Babbler bird calls 'convey meaning'
A bird can communicate in a similar way to how humans use language, scientists have discovered.
A study of the chestnut-crowned babbler bird from Australia revealed a method of communicating that has never before been observed in animals.
The bird combines sounds in different combinations to convey meaning.
The findings could help in the understanding of how language evolved in humans, researchers report in the online journal PLOS Biology.
Co-researcher Dr Andy Russell from the University of Exeter said: "It is the first evidence outside of a human that an animal can use the same meaningless sounds in different arrangements to generate new meaning.
"It's a very basic form of word generation - I'd be amazed if other animals can't do this too."
Babbler birds were found to combine two sounds (known as A and B) to generate calls associated with specific behaviours.
In flight, they used an "A-B" call to make their whereabouts known, but when alerting chicks to food they combined the sounds differently to make "B-A-B".
The birds seemed to understand the meaning of the calls.
When the feeding call was played back to them, they looked at nests, while when they heard a flight call they looked at the sky.
Co-researcher Dr Simon Townsend, from the University of Zurich, said: "Although the two babbler bird calls are structurally very similar, they are produced in totally different behavioural contexts and listening birds are capable of picking up on this."
The findings could aid understanding of how language evolved in the ancestors of humans, he added.