Overview
The Eastern Spiny-tailed Gecko (Strophurus williamsi), often referred to as Williams’ spiny-tailed gecko, is an extraordinary arboreal reptile endemic to the semi-arid woodlands and arid scrublands of eastern inland Australia. Belonging to the endemic Australian family Diplodactylidae, this fascinating nocturnal gecko is famous for two parallel rows of spiny tubercular scales running along its back and tail, as well as a truly bizarre defensive superpower: the ability to squirt a noxious, foul-tasting viscous fluid from specialized glands along its tail when confronted by predators.
Biology and Physical Characteristics
Strophurus williamsi is a moderately slender gecko displaying exquisite cryptic patterns of soft silver-grey to pale fawn, overlaid with intricate reticulated dark grey blotches and chevrons that mimic the rough, lichen-encrusted bark of mulga (Acacia aneura) and cypress pine. Its large, lidless eyes feature vertical pupils with intricate gold, orange, or copper reticulations encircled by a striking bright orange or yellow ring. Along each side of its spine and down the entire length of its tail runs a double row of prominent, pointed spines or tubercles. The digits terminate in expanded adhesive pads lined with subdigital lamellae, granting exceptional climbing grip on smooth bark and thin twigs.
Behavior and Ecology
Exclusively nocturnal, the eastern spiny-tailed gecko spends hot daytime hours sheltered under peeling tree bark, within dead hollow branches, or deep inside dense spinifex grass hummocks. After dusk, it emerges to hunt small nocturnal invertebrates, moving deliberately along slender outer branches where heavier predators cannot reach. If ambushed by an owl, raptor, or snake, the gecko turns its back, raises its tail vertically, and contracts specialized caudal muscle sphincters, ejecting jets of an unpleasant, sticky, ammonia-smelling liquid that repels avian and mammalian predators without inflicting permanent damage.
Conservation and Human Impact
Evaluated as Least Concern by the IUCN, Strophurus williamsi possesses a vast geographic distribution across inland Australia and maintains robust, stable populations across numerous national parks and pastoral rangelands. Major ecological threats are linked to large-scale land clearing for grain cropping in fertile inland river basins, firewood collection that eliminates hollow limbs and dead wood, and widespread overgrazing by feral goats. Because the species adapts well to remnant roadside vegetation strips, maintaining linear woodland corridors is critical for maintaining genetic flow.
Interesting Factoid
If a predator tries to attack it, the eastern spiny-tailed gecko can shoot a sticky, foul-smelling liquid out of tiny pores along its spiky tail up to a foot away, gluing feathers together and tasting so terrible that predators immediately spit the gecko out.
Last updated: October 2026