The Lyrebird Learned to Imitate a Chainsaw.

Menura novaehollandiae, the superb lyrebird of southeastern Australia, is the most accomplished vocal mimic in the animal kingdom. This is not a casual claim. The lyrebird can reproduce the calls of over 20 other bird species with accuracy sufficient to fool the birds being imitated. It can replicate the sounds of camera shutters, car alarms, crying babies, and construction equipment. One individual recorded in the 1990s in the Sherbrooke Forest near Melbourne had incorporated the sound of a chainsaw into its display repertoire, a sound it could only have learned from the logging operations that were reducing the forest around it.

The irony of that particular imitation is not subtle.

The lyrebird’s vocal apparatus, the syrinx, is the most complex of any bird, with muscles capable of producing sounds across a frequency range and with a precision that no other bird matches. The mimicry is not random. Male lyrebirds incorporate imitated sounds into their courtship displays, building elaborate song sequences that mix their own species-specific calls with imitations of other species and environmental sounds. The complexity and accuracy of the display appears to influence female mate choice, with males that produce more varied and accurate imitations being preferred.

What I find genuinely striking about this is the speed of cultural transmission. A sound that did not exist in the lyrebird’s environment 50 years ago, the chainsaw, has been incorporated into the repertoire of individuals who learned it from other individuals who learned it from the original exposure. The sound spreads through the population the way a word spreads through a language, carried by learning rather than genetics.

The Display

The male lyrebird’s tail is the other half of the story. The two outer tail feathers are shaped like the frame of a lyre, the ancient stringed instrument, with filamentous inner feathers that fan out between them during display. The full tail display, combined with the vocal performance, is one of the most elaborate courtship behaviors in the bird world.

The display ground is a mound of earth that the male constructs and maintains, clearing the surrounding area of debris and returning to the same mound across multiple breeding seasons. During display, the male spreads his tail forward over his body, creating a shimmering curtain of feathers that obscures his body while he sings. The combination of visual spectacle and acoustic complexity is designed, in the evolutionary sense, to be overwhelming.

Females visit multiple display grounds before selecting a mate, and they raise their single chick entirely alone. The male contributes nothing to incubation or chick-rearing, investing all his energy in the display that attracts females in the first place.

The Forest and the Future

Superb lyrebirds are not currently threatened, but their habitat in the wet sclerophyll forests of southeastern Australia has been significantly reduced by logging, agriculture, and the increasingly severe bushfires that have burned through large areas of their range in recent decades. The 2019 to 2020 Australian bushfire season burned approximately 5 million hectares of lyrebird habitat, and population surveys afterward documented significant local declines.

The lyrebird’s dependence on dense, mature forest with deep leaf litter for foraging makes it sensitive to habitat degradation in ways that more generalist species are not. It needs old forest. Old forest is what Australia has been losing fastest.

The bird that learned to imitate the sound of the machine destroying its home is still singing that imitation in the forests that remain. It does not know what the sound means. It knows only that the sound is part of the world it lives in, and so it sings it, perfectly, into the trees.