighter brown or buffy grey, sometimes so pale as to show a distinct line of separation along the sides from the angle of the lips to the thigh. The face is dusky, and the ears and wing membrane are of a reddish dusky tint. The interfemoral membrane is whitish below, and there are whitish hairs on the toes. The membrane arises from the middle of the foot.

In size it is a little larger than the Whiskered Bat and the Common Bat, but smaller than Leisler's Bat. The head and body measure about two inches, the tail an inch and a quarter, the ear half an inch; the wing expanse is about nine inches. The foreleg and foot are conspicuously large. The ear has a rounded tip, and a shallow concavity on the upper part of the hind margin; the lance-shaped tragus is about half the length of the ear. The spur or calcar of the foot extends three-fourths of the distance between the foot and the tail. The last two joints of the latter usually extend beyond the membrane.

For its daytime rest it retires to crevices in trees, walls, caves or roofs, often in numbers, but its resorts have not the evil smell that such places frequently give off. It has a low soft chirp, less shrill than the cry of the Common Bat. In hibernation--which extends from the end of September to about the middle of April--it is no longer sociable, but hangs alone in some dark cave.

There is a single young one, born in June or July.

Its range extends from Ireland to Asia, and from the Mediterranean to central Norway.

*Common Bat* (Vespertilio pipistrellus, Schreber)

The Common Bat is in a general sense familiar to everybody, for it may be seen in the evenings flying everywhere, even in the streets of crowded cities. Its British distribution extends from the South of England to Scotland and the Hebrides and westward to Ireland. Its wider range includes Europe and parts of Asia. It is the smallest of the British Bats.

In spite of its small size--the head and body measure little more than an inch and a half--the Common Bat is of robust build, and it has a wing expanse of over eight inches. It has a flat broad head with a blunt muzzle and wide mouth. The short, broad ears are somewhat triangular with blunt tips. The erect, slightly incurved tragus has a rounded tip which does not reach quite to half the height of the ear. There are glandular swellings on the muzzle between the nostril and the small, but rather prominent eye. The tail is little over an inch in length, and the legs also are short. The last joint of the tail is free from the membrane and prehensile, and the Bat makes use of it as a support in crawling up or down. The spur reaches more than halfway to the tail. The narrow wing is attached to the middle of the sole of the foot.

The somewhat silky fur is a reddish-brown on the upper parts, slightly paler beneath. The wing membrane and the ears are blackish.

It is a very active Bat, flying over farmyards and gardens and about houses, frequently uttering its shrill little squeak as it snaps up the flies and small beetles, pouching and eating them without alighting. It continues its flight all through the night, and has a longer period of activity than any other species, for it leaves its hibernaculum in March and does not retire until winter has begun. Even then, a moderately high midday temperature is sufficient to awaken it and bring it out for an hour's hunt. It is this habit that accounts for the letters in the daily papers from City gentlemen who report the presence of a Bat flying along Cornhill or Cheapside early in January.

It is not particular in regard to its sleeping place, and is frequently found under roofs, behind rainwater pipes and gutters, or in any crevices between woodwork and brickwork in buildings. Any regular dormitory acquires a very fetid odour from its use.

The dental formula of the Common Bat is: i 2/3, c 1/1, p 2/2, m 3/3 = 34. Schreber's name of Vespertilio pipistrellus was bestowed in 1774 and is the oldest name; in the British Museum Catalogue it is Pipistrellus pipistrellus, a combination invented by Miller in 1897.

*Serotine* (Vespertilio serotinus, Schreber).

The Serotine and the Noctule are our two largest Bats, and in the early records they were very much confused. Though similar in size, they may be known apart by the shape of the ear; in the present species oval-triangular with the tips rounded. The fur is also of a darker brown, and there are other points of difference, such as the possession of two additional teeth by the Noctule. But for a few records of its occurrence in Essex, it might be said to be restricted in Britain to that portion of England bounded by the river Thames and the English Channel. A few examples have been taken in Cornwall, and other counties in which it is found are Surrey, Hampshire, Sussex, and Kent. It occurs throughout the Isle of Wight--where it is known as Rattle-mouse--but Kent is its British metropolis, where it is the commonest Bat. It extends through Central and South Europe, from Denmark to the Mediterranean and eastward into Asia.

It has a somewhat swollen face with little hair on the front portion, save for a moustache on the upper lip; but owing to the dark skin of the face the lack of fur is not very noticeable. The dark brown fur of the upper parts is soft and dense; behind the shoulders the hairs have buffy tips. On the underside the fur is somewhat lighter. There is little extension of fur on the wing, except a line of down on the under surface of the forearm. The membrane is attached to the base of the toes. The head and body measure about three inches, and the tail slightly exceeds two inches, the last joint being quite free of the membrane. The expanse of the wings is fourteen and a half inches. There are prominent glandular swellings on the muzzle. The ear is about three-quarters of an inch long; the short tragus--less than half the length of ear--has a straight front border and a curved hind border, with rounded tip. The canines and the inner incisors of the upper jaw are noticeably large and strong. Dental formula: i 2/3, c 1/1, p 1/2, m 3/3 = 32.

The Serotine makes its appearance in public about sunset, apparently retiring early and flying again in the early morning. It frequents glades in woods, and preys upon beetles and moths. In May and June large numbers of cockchafers fall victims to it, and in July and August in Kent and Sussex it plays havoc with the local Brown-tail Moth. In the early part of its season it flies at a low height, but later it prefers an altitude between thirty and forty feet, from which, however, it frequently descends to the ground. The change is, no doubt, connected with the seasonal succession of insects with different habits. It is a sociable species, and when it retires to holes or roofs for its daytime rest it is usually in company. Its hibernation begins at the end of October. Its voice is a squeak.

* * * * *

The Parti-coloured Bat (Vespertilio murinus, Linn.) is sometimes enumerated among British Bats, but on the strength of only two specimens captured in this country, in the "thirties" of last century. As one of these was taken at Plymouth and the other at Yarmouth, it is reasonable to suppose that they were mere stragglers which had reached our shores on board ship. Had they occurred as residents their distinctive coloration--dark brown upper side mottled with yellow-brown and whitish underside--and large size, would have established their identity at once.

*Great Bat* (Nyctalus noctula, Schreber).

Though similar to the Serotine in size and to the Pipistrelle in form, the Great Bat or Noctule was recognised as a distinct species long ago. We might with great fitness call this White's Bat, for it was the Selborne naturalist who first called attention to it as a native species, under the name of altivolans, suggested by its high flight. Schreber, however, had some years previously named it noctula, basing his description upon a French specimen. White refers to it several times, and in his xxxvith letter to Pennant gives particulars which the latter included in his "British Zoology." Part of White's description is worth quoting. He says: "In the extent of their wings they measured fourteen inches and a half; and four inches and a half from the nose to the tip of the tail; their heads were large, their nostrils bilobated, their shoulders broad and muscular; and their whole bodies fleshy and plump. Nothing could be more sleek than their fur, which was of a bright chestnut colour.... They weighed each, when entire, full one ounce and one drachm. Within the ear there was somewhat of a peculiar structure that I did not understand perfectly! [? tragus] but refer it to the observation of the curious anatomist. These creatures sent forth a very rancid and offensive smell."

To add to White's description, it may be said that the general form is robust and heavy, the forearm massive, the wing long and slender, its narrowness being due to the shortness of the fifth finger. The lower leg is short and thick and the foot broad and powerful. The muzzle is broad and has a glandular swelling between eye and nostril. The nostrils project forward and outward and there is a distinct concavity between the two crescent-shaped orifices. The ear is short--when flattened it is broader than long--with the front border rounded to the tip; its inner surface covered with short hairs. The ears are far apart. There is a very short, downy, bow-shaped tragus, broader above than below. The long, soft, golden-brown fur is abundant, and extends over the face and a short distance over the wing; it is paler and duller on the lower parts. On the underside there is a narrow band of fur below the arm bones. The last joint of the tail is free. The membrane and ears are blackish.

The dentition is: i 2/3, c 1/1, p 2/2, m 3/3 = 34.

The Great Bat, as one would expect from the shape of the wings, has a quick, dashing flight reminding one of that of the Swifts, with which, indeed, it may be seen high in the air hawking for the same prey. It often glides down obliquely on expanded wings. It flies at twilight and again at dawn, as well as in the daytime occasionally. It has a shrill, clear, cricket-like voice.

Mr. C. B. Moffat says they "cram themselves to bursting point either once or twice in the twenty-four hours, during a seventy minutes career of mad excitement among the twilight-flying beetles and gnats." They also take moths and other insects; but in captivity they have resolutely refused to eat such "warningly coloured" species as the Cinnabar and Magpie moths. It is proved that at one meal they will consume food equal to a fourth of their own weight. When one considers the lightness of insects the amount of good these purely insectivorous creatures effect is obvious.