An Endangered Bird Is Forgetting Its Song

Researchers from the Australian National University have found that in areas where there are very small populations of the critically endangered regent honeyeater, the songs of the remaining wild males vary remarkably. Tragically, in some cases, the birds have even adopted the songs of other species.

- Dr Ross Crates, Dr Dejan Stojanovic, Naomi Langmore and Prof Rob Heinsohn

Just as humans learn languages, animals learn behaviours crucial for survival from older individuals of the same species. In this way, important ‘cultures’ such as bird songs are passed from one generation to the next.

But global biodiversity loss means that many animal populations are becoming small and sparsely distributed. This jeopardises the ability of young animals to learn important behaviours.

Nowhere is this more true than in the case of the regent honeyeater (Anthochaera phrygia), a critically endangered, nectar-feeding songbird endemic to south-eastern Australia. A recent paper by Australian National University (ANU) scientists describes how a population crash to fewer than 300 has caused the species’ song culture to break down.

In healthy populations, the song of adult male honeyeaters is complex and long. But where the population is very small, the song is diminished and, in many cases, the birds have adopted the songs of other species. Sadly, this makes the males less attractive to females, which may increase the chance of the regent honeyeater becoming extinct.

Regent honeyeaters once flew in huge flocks between Adelaide and Queensland’s central coast, tracking eucalyptus blossoms. As recently as the 1950s, the species was a common sight in suburban Melbourne and Sydney, but it is now extremely rare in these cities.

Extensive post-war land clearing has destroyed regent honeyeater habitat and caused the population to plummet. Most breeding activity is now restricted to the Blue Mountains and Northern Tablelands in New South Wales.