The dubious dtella, native Australian house gecko, or dubious four-clawed gecko (Gehyra dubia ) is a species of gecko in the genus Gehyra, native to Northeastern Australia (Queensland and northern New South Wales as well as islands of the Great Barrier Reef and the Torres Strait). The lizard is found in a variety of habitats, including acacia and eucalyptus woodlands, and in human-developed habitats, such as house walls in urban areas. Its urban presence makes it known as a common house gecko in Queensland. These geckos are often confused with the Asian common house gecko, which was introduced to Australia from Indonesia, but G. dubia has distinct rounded feet and quieter calls.
Gehyra dubia is a small gecko; its snout-to-vent length ranges up to 6 cm, and its tail length ranging up to 14 cm. Body size does not vary significantly between the sexes. While resting, they are typically a dull gray-brown color and carry dark spots all over the dorsal side. It has a slight camouflage ability, and often changes to a lighter brown. When foraging, they lose the spots on their back. These geckos have four limbs, each complete with five digits. On each digit is situated a circular pad, which helps them grip surfaces. This contributes to their ability to succeed in a human house as a habitat; they can grip onto ceilings and glass windows. Interestingly, G. dubia lacks a claw on its inner digits. The skin on the gecko, even its tail, is smooth. This is one of the distinctions between Gehyra dubia and other Australian gecko species. These geckos also lack eyelids and have vertical eyes like most other gecko species. Therefore, they lick their eyes with their tongues rather than blinking in order to clean them. A nocturnal advantage is that their big eyes are about 350 times more sensitive than human eyes in the dark. When in periods of stress such as a predator chase, the dubious dtella can lose its tail as a mechanism for feigning injury.
In the 1800s, G. dubia were abundant in southeast Asia, Pacific Islands, and northern Australia. Now, G. dubia is widespread across Eastern Australia only. Since it is often confused with other geckos, many reports say they are present in island archipelagos north of Australia and in New Guinea. However, scholars limit its true range to just Australia.
The dubious dtella is very adaptable and can live in a variety of habitats, including woodlands, dry forests, and shrublands. However, they are mainly arboreal and usually prefer a dry habitat. For that reason, G. dubia is not prevalent in rainforest areas. Its broad niche contributes to the prevalence of G. dubia in Queensland homes, as houses provide a hiding from predators and increased access to prey. For this reason, they are frequently found at night on walls, floors, or windowpanes. They also enjoy foraging dispersed prey at night time, which would explain their presence in the Australian bush.
Native house geckos are nocturnal, and therefore mostly feed and forage in the nighttime. Although G. dubia are habitat generalists, they are dietary specialists. The diet of G. dubia consists mainly of invertebrates. They have a preference for larger invertebrates such as scorpions, spiders, and beetles. When G. dubia stomachs were examined, all specimens were demonstrated to have been digesting cockroaches or spiders, as these invertebrates stay in the stomach longer before digestion. The abundance of night insects, such as ones crowding around light in human settlements, could explain the prevalence of G. gubia in the households. Their preference for dark, dry spaces leaves explains their often being found in dimly lit corners of houses at night Furthermore G. dubia has been known to feed on plant nectar and sap as well. Sap is a fast and easily digestible source of sugar and nutrients, so these arboreal animals spend a lot of time licking the sap of the Acacia tree. Diet does not vary significantly between the sexes.
G. dubia is oviparous, meaning they reproduce by laying eggs. A typical female clutch consists of two eggs. Egg size increases as maternal body size increases. Since G. dubia are prevalent in human houses, eggs are often laid in clutches of two in crevices where the geckos reside. G. dubia lays its eggs and breeds during the wet season. They make mating chirps during breeding season, especially to please a mate. Chirping calls are related to mate signaling and used by males to call for females.
G. dubia is listed under Least Concern by the IUCN Red List, probably due to their generalist status. Their ability to thrive in an urban environment has led to constant population size for the species.
