The sight of dolphins leaping gracefully from the ocean is a captivating spectacle. While these aerial displays appear playful, they serve a variety of important functions for these intelligent marine mammals. Dolphins exhibit this behavior for practical reasons related to their movement, social interactions, finding food, and their physical well-being.
Efficient Travel
Dolphins often jump out of the water in a behavior known as “porpoising,” which allows them to travel efficiently at high speeds. Water creates significantly more drag than air, so by spending time airborne, dolphins reduce the resistance they encounter. This conserves energy, making it an advantageous way to cover long distances or pursue fast-moving prey. Some studies suggest that porpoising becomes energetically favorable above a certain “crossover” speed, where the reduction in water drag outweighs the energy cost of leaping.
When a dolphin porpoises, it alternates between swimming underwater and leaping into the air, minimizing the effort required for propulsion. Their streamlined bodies are adapted to reduce drag, but the density difference between water and air means moving through air is less strenuous at higher velocities. This behavior helps them maintain speed with less fatigue and aids in rapid pursuit during hunting situations.
Social Interaction and Communication
Dolphin jumps are a significant form of communication within their pods, conveying various messages to group members. The loud splash created upon re-entry into the water can be heard over considerable distances, signaling a dolphin’s presence or location to others. This is particularly useful for maintaining contact within large groups or at night when visibility is low.
These aerial displays serve several social purposes, including coordinating group movements or expressing excitement. Jumping can foster social bonds and group cohesion through synchronized behaviors. Leaps can also be a display of dominance or playful engagement among individuals, highlighting the intricate social dynamics within a pod.
Foraging and Awareness
Jumping provides dolphins with a momentary vantage point above the water, which is beneficial for foraging and surveying their surroundings. From this elevated position, they can spot schools of fish, which often appear as dark patches or are indicated by diving birds. This ability to gain an aerial perspective helps them locate potential food sources more effectively.
Dolphins also use jumps to observe their environment for navigation or to detect potential predators such as sharks. This “spy-hopping” behavior, where they lift their heads out of the water to look around, is a deliberate way to gather visual information. Some species, like dusky dolphins, even use the impact of their jumps to herd fish, disorienting prey and making them easier to capture for the group.
Physical Comfort
Dolphins sometimes jump out of the water to dislodge external parasites and other irritants from their skin. The force of hitting the water upon re-entry can help scrape off organisms like barnacles, lampreys, or remoras that may attach to their bodies. These hitchhikers can create drag, making swimming less efficient, and cause irritation or injury.
Studies have shown dolphins performing repeated leaps and forceful re-entries, sometimes coupled with spinning, specifically to remove these attached organisms. For example, a dolphin calf was observed performing numerous leaps and tail smacks to dislodge a remora. This behavior contributes to the dolphin’s overall hygiene and comfort, ensuring their skin remains clear of encumbrances.