The animal kingdom is full of remarkable adaptations, showcasing how living organisms evolve unique strategies to navigate their environments. Some specialized abilities appear to defy typical physical laws, prompting closer examination of their underlying biological and mechanical principles. These feats highlight the diverse ways species survive and thrive.
The Lizard That Walks on Water
The lizard known for its ability to run across water is the basilisk lizard, belonging to the genus Basiliscus. This reptile has earned the popular nickname “Jesus Christ Lizard” or “Jesus Lizard” due to its ability to move across water surfaces without sinking. Several species exist within this genus, including the common basilisk (Basiliscus basiliscus) and the green basilisk (Basiliscus plumifrons).
These lizards are medium-sized, with long, slender bodies and tails that can account for a significant portion of their total length, reaching up to 75 centimeters (around 2.5 feet). Their colors range from brown and olive to vibrant green, often with distinct stripes or crests, particularly in males. The basilisk lizard is native to tropical regions of Central and South America, found from southern Mexico down to northwestern Colombia.
The Science Behind the Stride
The basilisk lizard’s ability to run on water involves specialized anatomy and rapid, precise movements. Their large hind feet are equipped with unique fringed toes that unfurl and spread out when they contact the water, increasing the surface area. This expanded foot surface helps distribute the lizard’s weight and generate the force needed to remain afloat.
The locomotion involves a three-phase sequence for each step: slap, stroke, and recovery. In the initial “slap” phase, the lizard forcefully brings its foot down onto the water’s surface at high speed, creating a downward and backward thrust. This rapid impact generates an upward force and briefly forms an air-filled cavity around the foot.
During the “stroke” phase, the foot sweeps backward and medially through the water, providing forward propulsion and additional lift. The air cavity helps reduce drag, allowing the foot to be pulled out of the water efficiently during the “recovery” phase, preparing for the next step. The lizard must maintain a high frequency of steps, up to 20 steps per second, and considerable speed (around 1.5 meters per second) to sustain this water-running behavior.
Life in the Lizard’s World
Basilisk lizards inhabit tropical rainforests near rivers, streams, and other bodies of water in Central and South America. They prefer elevations below 600 meters, thriving in warm, humid environments that offer dense vegetation and consistent rainfall. These lizards are diurnal, meaning they are active during the day, spending time foraging or basking in the sun. At night, they seek refuge and sleep in trees, up to 20 meters (66 feet) above ground.
Their diet is omnivorous, including insects like beetles and dragonflies, as well as fruits, flowers, and small vertebrates such as fish, snakes, or bird eggs. The most common reason for a basilisk lizard to run on water is to escape predators, which can include snakes, birds of prey, and other larger animals. While they are skilled water runners, they are also proficient climbers and swimmers, capable of diving and remaining submerged for up to half an hour.