As he seldom goes more than a couple of yards from the bank, the quiet observer may take full stock of his proceedings, for the limited range of his vision does not permit him to see you. He appears to be very buoyant in the water, swimming with his head slightly above the surface and the body spread out. Though he may walk for a time along the bottom, he never gets his fur wet. At times he makes distinct leaps out of the water, apparently after a flying insect.
His home is a burrow in the bank, and far inside the female lines a chamber with moss and fine roots, or weaves a round nest of grass and leaves where in May or June she brings forth her litter of five to eight minute blind and naked young. These develop rapidly and when they are five or six weeks old they are independent. There is probably a second brood in September. Like the other Shrews the males are great fighters.
He is found sometimes at a considerable distance from the water, apparently seeking a change of diet, or migrating to a more abundant food supply. It does not hibernate, and may be seen in winter pursuing its prey beneath the ice. Its chief enemy is the Owl, whose cast-up pellets frequently contain the skulls of Shrews.
The Water Shrew is much more local in its occurrence than are the other Shrews. With this reservation it may be said to be widely distributed throughout England, Wales, and Scotland; and in Staffordshire and Cheshire has been found at elevations of a thousand feet. It is not found either in Ireland, the Isle of Man, the Outer Hebrides, the Orkneys or Shetlands. In the Fen country it is known as the Blind-mouse.
FLYING MAMMALS: BATS
Bats (Chiroptera).
With the exception of the great class of Birds, the Bats are the only surviving backboned animals that possess the organs of true flight. Apart from this specialisation for a life in the air the Bats are very similar in their organisation to the Insectivora, and long ago Huxley pointed out that they were exceedingly modified Insectivora; but this modification marks them off sharply from their nearest allies, and the authorities have agreed that it constitutes a reason for setting them apart in a special order—the Chiroptera or wing-handed animals.
So complete has been the adaptation to an aerial life, involving both pairs of limbs, that they are no longer fitted for progression on the earth. The fingers of the hand have been so drawn out that they are longer than the forearm, and the middle finger is at least equal in length to the head and body, whilst the thumb has been converted into a hook by means of which the Bat can hang from any rough surface. Over these exaggerated finger-bones a broad web of skin has been stretched, and connected not only to the sides of the body but also to the hind legs as far as the ankle, and then nearly or quite to the tip of the slender tail. The effect of this great modification, whilst it creates a pair of great wings, is to render the hind limbs unfitted for ordinary locomotion, for these are so twisted out of the position assumed in quadrupeds that the knees are turned backwards. This is the cause of the awkward, shuffling movements of a Bat on the ground which make it quickly rise into the air or at least to climb some vertical surface.