Whales lifting their massive tails, or flukes, out of the water creates a striking and memorable image. This behavior frequently sparks curiosity about its purpose. Observing these displays offers a glimpse into the complex lives of these marine mammals and their interactions within their ocean environment.
Understanding Whale Tail Displays
Whale tail displays encompass several distinct actions. One common display is “fluking,” where a whale raises its tail vertically out of the water before beginning a deep dive. This action often provides a clear view of the underside of the fluke, which can have unique pigmentation patterns. Another is “tail lobbing,” also known as “tail slapping.” This involves the whale lifting its tail and forcefully bringing it down onto the water’s surface, creating a loud sound and a significant splash.
A more forceful display is the “peduncle throw,” sometimes called a “tail throw” or “peduncle slap.” In this behavior, a humpback whale pivots its body to thrust its entire fluke and the muscular rear portion of its torso, the peduncle, out of the water. The whale then crashes this large section of its body sideways into the water with considerable force. While visually similar, these behaviors differ in the extent of the body lifted and the direction of the subsequent impact with the water.
The Many Reasons Whales Use Their Tails
Whales employ their tails for various reasons, ranging from communication to hunting. The context of the behavior often provides clues to its meaning.
Tail displays can serve as a form of communication among whales. The loud sound generated by a tail slap can travel considerable distances underwater, acting as a signal. This signal might indicate a whale’s presence, direction, or even convey warnings to other individuals.
Whales also use their tails as part of their hunting and feeding strategies. Humpback whales, for instance, engage in “flick feeding,” where they position themselves vertically with their heads down and tails above water. They then repeatedly flick water and krill into the air, potentially stunning the small crustaceans, making them easier to consume. Killer whales also use powerful tail slaps to disorient or stun prey such as sea lions, making them more vulnerable to attack.
Tail movements can act as a warning or defensive mechanism. A forceful tail slap can deter predators like orcas or assert dominance within a group. For example, sperm whales have been observed forming a “rosette” formation with their tails fanning outwards, using defensive tail movements when threatened by orcas. In competitive situations, such as during mating season, a male whale might use a powerful tail slap to establish dominance over rivals.
Beyond practical functions, some tail displays appear to be related to social interaction and play. Young whales, in particular, are often seen engaging in tail lobbing, possibly as a form of practice or playful behavior. These displays can foster social bonding. While the precise motivation for every display is not fully understood, social context plays a significant role in interpreting these actions.
How Researchers Study Tail Behavior
Scientists use various methods to observe and interpret whale tail behaviors, contributing to our understanding of these complex actions. Observational studies from research vessels are fundamental, allowing researchers to document the types of tail displays, their frequency, and the surrounding environmental and social contexts. By carefully noting when and how these behaviors occur, scientists can begin to infer their purposes.
Photo-identification is a widely used technique, especially for species like humpback whales. The unique pigmentation patterns on the underside of a whale’s tail fluke serve as a natural “fingerprint” for individual identification. Researchers collect photographs of these flukes, which are then matched against extensive catalogs to track individual whales over time. This method helps scientists monitor migration patterns, population sizes, and the long-term behavioral trends of specific animals.
Acoustic monitoring provides another layer of insight into whale behavior. Hydrophones, which are underwater microphones, are deployed to listen for sounds produced by marine mammals. While many whale vocalizations are studied acoustically, the loud impact of tail slaps also creates distinct underwater sounds that can be recorded. Analyzing these acoustic signals helps researchers understand the communication aspects of tail displays, including how far the sounds travel and their potential role in signaling over distances.