Elephants mourn. Dogs love. Why do we deny the feelings of other species?

Scientists are discovering more and more about the internal lives of animals. But what does this mean for the way humans behave?

Last week footage of five young elephants being captured in Zimbabwe to sell to zoos travelled round the world. Parks officials used helicopters to find the elephant families, shot sedatives into the young ones, then hazed away family members who came to the aid of the drugged young ones as they fell.

The film, shared exclusively with the Guardian, showed the young captives being trussed up and dragged on to trucks. In the final moments of footage, two men repeatedly kick a small dazed elephant in the head.