Reptiles
Tokay Gecko
Gekko gecko · also called tokay, gekko
The tokay gecko is a big, bold, brightly spotted lizard that most people in Southeast Asia know by ear before they ever see it — its loud “to-KAY” bark echoes through houses and gardens after dark. It is a formidable little predator, a marvel of adhesive engineering, and, increasingly, a victim of its own reputation in folk medicine.
Overview
Tokay geckos live across South and Southeast Asia, in rainforest and forest but very readily in and around buildings, where they hunt insects drawn to lights and shelter in wall cavities, roof spaces, and behind furniture. They are nocturnal, solitary, and strongly territorial, with a male defending a patch of wall or tree and a small harem of females. Introduced populations have established in Florida, Hawaii, and several Caribbean and Pacific islands.
Voice and attitude
The male’s call — a loud, rhythmic “to-KAY” repeated in bouts — advertises territory and readiness to mate and gives the animal (and the whole gecko family) its name. Tokays also croak, cackle, and hiss. They are unusually aggressive for geckos: threatened, a tokay gapes, barks, and lunges, and a bite is powerful and stubbornly held.
Sticky feet
The tokay is a classic subject for studying gecko adhesion. Its toe pads carry millions of microscopic bristles (setae), each tipped with hundreds of nanoscale spatula-shaped ends. Pressed against a surface, these make so much intimate molecular contact that van der Waals forces — individually tiny — sum to an adhesion strong enough to support many times the gecko’s weight on smooth glass, yet the foot detaches cleanly with a peeling motion. Engineers have used the principle to design dry adhesives, grippers, and climbing robots.
Diet and reproduction
Tokays are ambush and active hunters of large invertebrates and small vertebrates, including other geckos, mice, and nestling birds, seizing prey in the strong jaws and shaking or crushing it. Females lay pairs of hard-shelled eggs, glued to a wall, rock, or tree, several times a year; the eggs take several months to hatch and the young are miniatures of the adults.
Threats and status
The tokay gecko is still listed as Least Concern because it is widespread and tolerant of disturbed habitat, but it is declining in many areas due to mass collection. Unfounded medical claims triggered a boom in the dried-gecko trade across Southeast Asia, with tens of millions harvested, alongside collection for the pet trade and local consumption. Populations have been hit hard in parts of Indonesia, Thailand, and the Philippines, and international trade is now regulated under CITES Appendix II.
Tokay Gecko: common questions
Why is it called a tokay gecko?
For its call. Adult males produce a loud, far-carrying territorial and mating call that sounds like "to-KAY" (or "gecko," which is also where the word "gecko" itself comes from, via Malay "gekoq"). A calling male may repeat it a dozen or more times in a bout, several times a night, and in rural Southeast Asia it is a familiar night sound of houses and gardens. Local folklore in several countries treats hearing a tokay call a certain number of times as lucky or unlucky.
How do geckos stick to walls and ceilings?
Not by suction or glue. Each toe pad is covered in millions of microscopic hair-like structures called setae, and each seta branches into hundreds of even smaller flattened tips. This creates an enormous amount of surface contact at the molecular scale, and the resulting van der Waals forces — weak attractions between molecules — add up to a very strong, dry, reversible adhesion. A tokay can hang its whole body weight from one toe on smooth glass, and detach instantly by peeling the toe up. The mechanism has inspired reusable "gecko tape" and climbing devices.
Are tokay geckos aggressive?
For a gecko, yes. Tokays are territorial and will stand their ground, opening the mouth wide, barking, and lunging, and if grabbed they deliver a hard, prolonged bite that can break skin and is difficult to make them release — sometimes requiring the gecko to be submerged in water. They are not dangerous, but they are not a beginner's pet and are usually kept for viewing rather than handling. In the wild they are shy of humans and mostly seen only at night.
Why are tokay geckos being over-collected?
A surge in demand from traditional medicine markets, particularly claims — without scientific support — that dried tokay gecko can treat asthma, diabetes, HIV, or cancer, drove huge harvesting across Southeast Asia in the 2000s and 2010s, with tens of millions of animals traded. They are also collected for the pet trade and, locally, eaten. Wild populations have crashed in parts of Indonesia, Thailand, and the Philippines, and the species was listed on CITES Appendix II in 2019 to regulate international trade.