LIZARDS AND SNAKES
- Lizards are relatively long-bodied reptiles usually with two pairs of legs and a tapering tail. In general, they have a small head, short neck, and long body and tail.
• Lizards and Snakes, like all reptiles, are air-breathing and generally “cold-blooded" so they need to regulate their body temperature with their surroundings. Their skin is usually covered in scales and they reproduce by laying soft, leathery eggs.
• Many of today’s lizards resemble the ancient reptiles of the dinosaur era. Their ancestors appeared on Earth over 200 million years ago.
• There are over 4600 lizard species found all over the world, including iguanas, chameleons, geckos, Gila monsters, monitors and skinks. They on every continent except Antarctica where it is too cold for them to survive
• The skin of a lizard is usually cool, dry and scaly - not slimy! Their scaly skin does not grow with their bodies. Instead, they shed, or molt, their old skin in large flakes to make way for new skin growth underneath.
- Lizards smell stuff with their tongues just like snakes. A lizard sticks out its tongue to catch scent particles in the air and then pulls back its tongue and places those particles on the roof of its mouth, where there are special sensory cells. The lizard can use these scent “clues” to find food or a mate or to detect enemies. The tongue is varied in form and structure. In some it is forked, in others, as the chameleons, club-shaped, and very extendible.
• Different lizard species have different diets.
-Some are predators that eat mammals, birds, and other reptiles.
-Some are generally vegetarian; eating leaves, fruits, and flowers.
-Two are venomous: the Gila monster and the Mexican beaded lizard. Their venom comes from saliva glands in the jaw, and the lizards chew it into the victim.
-Caiman lizards are skilled at eating snails and other shelled animals. Upon seizing a snail, the lizard raises its head and relaxes its grip, causing the snail to roll to the back of its mouth. It then bites and cracks the shell. By alternating bites and rotating the snail with it’s tongue, the lizard expels the shell pieces from it’s mouth.
-Most lizards are insect eaters, catching crickets, flies, grasshoppers, and more with long, sticky tongues or quick bites.
- Unlike snakes, most lizards have moveable eyelids just like we do, that clean and protect their eyes when they blink. But some lizards, like geckos, can’t blink! Instead, they have a clear membrane that shields their eyes from dirt and bright sun. Geckos use their tongue to clean their eyes!• Many lizards, such as iguanas, can see in color. Their colorful body parts allow them to communicate with each other and help them tell which are male and which are female.
• Lizards have visible ear openings (not ear flaps like mammals) to catch sound, and their eardrums are just below the surface of their skin. Lizards can’t hear as well as mammals, but their hearing is better than that of snakes.
• Lizards have the ability to shed their tails to escape from their predators. This action is called 'autonomy'. If a predator grabs the lizard by its tail, the tail has a weak spot that can easily come off. It can grow back over time, although the tail won’t look quite the same.
- Most lizards live on the ground, but others can be found making their home in a tree, burrow, or in the water.
-Tree dwellers have either long toes with sharp claws or short toes with wide claws. They usually have a tail that can be used for grasping thin branches.
-Lizards that live in a burrow often have smaller legs, or none at all, to help them move underground more easily.
-Lizards that live in the water like marine iguanas spend much of their lives underwater, but they do come to shore to rest on rocks and sandy beaches.
-Desert dwellers, usually sleep during the day underneath the sand and then come out when the sun has gone down and it is cooler outside.
- Snakes are limbless scaly elongated reptiles, some of which are venomous. Their long, slender bodies and lack of legs, eyelids, or earflaps distinguish snakes from all other reptiles. Lizards are similar to snakes, but with legs.
• There are over 2900 known snake species.
• Like their reptile brethren, they use the heat of the surrounding air to regulate their body temperature. A flexible body allows snakes to stretch out to warm up quickly, to curl up to conserve body heat. Snakes that live in places where it gets very cold in the winter may hibernate in deep, underground dens until spring brings warm weather again. Snakes that live in desert habitats often spend the heat of the day in burrows dug by other animals.
• Snakes are abundant in warm countries and the majority of them are harmless to man. Snakes are found living on open oceans, vast deserts and mountain regions at altitudes of over 10,000 feet, as well as in every habitat imaginable.
• Snakes range in size from the 10 cm thread snake to pythons and anacondas, which grow up to 25 feet in length.
• Snakes have dry, scaly skin made up of Keratin, the same thing that our fingernails are made of.
- A snake continues to grow its entire life, but its outer skin does not, so the snake needs to shed, or molt it’s skin at various times. About two weeks before it is ready to shed, the snake stops eating and its skin turns dull as a fluid begins to separate the old skin from the new.
“LOOK MA” NO LEGS & NO EYELIDS
- Because snakes are legless, they move by squeezing and relaxing the muscles down each side of its body to move forward, although he way they slither can vary widely.
-Special flattened scales on the underside of their bodies, called ventral scutes, give snakes traction. Snakes with scutes on just the underside of their body tend to move slower, but faster snakes also have scutes that extend up the sides of the body.
-Sea snakes have flattened tails that they use like paddles to propel them through the water.
-Some tree snakes are called flying snakes, although they don't really fly but flatten their body and spread their ribs to glide from tree to tree.
• Snakes don’t have eyelids, so they can’t blink or close their eyes to sleep and can’t see very well anyway. They seem to notice objects only if they move. Most of the time they sense their prey through vibrations caused by movement. Snakes are sensitive to vibrations, but their most acute sense is smell. Snakes also have no outer ear but they do have an inner ear and are quite capable of hearing
SNAKE DIET & HUNTING
- All snakes are strictly carnivores. They eat mammals, such as mice, rats, and rabbits, fish, frogs, or even other snakes. There are also some snakes that only eat eggs. Snakes find their prey in a variety of ways: -By sight, using heat-sensing pits on the sides of their head (these snakes are called pit vipers) or on the lips. -By sensing vibrations with their body, or "tasting" the air with their tongue to see what's nearby.
• All snakes have a special forked tongue, which helps them find out all types of information. When a snake’s tongue flicks in and out of its mouth, it is picking up scent particles in the air. A special organ in the roof of the snake’s mouth, called a Jacobson’s organ, processes the scents. The information brought in by the tongue helps the snake find food, tells it where to look for a mate, and where enemies may be hiding.
• Snakes are not generally aggressive, but they do have to protect themselves from predators. The most common means of defense is camouflage. Most snakes blend into their surroundings while some have evolved to look like another, deadlier snake. Some may fool a potential predator into thinking they are bigger or more threatening than they really are: cobras rear up and spread skin around the head and neck to create a large hood. Another trick is to open the mouth really wide to show a flash of white or color, which startles the predator and gives the snake the split second it needs to escape.
• Snakes have two main methods of catching their prey: active hunting for food or sitting in ambush, waiting for food to come to them. It's usually the larger snakes, like pythons, boas, and vipers that use the "sit-and-wait" technique,
• Most snakes are non-venomous snakes, but about one-third of them are venomous. They can strike (or reach forward quickly to grab their prey) with amazing speed.
-Non-venomous snakes either snatch and swallow prey alive or kill by constriction. Constrictors grip their prey, squeezing tighter each time the victim exhales. These constrictors feel the heart beat of the prey and constrict until it stops.
-Venomous snakes will use venom primarily to kill and subdue prey. They inject a toxic complex protein into their prey that kills or paralyzes it.
• Snakes don’t use their teeth to chew their food; instead they just swallow it whole. Amazingly, a Snake can eat prey that is up to 20% of their body size and three times bigger than their mouths as they have tendons in the mouth that can stretch to this size.
• They begin their meal by swallowing prey headfirst, holding on with sharp teeth that point backward. Their mouth bones are loosely attached to each other and to the skull, and the lower jaws have a stretchy band of skin holding them together. Their throat and body muscles help pull the prey down into the esophagus. Also, the opening to the windpipe is at the front of the upper mouth and moveable, so snakes are able to breathe while swallowing.
• If the meal is large enough, a snake can weeks or even months without the need to eat again. There have even been cases where large pythons have gone more than two years without eating.
EGGS & “THE TRUTH” ABOUT SNAKES
- Oviparous snakes lay batches of 2 to 16 eggs called a clutch, and some species can lay up to 50 or more eggs. The mother snake incubates the eggs by burying them or wrapping her body around them and shivering to generate heat. Some female snakes bear live young rather than laying eggs, Live-bearing snakes benefit more in more extreme climates and at higher altitudes where the weather is colder, because the developing young can be kept warm inside the mother's body.
Although many people are fearful of snakes, the truth is snakes don’t want anything to do with humans. They prefer to hide and only bite if they can’t get away or are startled. If you see a snake, just let it be. Chances are it will just crawl away.