Chingchoks! The tale of a different tail

The 'house gecko' or 'wall lizard' goes by the scientific name Hemidactylus frenatus and it is one of over 1,000 species of gecko.

Its Thai name, "chingchok", comes from the sound it makes when it calls. When a sound or a thing is named for the sound that it makes (like a tuk-tuk, which makes the tuk-tuk-tuk-tuk-tuk sound), that is called an "onomatopoeia". That's interesting, as that is also how the chingchok got its English name - gecko. Perhaps their name depends on which language the chingchok speaks!

Chingchoks, or geckos, are native to Southeast Asia. However, being small, fast and great hiders with the ability to climb virtually any surface, they learned early to stow away on ships and now they live in North America, East Africa and Northern Australia.

When fully grown, they vary in size from about 7-15 cm. They also vary substantially in color, from nearly translucent to mottled brown.

Nasa climbing the walls with envy

A chingchok's foot has at least a half a million microscopic hairs (one-tenth the thickness of a human hair). The end of each hair is split into smaller hairs. At the frayed ends these smaller hairs have spatula-shaped structures - about a billion per chingchok. This spatula-shaped tip can flatten over rough or smooth surfaces and increases the area with which the hair can make contact. The chingchok's movement is accomplished by rolling and un-rolling these hairs onto the surface. Source: Dennis Kunkel Microscopy, Inc.

The most striking ability of a chingchok its ability to climb virtually anywhere on almost any surface. How geckos achieved such a feat baffled scientists for generations.

It took the powerful electron microscope to reveal the little chingchok's top secret. Chingchoks have up to 500,000 tiny hair-like structures, called setae, on each foot. Each microscopic setae has 100 and 1,000 spatulae or rounded ends. The structures are so minute that they can grab onto the hundreds of crevices in the smoothest surfaces, even glass. The discovery was so amazing that industry is trying to invent synthetic setae for a new generation of boot for Nasa's astronauts. And you thought it was just an humble house lizard.

If you take the time to observe their behavior, they even appear to pounce on insects while 'standing' upside down! Very impressive but, of course, its feet don't actually leave the ceiling or it would crash to the floor!

Lick their own eyeballs

I personally think the most remarkable characteristic of chingchoks, and most other geckos (except species like the leopard gecko Eublepharis macularius which, incidentally, doesn't use pads to climb walls either) is their ability to lick their own eyeballs! Unlike other lizards, they do not have eyelids so they often lick their eyes to keep them clean. Go on! You try it.

Chingchoks have many other unique adaptations, such as the ability to 'drop' their tails. This is a predator-avoidance reflex that often saves their lives. Should a predator, such as a bird, catch a chingchok by the tail the chingchok can simply shed it.

The tail that saved the day

The sudden detachment stimulates the nerves in the tail, which make it wriggle feverishly. The ruse leaves the bird satisfied with at least a morsel of a meal while the little chingchok scampers for cover. Amazingly, the tail always grows back, but it isn't uncommon to see a tailless chingchok - evidence that he has had a recent close encounter!

You may also see chingchoks with a lump around the top of their tail, indicating that it has previously lost one during its life and a newly grown tail has replaced the missing one. The only other types of lizard to have this adaptation are the skinks, of which there are also many in Thailand.

Love and marriage

House geckos have a lifespan of up to 5 years and breed generally between May and August. They lay clutches of 2 soft eggs which quickly harden which have a sticky coating that enables them to lay their eggs in cracks in walls, under logs or occasionally in large leaves. As with most geckos, they have mating rituals and courtship rituals, and the males often fight.

Some gecko species only have females in the population and reproduce by a process called parthenogenesis. This means that the females double their sex chromosomes, giving their eggs a complete set of chromosomes and therefore producing clones of the mother gecko.

Chingchoks eat many types of insects, including insects that are bigger than the chingchok's head! This flexibility in their diet makes them extremely hardy and adaptable. As a result, they often out-compete native species in the places the chingchok has been introduced.

They are pretty smart, too. Instead of hunting insects, chingchoks station themselves near a bright light and let the unwitting insects come to them. Unlimited neon lights in Bangkok serve as buffet tables to chingchoks. INSECT Chingchoks also eat disease-carrying mosquitoes, so they deserve our respect.

Next time you see a chingchok, observe its wonderful behavior for a while. They truly are remarkable and highly entertaining animals. The Crocodile Hunter? I'd rather be a Chingchok Hunter any day!

David Canavan has an MSc in Behavioural Ecology and teaches science, maths and ICT at Garden International School. David is fascinated by science and loves animals, especially the dangerous kind; the more dangerous the better. You may contact David at davidc@gardenbangkok.com .