Hornbills know which monkey calls to heed

The yellow-casqued hornbill, an African forest bird, can tell the difference between the alarm call that monkeys make in response to an approaching leopard, which is not a threat to the birds, and the monkey alarm triggered by a crowned eagle, which is a threat to the hornbill, researchers have found.

This makes the hornbill the first bird known to distinguish between alarm calls given by another species, says Hugo J.