Whale behaviour
WHEN UNDER WATER, humpback whales mostly seem to move deliberately and gracefully, but above water they’re known for energetic, sometimes airborne, displays. These marine mammals can throw their massive bodies around with surprising agility, slapping, splashing and breaching. Researchers believe these behaviours often have roles in communication or mating, but sometimes they seem to be just for sheer joy. Humpbacks spend the summer months feeding on krill in the Southern Ocean, before setting off on annual migrations up Australia’s east and west coasts to breed in tropical waters. You’re most likely to see their remarkable surface acrobatics in Australian waters between May and November. 1 Breaching The whale beats its tail to launch from the water and twists its body in the air, before crashing down on the back or side, creating a huge splash with flailing pectoral fins. Individuals can breach repeatedly – this could relate to communication, dislodging skin parasites or perhaps just because it’s fun.
2 Flipper (fin) slap A pectoral fin is raised out of the water and slapped down forcibly, making a sound that can be heard for kilometres, above and below the water. It may be used by males to attract females or to communicate with other whales in the area. 3 Fluke slap The whale forcefully smacks the tail flukes down onto the water’s surface, making a loud slap, that may signal its position to other whales. This may be performed repeatedly.
4 Lateral fluke The whale display swims on its side with one tail fluke and one pectoral fin out of the water, often seen in pods of males competing for female attention. Sometimes when a humpback is resting, it may swim gently through the water on its side, slicing the surface with one tail fluke and one pectoral fin.
5 Peduncle slap/ tail throw The whale karate chop – it strikes the base of its tail (peduncle) sideways onto the water, usually an aggressive behaviour displayed by competing males. Unlike a fluke slap, a peduncle slap or tail throw is when the whale uses all of the tail (flukes and base/ peduncle) to strike the water.
6 Spy hop The whale slowly raises its head vertically out of the water, mouth closed, until the eyes are just above the waterline. This could be to see what’s happening above the surface, and may be done by individuals or groups, probably not for communication.
It is jokingly termed ‘human watching’ when observed by people from boats.