House Gecko (Hemidactylus frenatus)Spanish Name: Gueco
This gecko is usually found in low elevation areas where humans live, as one might expect, on surfaces such as walls, roofs, or railings.
This species lives in regions including southern India, southern China, Malaysia, the Philippines, northern Australia, Guam, the Mediterranean, and Central America.
This reptile has small scales over most of its body that lend it a velvety texture. On its upper surfaces it is a grayish to pinkish to darker brown, occasionally with specks or stripes. The underside is pale yellow with brown specks. Some adults have pale red instead. There is a small stripe from the end of the nose through the eye area and back to the ear. At night, the overall color of the gecko becomes paler.
The house gecko can be distinguished by its foot characteristics. All its digits have non-retractable claws, divided pads, and lack toe webbing. This species also has multiple bands of relatively larger, pointed scales around the tail. One other gecko species, Hemidactylus garnotii, is difficult to distinguísh from the house gecko without a microscope to compare their scales.
Biology and Natural History
This common reptile might be seen actively hunting insects during the day, but they are more likely to be seen at night while they stalk insects crowding electric lights. They are fast animals, and have toes constructed to render them capable of running on vertical, smooth surfaces and even upside down.
One of the more talkative reptiles and certainly the most talkative lizard in Costa Rica, the house gecko is sometimes heard before it is seen, with a rapidly repeated chirp or chuck that can be loud and startling when nearby. Both sexes do this, although males do it more, particularly before they attack another male. He will also use the call to attract females.
Females may share nesting sites, but usually pairs of eggs are laid in small nooks near ceilings, beams, or under leaf litter. Females can store sperm in their body for up to 8 months before using it over multiple clutches of eggs while they are isolated from males. This ability is one reason the house gecko has been so effective at colonizing new areas. This species has managed to travel among and survive in many regions of the world. Across most of its range in the world, this gecko is generally found in human-inhabited areas.
Insects compose this small reptile’s diet, particularly those hovering near lights at night.
From snout to vent, this gecko grows to 50 mm (2 in.); total length including the tail can be 135 mm. Adult males may be slightly longer than females.
Leenders, Twan. A Guide to Amphibians and Reptiles of Costa Rica. Zona Tropical, S.A, Miami, FL, 2001.
Savage, Jay M. The Amphibians and Reptiles of Costa Rica: A Herpetofauna between two Continents, between Two Seas. The University of Chicago Press, Chicago, 2002.
-Amy Strieter, Wildlife Writer