Some species of crocodiles possess a surprisingly rapid, specialized gait, often described as a gallop or a bound. This powerful, asymmetrical motion allows them to achieve bursts of speed on land. This ability is not universal across all 27 crocodilian species, which include true crocodiles, alligators, caimans, and gharials. Instead, it is a unique adaptation seen primarily in a specific group of crocodiles.
The Specific Crocodilian Species That Gallop
The Cuban Crocodile (Crocodylus rhombifer) is the species most frequently associated with this bounding motion and is the largest crocodile capable of performing the gait. Its relatively longer and more upright limbs contribute to its terrestrial athleticism. The Australian Freshwater Crocodile (Crocodylus johnstoni) is also known for its bounding ability.
Recent research suggests the ability is more widespread among the Crocodylus genus than previously thought. The dwarf crocodile (Osteolaemus tetraspis), the American crocodile (Crocodylus acutus), and the Philippine crocodile (Crocodylus mindorensis) have all been documented using this high-speed movement. The smaller body size of many of these species may contribute to their higher likelihood of employing this specialized, high-energy gait.
Understanding the Mechanics of the Bounding Gait
The gallop or bounding motion is a distinct, asymmetrical gait that differs significantly from the standard “belly crawl” or the more efficient “high walk.” The high walk is a terrestrial movement where the animal lifts its body off the ground, using a steady, alternating sequence of foot strikes. The bounding gait, by contrast, is essentially a series of powerful leaps.
During a bound, the front legs move almost simultaneously, followed immediately by the simultaneous push-off of the hind legs, resulting in a distinct vertical movement. In a true gallop, the four limbs hit the ground in a four-beat sequence, but the movement remains highly asymmetrical. This asymmetrical limb movement provides a longer stride frequency than the simple trot used by alligators and caimans. Crocodiles capable of this movement possess muscle bundles in the forelimbs and chest that are longer and thinner than those found in their non-galloping relatives, enabling quicker limb cycling.
Why and When Crocodiles Choose to Gallop
This high-speed terrestrial locomotion is an energetically expensive movement, meaning it requires a significant burst of energy and cannot be sustained for long distances. The gallop is employed primarily as a short-burst mechanism for rapid acceleration and escape. It is most often observed when a crocodile is startled or feels threatened, using the speed to quickly flee danger or to cross open ground to reach the safety of water.
The bounding gait provides smaller crocodiles with better maneuverability and acceleration compared to their larger, non-galloping relatives. When galloping, crocodiles can achieve average top speeds approaching 18 kilometers per hour (11 miles per hour) over short distances. The motion is not used for hunting, as crocodilians are ambush predators that rely on stealth and a quick initial strike rather than prolonged chases on land.