Thursday, May 13, 2010
Geckos are the only lizards that have a voice. Some species of geckos make a squeaking or clicking noise that sounds like “gecko,” hence their name. Most geckos are nocturnal (they are most active at night); they have large eyes and excellent vision.
Anatomy: Geckos have short, wide, fleshy toes with large, backward-curved claws. Most geckos have sticky toe pads, composed of microscopic Velcro-like hooked bristles (called setae) on the bottom of the feet; the bristles allow them to climb well, even on smooth surfaces or upside down. Desert geckos have fringed feet that let them run across sand very easily. Flying geckos (genus Ptychozoon) have wide flaps of skin extending from the abdomen and have webbed toes, legs, and tail that help them glide gracefully through the air.
Geckos range in size from 1/2 inch to about 14 inches (1.5 to 35 cm) long; the largest gecko is the tokay gecko (Gecko gecko). The wide tail stores fat. The gecko’s eyes are covered and protected by a transparent membrane; the gecko cleans this membrane with its long tongue.
Diet: Gecko are carnivores (meat-eaters). They eat mostly insects (like crickets, springtails, and cockroaches) and mealworms, but they also eat young birds, eggs, and tiny mammals, hunting for their prey at night.
Predators: Snakes are geckos’ main predators. When a gecko is caught by its tail, it releases the tail, which twitches for a while, allowing the gecko to escape capture. The gecko will later grow another tail.
Habitat: Geckos live in a variety of warm habitats, including rainforests, deserts, grasslands, and marshes. They are now found all over the world as pets (especially the tokay gecko).
Reproduction: Geckos hatch from eggs. Females usually lay 2 white, sticky eggs. The eggs are soft at first, but harden quickly. There is no parental care. Geckos will sometimes eat their own eggs.
Classification: Class Reptilia (reptiles), Order Squamata (lizards and snakes), Suborder Lacertilia (lizards), Family Gekkonidae (geckos), about 400 species.
Lizards are vertebrate animals that similar to humans have a backbone, skull and ribs. Of the 3000 plus different species of lizard that have been discovered there are considerable differences in the shape, size and lifestyle of these lizards, there are however some common characteristics that bind them together. Of their external features they all have skin, a tongue, ears, eyes, limbs and a tail.
The skin acts as a protective coating that prevents the lizard from dehydrating. The formation of the scales varies from species to species, in some it allows the lizard to change color to adapt into the environment.
Their tongues are short and fat, although chameleons and a few others have a longer tongue. The tongue works in conjunction with the Jacobson’s organ and analyses and tastes whatever comes in contact with it.
Most lizards have a visible external ear hole or opening, sometimes it is covered up by a tympanum (ear drum).
Most lizards can blink and shut their eyes, this is dissimilar to snakes who have no moveable eyelids. There are a few burrowing lizards that have no eyes at all. There are also special adaptations between species such as the gecko, which has large eyes to aid their night vision, and chameleons that have independently moving eyes.
The limbs are specialized organs and the fingers and toes are adapted according to the species and lifestyle. An example is most geckos have adhesive pads on the tips of their digits to enable them to climb many surfaces such as trees, walls and ceilings.
The tail is also used differently depending on the species, it can be used for fighting, grasping, balancing and storage of fatty deposits to name a few. The tail can be shed as a means to defend from a predator, this is a good reason why you should never pick your lizard up by it’s tail.
The lizard is equipped with organs very similar to those of mammals. They have a skull that houses their brain, lungs to breathe air just like we do, a liver to remove toxins and the alimentary canal to process its food.
Lizards are totally reliant on the external living conditions. Unlike mammals they do not have the equipment to internally generate heat, they are therefore cold-blooded, also known as ectothermic.
Lizards thermo regulate (warm up and cool down) by moving around their habitat. When it is cool in the morning they will seek out the suns rays or the heat pad or spotlight in your vivarium so they can bask in the heat and recharge their batteries. Once they reach their optimum temperature they will then move on to hunt for food and patrol their territory. On hot days they will avoid overheating by resting in the shade, cooling off in water or seeking the coolness of their retreat or burrow.