Crocodiles, primarily aquatic reptiles, can move on land. While they spend a significant portion of their lives in water, they are well-adapted for land movement. Their ability to navigate diverse terrains is a testament to their adaptability as semi-aquatic predators. This dual capability allows them to fulfill various biological needs beyond the water’s edge.
How Crocodiles Walk
Crocodiles employ distinct gaits for terrestrial movement: the “belly crawl” and the “high walk.” The belly crawl involves the crocodile dragging its body along the ground, with its legs splayed out to the sides. This method is used for slower movements, such as entering or exiting water or navigating muddy terrain.
In contrast, the “high walk” is an elevated posture where the crocodile lifts its body and tail off the ground. Their legs are positioned more directly underneath their body, resembling a mammalian stance for efficient movement. During this gait, the crocodile’s body flexes in a side-to-side motion, with the front leg moving in concert with the opposing hind leg. The powerful tail acts as a counterbalance, aiding stability and balance.
Why Crocodiles Venture Ashore
Crocodiles come onto land for several reasons, primarily thermoregulation. As ectothermic animals, they rely on external heat sources to maintain body temperature. They bask in the sun to warm up, absorbing heat through their dark scales, which is important for metabolism and digestion. When temperatures become too high, they seek shade or return to the water to cool down, often opening their mouths similar to panting.
Terrestrial excursions are also for reproduction, with females building nests and laying eggs in sandy areas or mounds of vegetation. Beyond thermoregulation and nesting, crocodiles move between bodies of water, especially during dry seasons when water sources shrink. They also hunt prey near the water’s edge, using bursts of speed to ambush unsuspecting animals. Occasionally, they may move onto land to escape perceived threats in the water, although this is less common.
Speed and Terrestrial Movement
Despite their bulky appearance, crocodiles can exhibit bursts of speed on land over short distances. Larger species like Nile, saltwater, and American crocodiles can sprint between 15 to 22 mph (24-35 km/h) for brief periods. The Australian freshwater crocodile, a smaller species, can gallop up to 10.56 mph (17 km/h). However, these high speeds are not sustainable, with crocodiles tiring after covering 65-100 feet (20-30 meters).
While their top speeds can exceed that of an average human, crocodiles are not built for prolonged chases on land. Their terrestrial locomotion is adapted for short, explosive movements, such as ambushing prey or retreating to water when threatened. Smaller crocodiles display agility, with some capable of a gallop that resembles a horse’s. This highlights that their seemingly slow movement is often a deliberate, energy-conserving choice, rather than a limitation of their physical capabilities.