Melanism is rare in this snake. Such specimens are entirely black above and beneath (var. niger, Nikolsky), or blackish-grey to black above, dark grey beneath (var. subgriseus, Werner), the angular line on each side of the belly often remaining light. An albino found near Vienna has been described as pale orange-yellow above, with small white spots; pupil and tongue red.
Size.—Grows to 6 feet. Specimens over 41⁄2 feet are, however, very rarely met with.
Distribution.—Generally distributed over the greater part of Austria, Italy, with Sardinia and Sicily, and the whole of South-Eastern Europe, this snake has a very broken range in France, Switzerland, Germany, and is found, quite isolated, as far north as Denmark and Poland. According to Segerus, quoted by Lacepède, it used to be quite common near Copenhagen at the end of the eighteenth century, but it is now much rarer. Its northern limit in France is in Southern Brittany, the Department Orne, and the Forest of Fontainebleau; in Germany, Schlangenbad, near Wiesbaden, perhaps also Baden-Baden and Treves. It is on record from Southern Spain. Its discontinuous distribution in Central Europe, and its presence in various localities near former Roman thermal stations, has been ascribed to its introduction from Italy as an inmate of the temples erected to Æsculapius; but I am more inclined to look upon its sporadic occurrence in the North as the indication of a once more widely distributed species now in process of extinction over part of its range.
In Asia the Æsculapian Snake is only found in Transcaucasia. It occurs in the mountains as well as in the plain, being recorded from 5,200 feet altitude in the Tyrol, 3,200 feet in the Apennines.
Habits.—The Æsculapian Snake lives in woods; among shrubby vegetation; in meadows, where it is often found under haystacks; occasionally about old walls. It climbs well, and often ascends trees. Although a good swimmer, it seldom enters the water of its own accord. It feeds chiefly on small mammals, occasionally on birds and their eggs, and lizards. Specimens which I kept in confinement fed on mice only, refusing sparrows and lizards. Very savage when fresh caught, most individuals soon become tame, and like being handled by people to whom they are accustomed, although still resenting the intrusion of strangers. However, this snake never becomes so thoroughly domesticated as the Smooth Snake, and cannot be trained to take food from the hand, according to R. Rollinat, who has devoted many years to experiments on the taming of reptiles. This observer had no difficulty in feeding his Æsculapian Snakes on mice and voles placed dead in their cage.
This snake is particularly sensitive to cold, and does not emerge until late in the spring from the vole galleries and hollow trees which constitute its winter-quarters. It also avoids excessive heat, never showing itself in the daytime during the hotter months in the South of Europe.
Reproduction.—Pairing takes place between the middle of May and the middle of June. The eggs are laid towards the end of June or in July, in holes in walls or hollow trees, under moss, sometimes even in the dung-heaps of farms, and hatch in September. According to trustworthy observers, the eggs, which measure 11⁄2 to 2 inches in length, and less than 1 inch in width, number only five or six, rarely up to eight.
The young on emerging are highly suggestive of young Grass-snakes in colour and markings, as well as in their much less slender shape as compared with the adult. They measure about 5 inches, and are at once most ready to bite.
12. Coluber leopardinus, Bonaparte
(Coluber quadrilineatus, Pallas)
The Leopard Snake
Form.—Slender. Snout obtuse, scarcely prominent. Tail about one-fifth of the total length.