Blue whales, the largest animals on Earth, exhibit a spectacular behavior known as breaching, where they propel themselves partly or fully out of the water. While this impressive feat is a rare sight for blue whales, it is a powerful display of their immense capabilities. This article explores the mechanics of breaching, the various theories behind why whales engage in this activity, and why it is observed less frequently in blue whales compared to other species.
Understanding Breaching
Breaching describes the act of a whale launching its body out of the water, then falling back with a large splash. This maneuver requires immense power and energy, especially for an animal as massive as a blue whale, which can weigh over 150 tons. To achieve a breach, a whale typically accelerates vertically upwards from a certain depth, or moves swiftly near the surface before an upward jerk. The whale aims to clear the water with a significant portion of its body, often at a steep angle, before landing on its side or back.
A full breach occurs when more than half of the whale’s body emerges from the water, while a partial breach involves less than half. The sheer force of the whale’s re-entry creates a loud noise and a substantial splash, which can be heard both above and below the water.
Reasons for Breaching
Scientists propose several theories for why whales, including blue whales, engage in breaching behavior. One leading hypothesis suggests that breaching serves as a form of communication. The loud sound generated by a whale crashing back into the water can travel great distances underwater, potentially signaling presence, location, or even reproductive status to other whales, especially in rough seas where other vocalizations might be muffled.
Another theory posits that breaching helps whales remove external parasites like barnacles or whale lice that attach to their skin. The forceful impact with the water during a breach can dislodge these organisms, contributing to the whale’s hygiene and health. Additionally, breaching may be a form of play, particularly for younger, more energetic whales, or a display of strength and dominance, perhaps for territorial claims or attracting mates. Some researchers also suggest it could allow whales to gain a better view of their surroundings above the surface, aiding in navigation or observing potential threats.
Rarity of Blue Whale Breaching
While blue whales are capable of breaching, this behavior is observed far less frequently in them compared to other whale species, such as humpbacks or right whales. The primary reason for this rarity is likely their immense size. Launching their massive bodies, which can weigh up to 150 tons, out of the water demands an extraordinary amount of energy. The energetic cost of breaching increases significantly with body mass, making it a highly taxing activity for these giants.
Blue whales have streamlined bodies, making them less agile than stockier species like humpbacks, which are renowned for their acrobatic displays. Blue whales generally lead more solitary lives compared to highly social humpbacks, reducing the need for frequent, dramatic surface communication displays. Conserving energy is also a significant factor for blue whales, as they need to consume vast amounts of krill daily to sustain their enormous bodies.