The common house gecko (Hemidactylus frenatus) (not to be confused with Hemidactylus turcicus, the Mediterranean house gecko), is a gecko native to South and Southeast Asia. It is also known as the Asian house gecko, Pacific house gecko, wall gecko, house lizard, Tayoto or moon lizard.
Most geckos are nocturnal, hiding during the day and foraging for insects at night. They can be seen climbing walls of houses and other buildings in search of insects attracted to porch lights, and are immediately recognisable by their characteristic chirping.
They grow to a length of between 7.5–15 cm (3–6 in), and live for about 5 years. These small geckos are non-venomous and not harmful to humans. Most medium-sized to large geckos are docile, but may bite if distressed, which can pierce skin. A tropical gecko, Hemidactylus frenatus thrives in warm, humid areas where it can crawl around on rotting wood in search of the insects it eats, as well as within urban landscapes. The animal is very adaptable and may prey on insects and spiders, displacing other gecko species which are less robust or behaviourally aggressive.
Geckos are considered venomous in many parts of the world. In Southeast Asia, geckos are believed to be carriers of good omen.[citation needed] In the Philippines, geckos making a ticking sound are believed to indicate an imminent arrival of a visitor or a letter.
An elaborate system of predicting good and bad omens based on the sounds made by geckos, their movement and the rare instances when geckos fall from roofs has evolved over centuries in India.In some parts of India, the sound made by geckos is considered a bad omen; while in parts of India, Assam, West Bengal, Bangladesh and Nepal, it is considered to be an endorsement of the truthfulness of a statement made just before, because the sound "tik tik tik" resembles the expression "thik thik thik" (Assamese: ঠিক ঠিক ঠিক), which in many Indian languages (e.g. Bengali and Assamese) means "correct correct correct", i.e., a three-fold confirmation. The cry of a gecko from an east wall as one is about to embark on a journey is considered auspicious, but a cry from any other wall is supposed to be inauspicious.A gecko falling on someone's right shoulder is considered good omen, but a bad omen if it falls on the left shoulder. In Punjab, it is believed that contact with the urine of a gecko will cause leprosy. In some places in India, it is believed that watching a lizard on the eve of Dhanteras is a good omen or a sign of prosperity.
The common house gecko is by no means a misnomer, displaying a clear preference for urban environments. The synanthropic gecko displays a tendency to hunt for insects in close proximity to urban lights. They have been found in bushland, but the current evidence seems to suggest they have a preference for urban environments, with their distribution being mostly defined by areas within or in close proximity to city bound.
The common house gecko appears to prefer areas in the light which are proximal to cracks, or places to escape. Geckos without an immediate opportunity to escape potential danger display behavioural modifications to compensate for this fact, emerging later in the night and retreating earlier in the morning.Without access to the urban landscape, they appear to prefer habitat which is composed of comparatively dense forest or eucalypt woodland which is proximal to closed forest.
The selection of primarily urban habitats makes available the preferred foods of the common house gecko. The bulk of the diet of the gecko is made up of invertebrates, primarily hunted around urban structures.Primary invertebrate food sources include cockroaches, termites, some bees and wasps, butterflies, moths, flies, spiders, and several beetle groupings. There is limited evidence that cannibalism can occur in laboratory conditions, but this is yet to be observed in the wild.
The common house gecko is prolific through the tropics and subtropics. It is capable of existing in an ecologically analogous place with other Hemidactylus species. Despite being native throughout Southeast Asia, recent introductions, both deliberate and accidental, have seen them recorded in the Deep South of the United States, large parts of tropical and sub-tropical Australia, and many other countries in South and Central America, Caribbean Dominican Republic, Africa, South Asia, and the Middle East. Their capacity to withstand a wide range of latitudes is also partially facilitated by their capacity to enter a state of brumation during colder months. The prospect of increased climate change interacts synergistically with increased urbanisation, greatly increasing the prospective distribution of the common house gecko. Due to concerns over its potential capacity as an invasive species, there are efforts to limit their introduction and presence in locations where they could be a risk to native gecko species.
In Mexico, H. frenatus was first collected in Acapulco, Guerrero, in March of 1895 and found to be well established there and in the surrounding regions by the early 1940s. It was likely introduced through shipping and cargo. H. frenatus now occurs throughout the lowlands of Mexico on both the Atlantic and Pacific versants including the Yucatan Peninsula, and Baja California, with records from 21 of the 32 Mexican states. Most records of H. frenatus in Mexico are from buildings such as homes, hotels, and other structure in cities and towns, with only a few reports of the species in natural habitat, and its impact, if any, on native fauna there is unknown.
There is evidence to suggest that the presence of Hemidactylus frenatus has negatively impacted native gecko populations throughout tropical Asia, Central America and the Pacific.
Some species which have been displaced include:
Lepidodactylus lugubris
The genus Nactus on the Mascarene Islands (three species in this genus are now considered to be extinct
As an introduced species, they pose a threat through the potential introduction of new parasites and diseases, but have potential negative impacts which extend beyond this.The primary cause for concern appears to exist around their exclusionary behaviour and out-competition of other gecko species.