For thousands of years, superb lyrebirds have drawn a human audience. Some Indigenous Australians know the bird as beleck-beleck or balangara and many describe it in their Dreamtime stories as the peaceful broker of the bush—the only animal able to communicate with all others. The first colonial settlers found the lyrebird’s song disturbing and unnecessarily hunted males for their tail feathers, which fall out each year and can simply be picked off the forest floor. It took more than a century for the species’ tune to become a cherished anthem for the new nation. In 1931, a male lyrebird from Sherbrooke was the first wild bird broadcast on Australian radio.

Even before recording sound was possible, tales of the lyrebird’s song drew the attention of John Gould, the so-called father of Australian ornithology, as well as the first scientists to formally describe evolution, Alfred Russell Wallace and, of course, Darwin. None of these English naturalists could ultimately agree on why the lyrebird sang or mimicked to such excess. Gould did not accept the theory of natural selection, and Wallace thought a female must choose a trait or behavior because it offered some concrete survival advantage to her offspring, not because she found it aesthetically appealing.

But where Wallace found the male lyrebird “most conspicuous” and “wonderful,” he described the female merely as “unadorned.” Similar perspectives riddle scientific literature. In 1900, Australian-born naturalist Archibald James Campbell wrote, for example, “that only the cock bird whistles and mocks in this magnificent style; the hen makes but feeble attempts.” Darwin, for his part, also hewed to the idea of male superiority. He used lyrebirds to illustrate the central idea of his seminal book, The Descent of Man, and Selection in Relation to Sex, which explores the struggle between males of various species “for possession of the females.”

Pretty much ever since, feminist evolutionists, sometimes called Darwinian feminists, have been working on a more inclusive theory that doesn’t assume males are naturally “superior.” “Social selection theory,” is one way to level the playing field. Popularized by the biologist Mary Jane West-Eberhard in 1978, the theory has come to frame all animal interactions as forces that can shape species, not just those among potential mates or between males. In both sexes, the theory goes, competition and cooperation for food, territory, nesting sites, and other essential resources can contribute to the development of elaborate traits.

It was a duet that initially inspired ornithologists to take another look at the social context of female song. When barred owls (Strix varia) court, the male and female trade a series of alternating gurgles, hoots, caws, and cackles that echo through the treetops like a troop of noisy monkeys. A behavioral ecologist named Karan Odom studied the duet in the late 2000s and began to wonder: If each sex has their own distinct part, could females of other species be singing too?

For more than a century, Western science had defined birdsong as the longer, lyrical, and more elaborate vocalizations that male birds make during the breeding season. But what if that definition was too narrow? Odom joined with other like-minded scientists to look back in history and see if females were ever heard vocalizing in complex ways, even if, at the time, that wasn’t technically considered singing. She spent months pouring through 16 large tomes detailing every described bird species. “I was really surprised how much female song was documented, how much it seems to crop up, again and again,” Odom, an author of the 2014 survey, told me. Across the songbird tree, female voices were clamoring to be heard. Odom and others went on to create the Female Bird Song Project, an online database that aims to systematically catalog female birdsong globally.

Down Under, researchers at the Lyrebird Lab are doing their part. Austin, Dalziell, and Welbergen are the first to place cameras and microphones in and around lyrebird nests. “It’s not all about the males. Rights for females!” Austin half-jokes, pumping an imaginary protest sign as we scramble through wet forest, across streams, over boulders, and under fallen trees on a rainy day in September. We are hunting for female lyrebirds in the Blue Mountains, on the traditional lands of the Dharug and Gundungurra peoples. Suddenly, I hear a high-pitched whip-crack echo through the blue gums, closely followed by a double note: Cooooowheep! Pew! Pew! Austin identifies the sounds as a male and a female whipbird (Psophodes olivaceu). The coordination of their duet was so finely tuned, that if I assumed males were the only singers, I’d have never heard the female’s voice.

Austin keeps her ears peeled but she guides us mainly with her eyes, surveying the forest floor for signs that a lyrebird has been scratching. With young to protect, females rely on silence and subterfuge while they forage for insects or build their nests. Finding them requires dedication and, like today, many unsuccessful outings. It took Austin months to be able to tell the difference between a lyrebird mimicking a goshawk and an actual goshawk—and that distinction is based more on location and behavior than on any noticeable difference between the calls themselves.

“Look,” Austin tells me matter-of-factly when I ask why female song has been disregarded for so long, “a big part of it is that males capture our attention. Males are pretty; they’re loud; they’re obnoxious; they’re just in your face. They’re beautiful, and I get it, but it’s the subtlety of females that interests me. You have to be patient.”

Austin’s years of persistence have paid off. Dressed in camouflage, she’s spent hours crouched outside lyrebird nests, waiting to hear their morning whistles.

Sometimes, she’s noticed, they also sing while foraging. Similar to male lyrebirds, the female’s whistle song is embedded with bouts of mimicry, although their imitations are not as repetitive and they tend to copy more predators. The reasons for the whistling are unclear, but Austin suspects it involves competition for space and resources—and the ongoing need to signal one’s presence to defend those assets. Female lyrebirds are aggressive with one another, destroying each others’ nests and attacking each others’ young. Mothers often build multiple nests throughout their territory, possibly as back-ups, decoys, or territorial markers. Whistling a song every morning could be a safe and easy way to signal: No trespassing.

In one set of experiments, Austin challenged wild female lyrebirds as they left their nests, pulling back a sheet to reveal a stuffed fox, currawong, or rosella. Each of these taxidermied intruders triggers a different response from lyrebirds. Females mostly ignore the innocuous rosella, a colorful parrot that poses no threat to lyrebirds or their offspring. But when a fox is present, females scream in a way that implies multiple voices, like an army of birds facing a threat. Lyrebirds might produce this disorienting alarm to fool a predator into thinking it’s outnumbered or to recruit other animals to drive the threat away.

The idea that mimicry can have multiple origins is supported by hard data. Unlike birdsong, which appears to have arisen in a common ancestor and spread widely through the songbird tree, genetic studies suggest vocal mimicry evolved independently on 237 separate occasions and then disappeared in at least 52 of those cases.

Even within the same species, the use of mimicry is highly variable. For male lyrebirds, learning to vocalize seems to be open-ended, meaning that they continue to accrue and improve their repertoire throughout life. That’s probably what allows them to mimic fire alarms and crying babies when housed at a zoo. But among females, initial studies suggest the best mimics are not necessarily the oldest. Alex Maisey told me that one young lyrebird in Sherbrooke was so vocal, she was known to locals as the “singing female.”

Compared to those in the Blue Mountains, most female lyrebirds in Sherbrooke do not sing consistently. Maisey has spent many a morning huddling near nests in the predawn to confirm what Austin was hearing a state away—but he was met with silence. Perhaps in a smaller forest, where lyrebirds and their predators are more concentrated, singing near the nest is simply too dangerous. When a chick is around, Austin says even females in the Blue Mountains are quieter than normal, most likely for fear of giving away their presence to predators.

In such moments of silence, it’s worth remembering: If a female bird isn’t singing, it doesn’t mean she can’t.

Austin calls this lyrebird Diana. Her ears are now so tuned to females, she can identify individuals by voice alone and can discriminate between regional “accents.” “This is how we discover things,” Austin says, “It’s just humans being interested in the world around them.”

By the look of Diana’s tail, she’s been cooped up in her nest for weeks. In Austin’s time knowing her, she has raised two chicks to maturity, which apparently is “pretty good.” One year, though, a tabby cat—likely from a neighborhood up on the cliffs—stole Diana’s chick a day before it was due to fledge. But lyrebird mothers, perhaps, don’t take losses like that lying down. “There are a couple of female lyrebirds, one here and one in the gully just over, that mimic cats,” Austin says. She’s never heard a male meow, but she’s never searched for it, either.

This story was published with grant support from the Science Journalists Association of Australia.