Elaphe schrenckii
Elaphe schrenckii is a species of nonvenomous snake in the family Colubridae. The species is indigenous to Northeast Asia. Common names. Common names for "E. schrenckii" include Amur rat snake, Manchurian black racer, Manchurian black water snake, Russian rat snake, Schrenck's rat snake, and Siberian rat snake. Taxonomy. "E. schrenckii" is very similar to the Korean rat snake, "E. anomala", which was once thought to be a subspecies of "E. schrenckii" and was classified as "E. schrenckii anomala". Etymology. The specific name, "schrenckii", is in honor of zoologist Leopold von Schrenck. Conservation. The species "E. schrenckii" has  not been assessed by the IUCN but is on the China Species Red List with a classification of "Vulnerable VU A2a". It is an officially protected species in Russia and South Korea. Geographic range. Endemic to Northeast Asia, "E. schrenckii" is found in China, Korea, Mongolia, and Russia. It occurs in Russia and China, to the east to Chabarowsk in the Amur region, west to the Chingan mountains, and north to Manchuria (Northeastern China). The common name, Russian rat snake, is misleading as only a small portion of the geographic range of "E. schrenckii" is in Russia. It has been  reported from Chinese provinces of Jilin, Heilongjian, and the Quingyuan area of Liaoning. (Ji Daming e.a., 1985). In the Netherlands the species occurs as an introduced exotic around Groningen airport near Eelde, where it was first seen in the mid nineteen nineties. Reportedly, pet snakes were released into the wild by someone who did not expect that they would survive the winter. However, the snakes which were hardier than expected bred, and the species is now gradually increasing its range. Habitat. As one common name, Manchurian black water snake, suggests, this species inhabits fairly moist biotopes such as forest clearings , scrub, farmland, hiding amongst cavities in trees, piles of stone or wood, and when threatened can flee up a tree or into the water. "E. schrencki" has been noted up to high in trees. This species occurs up to altitude and can live in cooler areas than many other snakes. Description. "E. schrenckii" can reach a total length (including tail) of . It is among the largest and most robust of all the rat snake species. It varies greatly in colouration, from creme saddles to dark brown saddles. Many captive bred specimens have been line bred to produce clean yellow saddles . The northern, darker, is the most common variety. This species has 200-236 ventral scales, 55-78 subcaudal scales, and 21-23 rows of dorsal scales. Behavior. "E. schrenckii" feeds primarily on small mammals, birds, and bird eggs. It is often found in wetlands, but also found in a wide variety of mainly moist environments such as scrub land, farmland, river banks, swamp land, gardens, stones, log piles, forests, and up in trees. The Manchurian black water snake is an excellent swimmer (hence one common name) and is a very good climber, as it is semi-arboreal. This snake is  believed to be mostly crepuscular (active only at dawn and dusk). Reproduction. Adult females of "E. schrenckii" lay from 6 to 30 eggs in June or July. They may retain their eggs for a time, as they may deposit them in a well-advanced state. Eggs usually hatch within 40 days.