Hippos can recognise their friends' voices - BBC News
Hippos can recognise their friends' voices - BBC News Wild hippos honk to each other and can recognise their companions' voices, a study has found.animalhippoLINK
Hippos can recognise their friends' voices - BBC News Wild hippos honk to each other and can recognise their companions' voices, a study has found.animalhippoLINK