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.