The Avian Sound Archivist
In the cool temperate rainforest of Toolangi, the Superb Lyrebird (Menura novaehollandiae) performs one of the complex vocal displays in the animal kingdom. This ground-dwelling bird, about the size of a pheasant, has a vocal organ called the syrinx, which is the most sophisticated of any songbird. Located at the base of the trachea, the syrinx has a unique structure that allows some birds to produce more than one sound at a time. Lyrebirds leverage this ability to an extreme, with males adding the sounds of 20-25 other species into their courtship songs.
The mimicry is accurate, often fooling the very birds being imitated. Up to 80% of a male lyrebird's song consists of mimicked sounds from his environment. This acoustic collection is not random; it shows vocal fitness. During the breeding season from April to October, the male clears a small mound on the forest floor. On this stage, he performs an elaborate song and dance, fanning his tail feathers—which can be over 70 centimeters long—while cycling through his repertoire of copied sounds.
An Industrial Soundscape
The lyrebird's talent extends beyond the natural world. As human sounds have permeated its forest habitat, the lyrebird has incorporated them into its vocal repertoire. The bird doesn't distinguish between the call of a kookaburra and the sound of a machine; it simply reproduces the complex acoustic information in its territory. This has led to documented imitations of camera shutters, car alarms, and even chainsaws. While some of the most famous recordings of mechanical sounds were made of captive birds, wild lyrebirds readily mimic any sound that is prevalent in their environment.
This mimicry also is used for deception. Researchers have discovered that male lyrebirds can create an acoustic illusion of a mixed-species "mobbing flock"—the panicked sound birds make when a predator is near. A male will deploy this sound when a female attempts to leave his display mound without mating, essentially trying to convince her that it is dangerous to leave. This use of sound makes the lyrebird a unique case study in vocal evolution, demonstrating how an environment's soundscape directly shapes a species' complex behaviors.