A long (up to 1,600 mm or 63″ in total length), plain green, yellow-green, or olive snake with a plain cream to light yellow underside. Young are gray to gray-green with prominent gray-brown dorsal blotches. As the snake ages the blotches begin to fade and the snakes coloration becomes more green. The dorsal blotches eventually disappear into the green background coloration. The dorsal scales are mildly keeled. The head is relatively long and narrow and is clearly distinct from the thin neck. The pupils are round. Females usually grow to a longer length than males.
This snake is found in the Baboquivari, Pajarito, Atascosa, Santa Rita, Empire, Patagonia, Chiricahua, Swisshelm, Pedregosa, and Peloncillo mountains of southeastern Arizona. In our state it occurs at elevations ranging from about 3,600′ to exposed, south-facing slopes at about 8,000′.
The Green Ratsnake is primarily an inhabitant of Madrean Evergreen Woodland and the upper reaches of adjoining Semidesert Grasslandcommunities. It is often encountered on relatively exposed, steep, rocky slopes and along drainages at the bases of such slopes.
Primarily diurnal and crepuscular. It may spend some time foraging in the branches of trees and bushes but it spends the majority of its time on the ground. It shelters under large rocks, boulders, rock piles, and outcroppings. In Arizona it hibernates during the cold months of late fall and winter. When encountered this snake often remains motionless, presumably to avoid detection.
This is a relatively powerful constrictor that eats small mammals, lizards, birds, and bats.
Mating takes place in spring and a clutch off up to 9 eggs is laid in late spring or early summer.