Lizards, a diverse group of reptiles, inhabit nearly every corner of the globe, from arid deserts to lush rainforests. While often pictured basking on rocks or scurrying across dry terrain, their relationship with water is more varied than commonly perceived. Many species exhibit surprising aquatic abilities, challenging the notion that all lizards are strictly land-dwelling creatures.
Understanding Lizard Behavior in Water
The ability of lizards to navigate water is not uniform across all species, varying significantly based on their evolutionary history and environmental context; some are highly specialized for aquatic life, while others are less adept and may only enter water under specific circumstances. For instance, while a desert-dwelling gecko might avoid water, certain monitor lizards are proficient swimmers. Many lizards can swim for short distances if necessary, but they are not designed to live in water permanently.
Lizard Species Known for Swimming
Several lizard species are recognized for their strong swimming capabilities. The marine iguana (Amblyrhynchus cristatus), found exclusively in the Galápagos Islands, is the only lizard that forages in the ocean, diving to depths of over 65 feet for algae. Water monitors (Varanus salvator), native to South and Southeast Asia, are powerful swimmers, spending considerable time in aquatic environments where they hunt and evade predators. The basilisk lizard, also known as the “Jesus Christ lizard,” is famous for its unique ability to run across the surface of water, a behavior primarily a means of escape involving rapid leg movements and tail undulation. Other species, such as certain types of skinks, anoles, and the Chinese crocodile lizard, are semi-aquatic, frequently found near water bodies and capable of swimming effectively.
Adaptations for Aquatic Life
Lizards that are proficient swimmers often possess specific physical and physiological adaptations that facilitate their movement and survival in water. Many aquatic species, like marine iguanas and water monitors, have laterally compressed or flattened tails that act as rudders and provide powerful propulsion through water. Some lizards exhibit webbed feet, which increase the surface area for paddling and enhance swimming efficiency. Specialized nostrils that can close, or the ability to hold breath for extended periods, are common adaptations among aquatic lizards; for example, some anole lizards can survive underwater for up to 20 minutes by trapping an air bubble on their snout, allowing them to re-breathe exhaled air. Their skin is also often designed to resist water absorption, and their streamlined bodies reduce drag, further aiding their aquatic prowess.
Reasons Lizards Enter Water
Lizards enter water for various strategic reasons, including predator evasion, which provides a quick escape route when threatened on land. Many species also use water for hunting aquatic prey such as fish, amphibians, or insects; water monitors, for instance, are active hunters that can chase down prey in aquatic environments. Thermoregulation is another significant reason, especially for lizards in hot climates, as soaking in water helps them cool down and regulate their body temperature. Water bodies can also serve as dispersal routes, allowing lizards to move to new territories or access isolated food sources. While some lizards may soak for hydration or during shedding, for most, entering water is a functional behavior rather than a recreational activity.