Guests often ask us what the strange noises are that they sometimes here in their units at night.
These noises are made by geckos which are small lizards. The "chuck-chuck-chuck" call of these reptiles is distinctive on summer nights. Geckos are unique among lizards. What distinguishes them as a family is that they have the ability to produce sounds in social interactions with other geckos. Some species of geckos make a squeaking or clicking noise that sounds like "gecko," hence their name. Geckos are found worldwide in all the warmer regions. Some make high pitched calls, some sound like ducks, and others like barking dogs.
It is uncommon for a house in Queensland not to have at least one resident gecko!
There are many native ground and tree dwelling gecko species, but the best known geckos are the Asian House Geckos (Hemidactylus frenatus) which are widely distributed through southern Asia, and are naturalized on islands and seaports throughout much of the world's warmer oceans. The successful colonisation of Australia by Asian House Geckos has occurred through a series of invasion events separate in time and location. They were thought to have arrived firstly in Darwin in the mid 1960s. They were recorded around Cairns and Innisfail during the 1970s. The first sightings in Brisbane were in 1983 and appeared on the Sunshine Coast about 15 years ago.
The Asian House Geckos resemble many native geckos, but they are much more talkative - their 'chuck, chuck, chuck' call is distinctive. They have slightly enlarged spines scattered over their backs and arranged in bands around the original tail. Native house geckos are smooth.
These foreigners have now taken over from many of the native species and are creating havoc, and some people regard them as a pest on a scale similar to the cane toad. They cause alarms to go off, they get into air-conditioners, they cause fires from wiring they interfere with etc. We have a number of them living around our PABX system. They also are attracted to warm locations like the hotwater system. They're also messy, leaving their little "messages" all over the place ! They have adapted well to sharing our houses.
Most geckos are nocturnal (they are most active at night); they have large eyes and excellent vision. Most geckos have fused eyelids (like snakes) and are protected by a transparent membrane; the gecko cleans this membrane with its long tongue. They are pathologically shy of light and will only emerge from their shelter when it is nearly dark to hunt.
They are often seen catching moths and other insects around porches, walls and windows of houses, especially where insects are attracted to lights. The common gecko eats beetles, butterflies, moths, millipedes, crickets, spiders and cockroaches. Once a gecko sees an insect it will rush to within a short distance, then slowly stalk it to within striking distance.
Geckos range in size from 1.5 to 35 cm long; the largest gecko is the tokay gecko (Gecko gecko) which has a wide tail that stores fat.
The toes of the gecko have a special adaptation that allows them to adhere to most surfaces without the use of liquids or surface tension. The digits of their feet are adhesive because they have rows of tiny hooked bristles which allow them to climb straight up walls and even upside down across ceilings. The geckos' foot pad is a miracle of nano molecular materials engineering. If all micro hairs were engaged to the surface the gecko footpad has an attractive force estimated at over 10,000 kg per square centimetre. This is better than super glue !
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.
