Breakthrough for understanding whale communication

We all know that whales navigate and communicate through sound. But scientists are still trying to find out how and why some whales have developed different systems of hearing.

Researchers at the Smithsonian Institution in Washington think they've found a clue - it all depends on jaw movements and the methods whales use to catch food. And as Jane O'Brien reports, the findings are important for conservation.

Filmed by Alan McGreevy. Edited by Bill McKenna