Reptiles
Green Basilisk
Basiliscus plumifrons · also called plumed basilisk, Jesus Christ lizard, green crested basilisk
The green basilisk is a slender, crested, brilliant-green lizard of Central American rainforest, and it can do something that looks impossible: run across the top of a pond. The ability has earned basilisks the nickname “Jesus Christ lizard” throughout the region.
Overview
Green basilisks live in lowland rainforest along rivers, streams, and ponds, from Honduras and Nicaragua through Costa Rica to Panama. They are always near water, foraging on the ground and in low vegetation by day and climbing into overhanging branches to sleep. They are shy and fast, and their whole survival strategy is built around a quick escape into or across water.
Running on water
When a basilisk is startled near water, it rears up and sprints on its hind legs straight onto the surface. The trick works because of three things acting together:
- Fringed toes that unfurl on contact, spreading the lizard’s weight over a larger area.
- A slapping downstroke that pushes the foot into the water hard enough to create a momentary air-filled pocket.
- A backward power stroke for thrust, followed by lifting the foot clear before the pocket closes and drags it down.
As long as the lizard runs fast enough, the upward reaction from each slap keeps it on top. Light juveniles can cross 20 metres of open water; heavier adults get only a short distance before sinking and switching to swimming. Basilisks are also strong swimmers and can stay submerged, motionless, for up to half an hour.
Appearance
Adult males are vivid green with pale spots and carry three crests — a rounded plume on the head, a spiny “sail” along the back, and a fin along the base of the tail — used in display and to look larger. Females and juveniles are plainer, with only a small head crest.
Reproduction
Females dig a shallow nest in moist, sunlit soil and lay clutches of around 5 to 15 eggs several times a year, which hatch after about two to three months. Hatchlings are miniature adults, already able to run on water, and receive no parental care.
Status
The green basilisk is Least Concern and remains common along waterways within its range. It tolerates some habitat disturbance as long as riverside vegetation and clean water persist, so the main pressures are deforestation and stream pollution, along with collection for the pet trade, where its colour and its famous party trick make it popular.
Green Basilisk: common questions
How does a basilisk run on water?
Speed, foot shape, and a specific stride. A basilisk sprints upright on its hind legs, and each foot has long toes fringed with flaps of skin that spread on contact, increasing the surface area. The foot slaps down hard, creating an air-filled cavity, then strokes backward for propulsion, and is pulled up and forward before that cavity collapses and the foot sinks. As long as the lizard keeps its stride rate high enough, the reaction forces from the slap and stroke support its weight. Small, light juveniles can keep it up for 20 metres; heavier adults manage only a few metres before they drop in and swim.
Why is it called the "Jesus Christ lizard"?
Because it appears to walk on water. The nickname is used across Central America for basilisks, and it refers directly to the biblical account of Jesus walking on the Sea of Galilee. The lizards use the ability almost entirely to escape — a basilisk startled on a riverbank bolts across the water to the far side or to a midstream rock, putting a barrier between itself and a predator such as a snake, bird, or larger lizard.
What does the green basilisk eat?
It is an opportunistic omnivore. The bulk of the diet is insects and other invertebrates — beetles, grasshoppers, dragonflies, spiders — supplemented with small vertebrates such as lizards, frogs, and fish, and a fair amount of plant material including flowers and fallen fruit. Basilisks forage on the ground and in low vegetation near water and are active by day.
Where do basilisks sleep?
In trees and shrubs overhanging water. A basilisk climbs up to a branch a few metres above a river or pond to sleep at night, so that any disturbance — a branch shaking, a predator approaching — drops it straight into the water, where it can dive, swim, or run to safety. This escape-toward-water strategy shapes almost everything about where the lizard lives and rests.