Why whales jump out of the water, or slap it with their fins

Humpback whales often leap out of the water, a behaviour known as "breaching", and slap the water with their fins or tails. These behaviours have long been mysterious

Humpback whales are extremely active above the surface. They often breach, and slap the water with either their fins and tail flukes.

Researchers now understand more about why the whales do these things. They say the behaviours are all forms of communication, as the video above explains. 

The research is published in the journal Marine Mammal Science.

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