WHALES - SURFACING BEHAVIOUR2014
By Amelia Meyer
The surfacing behaviour of whales is fascinating, since these reveal much about the communication and nature of the animals that are usually concealed below the surface of the water. Of course, the frequency and details of the behaviour varies from one whale species to the next. Some whale species are known for being far more willing to perform on the water’s surface, while others are shy and reclusive.
Surface behaviour is used to communicate a desire to mate, show dominance, or warn of nearby dangers. Some whales also tend to be curious, wanting to peek out of the water at boats and fishermen. Therefore, they may spend extended periods of time at the surface simply to have a look at these ‘foreign’ bodies.
This behaviour involves the whale lifting its head partially out of the water, exposing its rostrum and head for an extended period of time. The eyes are kept slightly above or below the water line so that it is able to see around it. This is a slow, controlled process. It remains at the water’s surface by relying on its natural buoyancy, rather than by actively swimming. The focus of the whale during spyhopping is, generally, on a boat on the water’s surface, and not on other whales in the water. However, spyhopping is sometimes used to watch for predators inside of the water while breathing at its surface.
Sometimes called slapping, lobtailing refers to the whale’s lifting its pectoral flippers or tail fin out of the water and slapping it on the surface. This generates an audible splash. Most whales use their flukes (tail fins) by positioning the entire body downwards in the water, exposing only their tail above the water. This action is common amongst Sperm, Grey, Right and Humpback whales. Although the lobtailing can be heard by humans on the surface of the water, the sound of the slap can also carry for hundreds of metres below the water’s surface. It is an effective way to communicate aggression or warn other whales of danger.
Breaching is when the whale intentionally leaps to expose at least 40% of its body out of the water. Less than that is considered to be a lunge and is not always intentional (caused, perhaps, by the whale’s swimming rapidly upwards in pursuit of prey and naturally exiting the water). Different whales breach in different ways. For example, Sperm Whales start their ascent from deep down, swimming rapidly towards the water’s surface. The Humpback Whale, on the other hand, swims close to the surface of the water in a horizontal position, and then jerks upwards with massive effort to leave the water. Whales will usually perform a series of breaches. This behaviour communicates aggressions or indicates a desire to mate.
This is a restful behaviour that involves lying quite still on the ocean’s surface with the dorsal fin and parts of the back exposed. There is no intentional forward movement. Right Whales are known for this behaviour.
The peduncle of the animal refers to the muscular point at which the tail fin connects to the body. A peduncle throw is typical amongst Humpback Whales, and involves a forceful twist and whip while rotating into the water. The heady is pivoted downwards, while the sizeable pectoral fins are used for leverage, thrusting the tail upwards and sideways out of the water. As the peduncle hits the water, it makes an enormous, impressive splash. This is an aggressive behaviour that is common amongst the females wanting to mate, the challenging males, and the escorts.