Tropical House Gecko

The tropical house gecko (Hemidactylus mabouia) is a small nocturnal gecko native to sub-Saharan Africa and now established widely in tropical parts of the Americas. Adults commonly have a snout–vent length of about 4–6 cm, with large individuals approaching 6.8 cm, and weigh roughly 4–5 g. An intact tail can add a similar length, although tails are frequently lost and regenerated.

Colour varies from pale grey or beige to dark brown, often with irregular bars or blotches whose intensity can change. The skin carries rows of enlarged tubercles, the eyes are large and lidless with vertical pupils, and expanded adhesive pads beneath the toes allow the gecko to climb walls, ceilings, rocks and tree trunks. The pads bear microscopic hair-like structures called setae that provide adhesion to the surface.

Hemidactylus mabouia remains a valid species, but genetic studies have shown that the name has traditionally included a complex of deeply divergent African lineages. Analyses published in 2021 identified around 20 lineages that may represent separate species within the wider H. mabouia complex.

The widely invasive lineage, including New World populations, belongs to H. mabouia in the strict sense (sensu stricto). Formal revision of the African complex is not yet complete, so some African populations currently included under the name may eventually be assigned to other species.

In its native African range the tropical house gecko occurs in natural rocky and wooded habitats as well as around buildings, but it is exceptionally successful in towns, lodges and houses. Cracks, roofing, bark and other narrow spaces provide daytime refuges, while warm vertical surfaces are used as hunting areas after dark.

Human structures can provide particularly favourable habitat because outdoor lighting concentrates nocturnal insects at predictable sites. The species can nevertheless also persist far from buildings in suitable natural habitat.

The diet is broad and dominated by arthropods. Moths, flies, beetles, ants, termites, cockroaches, spiders and other small invertebrates are taken, with prey composition changing between habitats and seasons. Larger individuals can also consume small vertebrates, including smaller lizards.

On illuminated walls, tropical house geckos often wait close to a light source and make short, rapid attacks on insects attracted to it. This concentrates prey at predictable spots and reduces the need for active searching.

The same ability to hunt from vertical surfaces also allows geckos to exploit walls, tree trunks and other structures after dark when insects become active.

Tropical house geckos emerge after dark and spend daylight hours concealed in cracks, under bark, behind shutters, beneath roofing materials or in other narrow refuges. They can defend profitable feeding sites, particularly insect-rich illuminated walls, and aggressive encounters may include chasing, posturing and biting.

The species is also unusually vocal for a lizard. Chirps and other calls are used in social contexts, while males can produce more elaborate signals during territorial and courtship interactions. Visual postures and chemical cues also contribute to communication.

When seized or strongly threatened, the gecko can shed its tail through autotomy. The detached tail continues to move and can distract a predator while the animal escapes. A replacement tail later grows back, although its structure differs from the original.

Females have a nearly fixed clutch size of two hard-shelled eggs, although one-egg clutches occasionally occur. A study published in 2008 from southeastern Brazil found that larger females did not produce more eggs per clutch but tended to produce larger eggs. Reproduction occurred throughout the year, while females laid clutches more frequently during the wet season.

Eggs are placed in protected crevices, under bark, inside buildings or in other sheltered cavities. Several females may use the same site, creating communal egg deposits containing far more than two eggs even though each individual clutch is small.

There is no parental care after laying. Incubation is strongly temperature-dependent; eggs from the same southeastern Brazilian population hatched after 22–68 days, with an average of about 56 days. Hatchlings emerge fully mobile and begin hunting small prey independently.

Although native to Africa, H. mabouia is now one of the most widespread human-associated geckos in the tropical Americas. Transport by ships and cargo has moved geckos between ports and settlements, after which new populations have spread locally. In the United States the species is established in Florida.

Introduced populations are not confined to buildings. In Brazil the species has spread into natural habitats across many states. Competition can occur where native geckos use the same habitats and prey. Studies on Caribbean islands and other introduced sites have found substantial overlap in habitat or diet, although ecological effects vary among locations.

The tropical house gecko is classified as least concern on the IUCN Red List. It is widespread throughout its native African range and exceptionally tolerant of human-modified habitats.

Where the species has been introduced, it can compete with native geckos for food and habitat, especially on islands and in places where local species use similar resources.