It reaches a length of 1.5 m, the tail, as a rule, does not exceed 17-30 cm. The preorbital flap can sometimes be partially divided from below. The width of the intermaxillary and internasal scutes is greater than their own height. The prefrontal scutes touch the infraorbital, and the only zygomatic one has a trapezoidal shape. There are from one to three postorbital shields, eight (less often seven or nine), labial shields - 44–78, about 23–28 scales around the body. The males have 171–201 abdominal flaps, and the females 187–214. The anal shield is divided, the fourth or fifth labial - it touches the eye. Temporal flaps — 2-3 and 3-4 in each of two vertical rows. The scales on the sides of the body are smooth, and on the back - with weak ribs and two apical pores.
The species is characterized by a very variable color. The general background of the body is grayish-brownish from above, sometimes with a brown tint, with four brown longitudinal stripes (two of which extend to the tail) and with blackish spots. On the upper surface of the head is a specific pattern that changes with age. From the eyes to the neck passes a dark temporal strip. The belly is grayish or yellowish with reddish specks and sometimes dark spots. This species is known melanists . Plain-colored individuals were described as independent subspecies, but further studies found that these forms are just variants of the population variation of the species. During molting, the color changes significantly and often becomes less contrast.
It occurs from Korea , Primorye , Mongolia and Northern China through Central Asia ( Kyrgyzstan , Tajikistan , Uzbekistan , Turkmenistan ), Kazakhstan and Southern Siberia (including the island of Olkhon ), Bashkortostan , the Orenburg and Samara regions (the most northern habitat is Samara Luka ) to Ukraine , Northern Iran , Afghanistan and Transcaucasia ( Georgia , Azerbaijan , Armenia ). It does not form subspecies.
Patterned snake is well adapted for living in the most diverse conditions of several natural zones: from steppes and deserts to coniferous and mixed forests. It is found in floodplains and river valleys, tugai and reeds , in alpine meadows and outskirts of swamps , salt marshes and takyrs , dunes and rice fields, in orchards and vineyards , in juniper (juniper woodlands) and on rocky mountain slopes, rising to a height of up to 3600 m above sea level. He climbs perfectly and quickly moves both along the branches of trees and on the ground, swims and dives perfectly. As shelters, it uses voids under the roots and in the root zone of trees, hollows and cracks in the soil.
The diet includes small mammals (the main type of food in many parts of the range), birds , snakes , amphibians , fish and insects . Depending on the biotopic preferences of the snake, the composition of the feed can change in the direction of the predominance of one of their types. Eats chicks from bird clutches. In this case, the egg swallows, opening its mouth wide, and crushes the shell with the lower processes of the vertebrae (hypapophyses), pressing them on the dorsal wall of the esophagus. Cases of cannibalism are known. The victim is swallowed from the head.
Leads a daily lifestyle. Wintering lasts from September — November to March — April. In the south of the range from winter shelters appears in February. Mating takes place in April – May, but in a number of places (in Primorye, for example), the mating season lengthens until June. Usually eggs are laid in forest litter or overripe grass near ponds, rotten rot trees. In clutches from 5 to 24 eggs of different lengths (16, 30-17, 56 mm). Collective clutches of up to 120 eggs are known, of which only half sometimes survive. The incubation period lasts about a month (often reduced to almost two weeks due to the fact that the development of the embryo begins in the female’s oviducts). Young individuals appear from July to September and are 18–25 cm long and 2.8–9.3 g in weight. Adult individuals are the first to leave for wintering.
Among the enemies of the patterned snake are predatory mammals and birds (in particular, the steppe eagle ). A good defense against them is the rapid movement in shelters or on tree branches.
