Forest Elephants heard not seen

This month, scientists have published an acoustic survey of elephant numbers in the Kakum Conservation Area in Ghana, west Africa. The elephant numbers there have been a mystery due to the density of the forest - you simply can't see them - yes, even something the size of an elephant!

The survey found around 300 elephants live in the conservation area's forests, but most remarkable it did so using sound not sight - the same way the elephants communicate. The survey is the first to evaluate elephant numbers in the wild by using acoustics - listening to them, instead of seeing them.

Watch the video and learn more on the BBC Earth News - click here