Элапхе тұқымдас жыландар

Genus of rat snakes

Elaphe is a genus of snakes in the family Colubridae. Elaphe is one of the main genera of the rat snakes, which are found in many regions of the northern hemisphere. Elaphe species are medium to large constrictors by nature. Based on the mitochondrial DNA analysis results, many species of Elaphe have been moved to the genera Bogertophis, Coelognathus, Gonyosoma, Orthriophis, Pantherophis, Rhinechis, Senticolis, Zamenis, and others. Nevertheless, the generic name Elaphe is still widely used.

Like most of the rat snakes, Elaphe spp. generally have slender but sturdy bodies, square heads, and extremely flat bellies. growing even as large as 2.75m (108 in). Elaphe spp. have large numbers of vertebrae, ribs, and ventral scales, but few rows of dorsal scales, which are characterized by having slight keels. In cross section, Elaphe spp. are shaped like a loaf of bread, the flat belly meeting the sides of the body at an angle. This special physical characteristic is well observed in Elaphe obsoleta (now considered Pantherophis obsoletus), whose belly scales curve upward. The curving of the ventral scales gives them better traction for tree climbing. The color and pattern of Elaphe spp. are quite variable and hard to generalize. In addition, Elaphe spp. have equal and smooth maxillary teeth. but some species, such as E. guttata (now considered Pantherophis guttatus), live up to 23 years in captivity. However, other species choose to hibernate in rotting logs, roots of trees, and hollow spaces in elevated tree trunks. Some snakes that live close to human communities even hibernate in old wells and barns. Most members of the genus Elaphe start their hibernation in October and emerge again the next spring. The length of the hibernation varies by species. Elaphe longissima, or Aesculapian snake, may hibernate from October to May, Species such as black rat snakes, or E. obsoleta, hibernate with other rat snakes and/or many other snake species, most notably timber rattlesnakes, racers, and bull snakes.

E. obsoleta generally starts to mate in late April, May, and early June after the winter hibernation. Males try to attract females with pheromones, as the females pass through their territories. Male Aesculapian snakes pursue female snakes until they can coil around them. They continue in such position, which is then followed by dancing for up to an hour before copulation, during which the male snake lines up with the female and holds her in place by wrapping his tail around hers and grasping her with his mouth. Then, the male everts one of his hemipenes into the female's cloaca. The mating process lasts from a few minutes to a few hours. After copulation, Elaphe spp. seek an appropriate place to lay the developing eggs. They usually lay eggs in the soft heart of a rotten log or in sandy soil under a rock. A good place for laying eggs is one that is damp but not wet, and warm but not hot. After laying eggs, the female snake covers them up with sand or soil, and then she leaves. A few species remain with the eggs until they hatch about 9 weeks later. Oviparous E. obsoleta lays 12–20 eggs under logs or leaves in late summer, which hatch in the fall. The adult snakes return to their hibernation dens in the late fall.

Many species of Elaphe are known for being nonaggressive and shy. They are prone to freeze their movements when they are shocked or encountering danger. This motionless response has contributed to many road kills of Elaphe. However, some Elaphe spp. tend to be more defensive if they are continually provoked. For example, Texas rat snakes, Elaphe obsoleta lindheimeri, are well known as one of the most snappy and combative rat snakes. In general, their defense system can be broken down to two levels. The first line of defense involves specific behaviors that they use to warn the intruders. One of the most common ways is by coiling their bodies and vibrating their tails, which simulates a rattle. Fox snakes, Elaphe vulpina (now considered Pantherophis vulpinus) and Elaphe gloydi (now considered Pantherophis gloydi), exemplify this type of defense mechanism; they mimic the rattling vibration of rattlesnakes when they encounter danger. Another common way of defense is by smearing a foul smelling musk on their predators. The musk is originated from the contents of the anal gland and the intestinal tract. Being constrictors, Elaphe spp. kill the prey by creating enormous pressure on the prey's chest. As they continue to coil more tightly, the pressure on the chest prevents the blood from circulating into the heart, which eventually leads to heart failure. They usually bite the prey first to maintain their grip on the prey before they start this deadly mechanism. In addition, they do not chew their food, but swallow it whole.