THE LOST VOICE

The regent honeyeater – a tiny bird found in Australian forests – has become so rare that it is forgetting how to sing its own song.

- Jo Caird

Conservation biologist Ross Crates was in the midst of designing a new monitoring programme for the Critically Endangered Regent honeyeater when he realised that something was seriously up with the way this Australian songbird was expressing itself.

As he and his colleagues in the Difficult Bird Research Group at the Australian National University toured regent breeding sites around New South Wales, Crates became aware of individual birds whose songs just didn’t sound right. Rather than singing their own songs, these regent males were making calls belonging to other species of bird.

Crates began recording the songs of every wild male regent honeyeater he came across. He was struck by what he found. “It wasn’t just one or two individuals singing weird songs. It’s a decent proportion of the wild population,” says the scientist.

He recalls one bird in particular which, over the course of a six-week observation period, didn’t sing its own song once. Instead, this individual was making the call of another Australian native songbird, called the little friarbird.

“I was thinking, this is properly weird: this is a bird that probably doesn’t even know that he’s a regent honeyeater.”

Birds singing other species’ songs is a well-observed phenomenon. There are plenty of bird species that use vocal mimicry to their benefit: by imitating the call of a predator to scare competitors away from a nest, for example, or to impress a potential mate with a wide vocal range.