Whales frequently engage in breaching, propelling their bodies out of the water, creating a powerful visual and acoustic event. Understanding this behavior offers insights into the lives of these creatures.
Understanding the Act of Breaching
Breaching involves a whale launching itself partially or entirely out of the water. Whales achieve this by swimming vertically upwards from deeper water or by building speed near the surface before jerking sharply upward. They use powerful tail strokes to generate the necessary propulsion. For instance, a humpback whale can reach speeds of approximately 8 meters per second (29 km/hour) to clear the water.
During a breach, a significant portion of the whale’s body, often more than 40%, clears the water. Humpback whales can propel themselves up to 40 feet (12 meters) into the air. As the whale re-enters the water, it typically lands on its back or side, creating a thunderous splash.
Interpreting the Behavior
The precise reasons for whale breaching are not fully understood, but various scientific theories suggest it serves multiple purposes. One prominent theory is that breaching acts as a form of communication among whales. The loud splash and sound generated by a breach can travel extensive distances underwater, potentially signaling a whale’s location, a warning of danger, or even important social information like mating readiness. This non-vocal signal is especially useful when visibility is low or when ocean noise might interfere with acoustic calls.
Another hypothesis suggests breaching helps whales remove parasites or other skin irritations. The forceful impact with the water upon re-entry could dislodge barnacles, whale lice, or other ectoparasites that attach to their skin. While whales also use sand-rolling on the seafloor to exfoliate and remove parasites, breaching offers an additional method for maintaining skin health. Some researchers also propose that breaching is simply a form of play or social interaction. This behavior is often observed in younger whales, potentially helping them develop physical skills and coordination, or reinforcing social bonds within a group.
Breaching may also serve as a display of dominance or a warning. During mating season, male whales might breach repeatedly to attract females or deter rivals, showcasing their physical fitness and stamina. The powerful display can establish boundaries and help reduce conflicts between competing pods.
Additionally, some theories propose that breaching allows whales to gain a better view of their surroundings, particularly in busy coastal areas, or to sense distant sounds more effectively. For certain species, the impact of a breach might disorient or stun prey, making hunting easier, though this is considered less common. Finally, some evidence suggests that breaching, especially in young whales, might contribute to the development of myoglobin levels in their muscle tissue, which is important for their diving abilities.