rattlesnakes-e28093-us-most-dangerous-snakesThroughout the World there are many snakes whose venomous bite can be fatal to humans. In the United States, however, there are only four including; the Coral Snake, the Copperhead, the Cottonmouth Water Moccasin and the Rattlesnake.

Rattlesnake Description & Identification

Rattlesnakes come in 16 distinct varieties. There are numerous subspecies and color variations, but they are all positively identified by the jointed rattles on the tail and a triangular head.

Rattlesnakes, copperheads and cottonmouths are all pit vipers. Pit Vipers are snakes with two pits under their nostrils to detect heat, thus enabling the rattlesnake to hunt warm-blooded prey. The pits are so sensitive that the snake can determine the size of the warm-blooded animal and can even detect prey in complete darkness.

There are many species of rattlesnake and each can be identified by the variation of the pattern and color of their skin. Colors can range from shades of brown, gray and black, tones of yellow, cream, rust, olive, and light pink. A rattlesnake’s skin may contain a pattern that is banded, diamond shaped, or blotched. Some species of rattlesnake have no identifying pattern at all.

Rattlesnakes have a forked tongue that they flick up and down. The tongue picks microscopic airborne particles and gases from the air. When the tongue slips back into it’s mouth it touches a sensitive spot on the roof of their mouth called the Jacobson’s organ. This organ picks up the particles collected by the tongue and sends messages to the snakes brain identifying the scent as food, enemy, mate or other object or substance. Rattlesnakes also have external nostrils lined with olfactory cells which can pick up scent. The nostrils are mainly used for breathing.

The fork of the tongue is a directional aide. It can provide information based on which side or fork in the tongue has the strongest presence of a particular odor. This information helps the rattlesnake follow its prey or find it’s way home.

Rattlesnakes pick up vibrations through their body muscles which send sound through to their jaw bones and on to their inside ear parts. Rattlesnakes do not have outer ears and therefore rely on vibrations to pick up sound.

A snakes vision can detect objects or movement from about 40 feet away, but their vision is sharper when objects are closer. A rattlesnake’s pupils are elliptical, not round which enables the snake to see well in dim light. This is helpful for night hunting.

Rattlesnakes have the following physical characteristics:

• Broad, “triangular” head
• Eyes have verticle “cat-like” pupils
• Covered in scales that are a varitey of colors/patterns
• Scales are keeled with a raised ridge in the center of each
• Body is heavy or thick (or fat) in appearance
• Large tubular fangs in mouth that fold out when the mouth opens
• The mouth is like a hinge, opening 180 degrees
• Blunt tail with jointed rattle (Note: baby rattlesnakes don’t have rattles and some adult snakes may break or lose their rattles)
• Typically rattlesnakes range from 3′ to 4′ in length

In ideal habitats where there is a constant, abundant supply of small rodents, the rattlesnake sometimes attains a length of 5 feet, but the average adult size is between 3 and 4 feet.

Range

While most of the rattlers are concentrated in the southwestern United States, they extend north, east and south in diminishing numbers and varieties. Every contiguous state has one or more varieties of rattlesnake.

The rattlesnake is found in many different biomes ranging from along the coast at sea level, the inland prairies and desert areas to the mountains at elevations of more than 10,000 feet.

Behavior

In the northern areas of their range and at higher elevations, snakes congregate in the Fall at crevices in rocky ledges to hibernate for the winter, returning to these places annually. These spots are known as snake dens.

When temperatures begin to warm in April, snakes come out of hibernation. They remain near the den entrance for a few days, sunning themselves, then make their way to where they will spend the summer. They rarely go more than a mile from their dens.

Most snakes are secretive in their summer activities, hunting at night and remaining inactive and out of sight for days at a time during the digestive period after eating a squirrel or small rabbit. Consequently, more snakes are seen in the Spring and Fall migrations to and from their winter homes.

Rattlesnakes are cold-blooded (Ectothermic) and they rely on external sources to regulate their body temperature. When rattlesnakes are too hot they retreat into the shade or into a burrow. When a rattlesnake is too cold they sun themselves or find a surface, such as a paved road, to absorb the heat from the asphalt. It is common to find snakes on the road in the evening hours as they attempt to warm their bodies by lying on asphalt or concrete pave areas.

Life Cycle

While some types of snakes lay eggs, rattlesnakes give live birth. The rattlesnake, however, does have eggs, but the eggs are carried inside the females body. Once the eggs are fertilized they are carried for approximately 90 days. The eggs hatch inside the rattler’s body and then she gives live birth to her young. A reproduction system of this type is called ovoviviparous. The female rattler may contain from 4 to 25 eggs, from which an average of 9 or 10 hearty young are born live.

Mating usually occurs in the Spring after emerging from hybernation, but can also occur in the Fall. Rattlesnakes reach sexually maturity at 3 years of age. A female rattlesnake reproduces every two years and

During the process of mating the female rattlesnakes are passive while the male crawls on top of the female. By making jerking motions with the hind portion of his body he is able to press his tail beneath the female’s tail. The male continuously flicks his toungue throughout the mating process which can continue for several hours or more.

The young are born between August and October. The newborn rattlesnake is about 10 inches long and has a small horny button on the tip of its tail. Rattler babies have venom, short fangs and are dangerous from birth. In fact, they are more pugnacious than the adults. Although unable to make a rattling sound, the youngsters throw themselves into a defensive pose and strike repeatedly when disturbed.

Young rattlers are completely independent of the mother. They remain in the area of their birth for the first 7 to 10 days, until they shed their first baby skin and add their first rattle. The litter will begin to disperse as they venture out in search of food. Many newborn rattlesnakes do not survive their first year, either dying of hunger or being eaten by birds and animals. Even if they survive the first summer, they may perish during the first winter, if they can’t find a suitable warm crevice in which to hibernate.

If all goes well, youngsters grow rapidly. Each time they come out of hibernation, they shed their skin. With each skin shedding (molting) a new rattle appears. During the rapid growth of the first few years, they may molt three times annually. Thus, the number of rattles is not a true indicator of age. Rattles also wear out or break off, so it is unusual to find an adult snake with more than 8 or 10 rattles.

Lifespan

The average lifespan of a rattlesnake is 20 to 30 years in captivity. In the wild, the lifespan is less due to predation, disease or death by accident.

Predators

The King snake is well known for being immune to the venom of many pit vipers, including rattlesnakes. Rattlesnakes are part of the King snakes diet. Roadrunners, pigs, Hawks, Eagles and Humans are also predators to the rattlesnake.

Diet

Rattlesnakes are carnivorous. Instead of chewing their food, they swallow it whole. The size of the prey a rattlesnake selects is limited by its own ability to eat it based on it’s own size. Rattlesnakes eat lizards and small rodents such as ground squirrels, small rabbits, rats and mice, striking rather than attempting to hold their prey.

The rattlesnake first bites it’s prey to immobilize it with a toxic venom. When the hollow fangs of the rattler penetrate the victim’s flesh, venom is injected as though through twin hypodermic needles. Most small prey is immediately stunned. The venom stuns and immobilizes the prey, allowing time for the rattler to swallow the victim whole. The venom also begins the digestive process as it breaks down the tissue of the prey.

Rattlesnakes have a highly-efficient digestive system which takes a lot of metabolic energy. After a rattlesnake swallows it’s prey, they normally hide out while they digest their meal. Rattlesnakes become sluggish while digesting, a process that can take several days depending on the size of the meal. — www.desertusa.com