The forest's sound editor
In the wet and dense forests of southeastern Australia lives one of nature's most accomplished vocal artists. The superb lyrebird, Menura novaehollandiae, is a ground-dwelling bird famous for its ability to accurately reproduce almost any sound it hears. This includes the calls of other birds, and the sounds of chainsaws, camera shutters, car alarms, and even the barking of dogs.
The male superb lyrebird's song is a complex song. Up to 80% of his vocalizations are imitations of other species. He samples sounds from his environment and weaves them into a long, continuous song, primarily for courtship. During the breeding season from June to August, a male may sing for up to four hours a day. The mimicry is so precise that even the species being imitated can be fooled. This skill is not innate; young lyrebirds learn the sounds, creating regional dialects based on the acoustic environment they grew up in. A male's repertoire can include the calls of more than 20 other bird species, such as the laughing kookaburra and the eastern whipbird.
The courtship display is a display. The male clears a small patch of forest floor to create a "mound," or stage. Here, he performs his song and dance, fanning his 75-centimeter-long tail feathers over his head. The performance is choreographed, with specific dance moves precisely synchronized to particular songs.
A uniquely complex voice box
The lyrebird's vocal ability is possible because of its syrinx, the avian vocal organ. Located at the base of the trachea where it splits into the bronchi, the syrinx produces sound through the vibration of membranes as air flows past them. While all songbirds (passerines) have a complex syrinx, the lyrebird's is exceptional. It possesses fewer syringeal muscles than most songbirds—three pairs instead of the typical four—but they are arranged to provide an high level of independent control.
This unique anatomy allows the lyrebird to produce two different sounds simultaneously. It can sing with two independent voices, creating layered harmonies and accurately replicating the complex sounds of an entire flock of birds. Research shows males can mimic the sound of a "mobbing flock"—a chaotic mix of alarm calls and wingbeats from multiple species harassing a predator. Males sometimes use this specific mimicry when a female tries to leave his display mound, possibly to deceive her into thinking a predator is nearby, encouraging her to stay. The acoustic fidelity is so high that recordings of a lyrebird's mobbing flock imitation will attract other small birds, just as a real flock would.