Singing the Wrong Song Spells Disaster for Endangered Honeyeaters

According to recent studies from The Australian National University, the critically endangered regent honeyeater is losing its "song culture" due to the bird's steadily decreasing population (ANU).

Many birds learn to sing by associating with older birds of the same species, just as humans learn to communicate. If adults become too scarce, they will lose this capacity. And their odds of breeding are diminished if they don't learn to sing the proper tune.

Songbirds

"It has a significant effect on endangered birds' abilities to speak if they are unable to understand how to sing properly," said lead author Dr. Ross Crates.

"This may also be contributing to the honeyeater's population loss, as we know that a sexy song raises the likelihood of songbird reproduction. Males who sing strange songs would be rejected by females."

According to the report, males sang rich and nuanced songs in areas where there were still fair numbers of regent honeyeaters. Males sang simplified or "still incorrect" songs where the birds were scarce.

"For example, 18 male regent honeyeaters-roughly 12% of the total population-could only mimic the songs of other bird species," said study co-author Dr. Dejan Stojanovic.

"In a wild animal, this lack of ability to interact with their own kind is unprecedented. We may believe that regent honeyeaters have been extinct to the point where some young males will never find an older male instructor."

Regent Honeyeaters

The Regent Honeyeater has a black head, collar, and upper breast, a lemon yellow back and breast that is scaled black, a white rump, black wings with prominent yellow spots, and a black tail edged yellow. The black eye in males is encircled by yellowish warty bare eyes. Females have a bare yellowish spot under the eye and less black on the throat than males. Young birds are browner and have a paler bill than females. This species is gregarious, and it travels in groups. When it calls, it bobs its ears.

The Regent Honeyeater eats nectar and other plant sugars primarily. Insects and spiders, as well as wild and cultivated fruits, are also potential food sources. It feeds on flowers and foliage but may also descend to the ground to bathe in puddles or ponds and even hawk insects on the wing.

The decline in breeding success is believed to be caused by habitat loss, environmental depletion, and changes in the numbers of nest predator species.

The reduction in the population of regent honeyeaters can also lead to lower nest success. "It's common for royal honeyeaters to breed in groups. Protection in numbers may have helped them protect their nests from predators in the past, but population loss has left them vulnerable."

Honeyeaters in Captivity

Regent honeyeaters born in captivity have entirely different songs than wild birds, according to the report.

This, according to the study team, may be critical in terms of conservation.

"Captive-bred birds' uncommon songs can limit their appeal to wild birds when they are finally released," Dr. Crates said.

"So, using audio recordings, we've devised a new technique for teaching young captive regent honeyeaters to sing the same song as wild birds."

The regent honeyeater's disappearance of song culture is a huge warning sign that it is on the verge of extinction, and we still have a lot to say about how to help them."

The research was presented in the Proceedings of the Royal Society B journal.