Critically endangered regent honeyeaters are forgetting their songs because there are few elder birds to pass them on.
The yellow-speckled, nectar-eating honeyeaters (Anthochaera phrygia), which live in Australia, learn their complex courting and territorial songs from other birds. So when populations are very small, there’s no one for young honeyeaters to learn from.
Ross Crates at the Australian National University in Canberra and his team located more than 100 male honeyeaters by combining data from a monitoring programme with public sightings reported to the conservation group BirdLife Australia. The researchers recorded the birds’ songs and compared them with historical recordings.
Overall, 27% of males sang songs that differed from the typical melodies. Some 12% had resorted to singing the songs of other bird species.
As habitat loss and competition from bigger birds threaten honeyeaters, the loss of their songs could accelerate their decline, the researchers say. Without a common song to bring them together, the birds might simply fail to mate.