Snakes Including an Introduction, Its Physical Characteristics,

¶ … snakes including an introduction, its physical characteristics, locomotion, behavior, and reproduction.

Snakes are cold-blooded, legless animals that are grouped under the category of reptiles. They are closely related to lizards and are believed to have evolved from them. Scientists classify snakes in the squamata order of reptiles and the sub-order of serpentes. There are over 2,500 species of snakes and they are found on every continent on the Earth except Antarctica. They may range in size from just 5 inches in length (the Texas blind snake) to over 30 feet (the anaconda). Despite being cold-blooded, snakes can survive in a wide variety of environment ranging from the hottest deserts, the depths of the oceans to the extreme cold of North Europe. (Shine, 2005)

Physical Characteristics

All snakes have a long, flexible body covered with overlapping scales whose main function is to prevent water loss. The skin of the snakes, shed regularly, carries color pigmentation that helps it to blend with the background. Snakes are vertebrates and have a highly flexible skeleton. The flexibility enables it to swallow much larger animals than its apparent size would warrant. Its internal organs are similar to other reptiles but have been modified to fit its peculiar elongated shape -- i.e., most of its organs are placed one behind the other. Snakes have passable vision, do not have proper ears, but can detect vibrations. Its sense of smell is highly developed as it uses its forked tongue to detect scent particles in its surroundings. An important characteristic of snakes is their ability to inject poisonous 'venom' into their prey. The venom is usually delivered into the victim by biting with their two teeth called fangs. A few snakes like the spitting Cobra, spit or eject venom in a spray, instead of biting. All snakes, however, are not venomous and in fact it is estimated that only a quarter of all snakes are actually poisonous. ("Snake," 2005; Shine 2005)

Locomotion

Snakes do not have legs but have devised an efficient way of movement. Most snakes move by alternately tightening and relaxing muscles located at the side of their bodies. This produces a lateral undulating movement, known as the serpentine movement, through which snakes can achieve speeds of up to 10 km/hr. In addition to lateral undulation, snakes are also capable of concertina movement. Such movement is used by tropical snakes for climbing trees; snakes do so by coiling their tails around a tree, hooking their necks into a higher part of the tree and pulling the rest of their bodies up behind them. The third type of locomotion used by some snakes is "side-winding." The movement is similar to lateral undulation except that in side winding, the head of the snake is thrown forward after lifting it off the ground. Some snakes use 'side winding' to move across slippery mud or loose sand use it.

Behavior

As mentioned in the introduction, snakes are cold-blooded animals and cannot generate body heat by digestion of food. However, they do need external sources of heat especially while digesting a meal or during reproduction. Hence it is not unusual to find snakes basking in the sun for long periods after devouring a meal.

To conserve heat, snakes coil up, exposing less skin to cold. In colder environments, snakes hibernate in winters hiding in deep crevices or underground shelters. Such shelters may be inhabited by a number of snakes at a time due to lack of appropriate space, but otherwise snakes like to live solitary lives.

Snakes feed on worms, insects, lizards, small mammals, birds, and frogs. Some snakes feed exclusively on other snakes or on eggs of other animals. The large pythons such as the anaconda can swallow even larger animals such as wild pigs, monkeys, and deer. They usually employ one of two methods for killing their prey: by injecting their venom or by constriction

. Smaller, agile snakes may pursue their prey while heavier snakes like the python lie in waiting and ambush their victim when they pass by. Sakes do not chew their food and swallow their food whole -- often while the victim is still alive. ("Snake," 2005)

Snakes also employ a wide-range of techniques to ward off predators who feed on them. Some snakes become absolutely motionless to escape detection. Venomous snakes sometimes have distinctive coloration such as bright yellow and orange stripes to warn attackers about their poisonous nature. Other snakes such as the rattlesnake make a hissing or a buzzing sound to frighten predators. Some snakes simply strike at their attackers, and/or display their fangs to warn them off. (Shine, 2005)