An animal behaviour expert gives his view on finding that a killer whale can copy the sound 'hello'.
Complex behaviour such as regional accents and cultural food preferences in whales and dolphins seems to be linked to brain size.
Remembering a giant haunted by tragedy.
Humpback whales have been spotted fending off killer whales from attacking other species. But this kind of interspecies altruism raises an evolutionary conundrum.
No one wants animals to suffer, but it is notoriously difficult to measure their welfare.
Documentaries are fragile things, easily blown into obscurity or silenced by the sheer weight of corporate power.