Overview
The Collared Treerunner (Plica plica) is a large, strikingly adapted arboreal iguanian lizard native to the undisturbed primary rainforests of the Amazon Basin and the Guiana Shield. Renowned for its pronounced spiny vertebral crest, moss-mimicking coloration, and distinct black neck collar, this diurnal reptile is an obligate vertical tree-trunk specialist. Spending virtually its entire life clinging to colossal buttressed rainforest trees, the species serves as a key arboreal predator of swarming tree ants and wood-boring beetles.
Biology and Physical Characteristics
Plica plica possesses a flattened body and powerfully developed limbs tipped with extremely elongated, needle-sharp claws that dig firmly into thick rainforest tree bark. Its body coloration is a masterpiece of natural camouflage: an intricate mottled tapestry of lichen-green, olive, and slate-grey that blends seamlessly with rainforest epiphytes. Around its neck sits a conspicuous double velvet-black collar lined with spiky white scales. Along the nape and spine runs a prominent, serrated crest of pointed scales that breaks up the animal’s physical outline when pressed flat against a tree trunk.
Behavior and Ecology
The collared treerunner is strictly diurnal and heliothermic, maintaining an unusual microhabitat preference: large, vertical tree trunks with diameters exceeding one meter, especially trees bearing smooth or lichen-crusted bark. It rests vertically with its head facing either upwards or downwards, alert for passing invertebrate prey. Its diet consists largely of stinging arboreal ants (including Camponotus and Cephalotes species) as well as caterpillars and bark beetles. When approached by potential predators like raptors or climbing snakes, it spirals rapidly around the trunk to keep the tree mass between itself and the threat.
Conservation and Human Impact
Evaluated as Least Concern by the IUCN, Plica plica is common throughout continuous tracts of primary Amazonian forest. However, because it relies strictly on large, mature, old-growth emergent trees, the species is highly sensitive to selective logging, clear-cutting, and habitat fragmentation. Secondary forests lacking massive canopy trees rarely support viable populations. Preserving vast, continuous tracts of unfragmented tropical rainforest preserves the tree trunk ecosystems that this specialized lizard requires.
Interesting Factoid
This lizard spends almost its entire life clinging vertically to giant jungle tree trunks—when a predator approaches, instead of running away, it executes a perfect spiral around the backside of the massive tree trunk like a tree-dwelling acrobat!
Last updated: October 2026