We have three other representatives of the genus Myotis, which is probably the largest as it is the most widely distributed of all the genera of Bats. They are all of slender, delicate form, which is seen most clearly in the shape of the skull, the muzzle, the ear and its tragus. They agree also in having thirty-eight teeth—six more than in the Horse-shoe Bat. The dental formula of all the members of the genus is: i 2/3, c 1/1, p 3/3, m 3/3 = 38.
Red-grey Bat (Myotis nattereri, Kuhl).
The Red-grey or Natterer's Bat is somewhat larger than the Whiskered Bat, the head and body measuring about an inch and three-quarters, but the tail is relatively shorter, being only an inch and a half. It has the longest wings of our species of Myotis, their expanse being equal to eleven inches and a quarter.
The long, soft and dense fur is of a greyish-brown colour above and whitish on the underside. The wing membranes are dusky. It has a small head, with a narrow muzzle which is naked at the tip and slightly overhangs the lower jaw. The face is so densely covered with fur that the small eyes are hidden. There is also a moustache, and above the lips on each side is a prominent gland. The large oval ear is notched on the outer margin above the middle, and the long slender tragus is more than half the length of the ear, ending in a long, very slender point. The wing membrane extends to the base of the outer toe, and the interfemoral membrane is distinctly fringed with stiff hairs along its lower edge. The tail, which is carried extended behind, is slightly less than the head and body in length.
The Red-grey Bat shares the Whiskered Bat's partiality for wooded districts, where it may often be seen in numbers, even before sunset. Unlike the last-named species it is both sociable and gregarious, and its daytime retreat in holes in walls, hollow trees, and caverns, is shared with Bats of its own and other species. It flies low, with a slow, steady flight, and often picks flies and small moths off leaves and twigs. When so engaged like the Whiskered Bat it may be known from it by its noisy chirping. It will turn somersaults in the air in order to alight by clinging with its feet.
The solitary young one is born towards the end of June.
It does not appear to be a generally distributed species even in the South of England. Its range extends from Cornwall and the Isle of Wight to Durham and Norfolk. It also occurs in Wales and various parts of Ireland. In Scotland it has been reported from Argyll, Midlothian, and Montrose. It is a native of Central and Southern Europe, extending north to the south of Sweden.
Bechstein's Bat (Myotis bechsteinii, Kuhl).
Bechstein's Bat has a general resemblance to the Red-grey Bat, but is slightly larger, with ears almost twice the breadth of those of that species, and the feet relatively as well as actually larger. Though the skull is larger, it is actually narrower than in that species. The thin ears are relatively larger than those of any European Bat, except the Long-eared Bat, where, however, they are of quite different shape and are connected by their lower margins, whilst here their bases are widely apart. The form of the ear is like that of the Whiskered Bat; so is the tragus, and the shape of the wings.
It is covered with soft, woolly fur, which is a greyish-brown on the upper parts and buff-grey below. The membranes are dark brown; that of the wing arises from the base of the toes, and that of the interfemoral leaves the last joint of the tail free.