Whales and dolphins leaping from the water, a behavior known as breaching, offers a spectacular sight. This powerful display has captivated human observers for centuries. While visually impressive, breaching is not merely an acrobatic feat; it serves a range of practical purposes in the complex lives of these intelligent creatures. The reasons behind this energetic action are varied, spanning from crucial communication to physical well-being and environmental awareness.
Communication and Social Signaling
Breaching serves as an effective method for whales and dolphins to communicate across vast underwater distances. The resounding splash created by a large whale crashing back into the water can be heard miles away, especially since sound travels much farther and faster in water than in air. For instance, humpback whales may use breaching as a long-distance signal to coordinate movements or to communicate with groups over four kilometers away.
Breaching also contributes to social interactions and dynamics within pods. It can be a way for whales to signal excitement, assert dominance, or even attract mates during breeding seasons. The impressive display of power and agility showcased through breaching might demonstrate an individual’s fitness to potential partners or rivals. Synchronized breaching among a group suggests it can be a collective display with specific social functions, reinforcing group cohesion.
Physical Maintenance and Health
Breaching also plays a role in the physical upkeep and health of whales and dolphins. The forceful impact with the water’s surface can help dislodge external organisms that attach to their skin. These include barnacles and whale lice, which can accumulate on a whale’s body and potentially increase drag or cause irritation.
Shedding dead skin cells is another aspect of physical maintenance that breaching might support. Dolphins, for example, have a high skin cell turnover rate, shedding their outer layer of skin frequently, sometimes as often as every two hours. This rapid shedding helps maintain a smooth body surface, which is beneficial for swimming efficiency by reducing drag.
Environmental Observation and Foraging
The act of breaching can provide whales and dolphins with a brief, elevated vantage point above the water’s surface. This allows them to survey their surroundings, potentially spotting prey schools or identifying environmental features. While not their primary method for observation, as spyhopping (raising the head vertically out of the water) is also used for this purpose, breaching offers a broader, albeit quicker, view.
Foraging strategies may also incorporate breaching. The shockwave created by a whale crashing down can disorient or stun fish, making them easier to catch. Some species, like humpback whales, use breaching or other percussive behaviors as part of their hunting tactics, such as corralling fish into tighter groups.
Play and Expression
Beyond the practical explanations, breaching is often observed as a form of play and expression of vitality in both whales and dolphins. These highly intelligent marine mammals are known for their complex social behaviors, and breaching can be an exuberant manifestation of their energy. Young whales, in particular, may engage in repeated breaches, which might contribute to developing their physical skills and coordination.
Breaching can also reinforce social bonds within a group, acting as a form of social play. The sheer joy and athleticism involved in propelling their massive bodies out of the water can be a display of exuberance. While the energetic cost of breaching is considerable, repeated breaches may also serve as an “honest signal” of an individual’s physical condition and strength.