The Tokay Gecko
A mysterious creature Geckos are small to average sized lizards belonging to the family Gekkonidae which are found in warm climates throughout the world.
Geckos are unique among lizards in their vocalizations, making chirping sounds in social interactions with other geckos. The name stems from the Malay word gekoq, imitative of its cry. Geckos are unusual in other respects as well. Most geckos have no eyelids and instead have a transparent membrane which they lick to clean. Many species will, in defense, expel a foul-smelling material and feces onto their molester.
Many species have specialized toe pads that enable them to climb smooth vertical surfaces and even cross indoor ceilings with ease. These antics are well-known to people who live in warm regions of the world where several species of geckos make their home inside human habitations. These species (for example the house gecko) become part of the indoor menagerie and are seldom really discouraged because they feed on insect pests.
The Tokay Gecko (Gekko gecko), is a nocturnal arboreal gecko native to Southeast Asia and the Indo-Australian Archipelago. They are abundant, ranging from northeast India and Bangladesh, throughout Southeast Asia, to Indonesia and western New Guinea. Their native habitat is rain forest trees and cliffs, and they also frequently adapt to human habitations, roaming walls and ceilings at night in search of insect prey.
In the late 19980s and early 1990s it was introduced into Hawaii, Florida, Belize, and several Caribbean islands, where it can be considered an invasive species. It is arboreal, living on cliffs and trees; it is usual to see them inside human residences. A typical lifespan is 7-10 years. Tokay geckos are aggressive carnivores which will eat a variety of insects and even small mice.
Their aggressive behaviour can lead to attacks on other male Tokays, other gecko species, and also human handlers. Tokays are the second largest gecko species, attaining lengths of about 30-40cm (11-15 inches) for males or 20-30cm 7-11 inches) for females and weights of 150-300g (5-10oz). They are distinctive in appearance, with a bluish or grayish body sporting orange or red spots. They are renowned for their aggressive disposition and (unusually for lizards) their loud vocalizations, sometimes referred to as a bark.
Their mating call, a loud croak, is variously described as sounding like tokeh or gekk-gekk , whence both the common and the scientific name (deriving from onomatopoeic names in Malay, Sundanese or Javanese), as well as the family names Gekkonidae and the generic term gecko.
The bite of a large tokay, while unlikely to cause lasting damage to a human, is painful and can easily draw blood. Furthermore, a tokay gecko feet, and indeed most of our knowledge about these properties stems from studies of Tokays. These studies have shown that geckos can cling upside down to polished glass, and the method by which the Tokay Gecko accomplishes this is hidden in its feet. The pads at the tip of a gecko's foot are covered in microscopic hairs. Each of these hairs splits into hundreds of tips only 200 nanometers in diameter.
By using these tiny hairs that can adhere to smooth surfaces, geckos are able to support their entire body weight with a single toe. The adhesive force created by these hairs, called setae (pronounced see' tee), lining the gecko's toes is estimated to be so strong that a single seta can lift the weight of an ant. Recent experiments have shown that the grip of a typical Tokay Gecko could theoretically support a rucksack weighing 90 pounds, while suspended upside down on a ceiling. The strong adhesion is caused by an intermolecular force called Van der Waals force.
This force is weak until it gets very close to a surface. When the surface it contacts is large, it can add up to a strong attraction. Van der Waals forces occur when unbalanced electrical charges are always fluctuating and can sometimes reverse direction, but the outcome is that they draw molecules together, such as molecules in a gecko's foot and molecules on a smooth wall. To release their feet (to break the intermolecular force they curl Their toes. When a toe is at an angle of 30 degrees the binding breaks.
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