Male lyrebirds in the throes of sexual union will mimic the sound of a distressed mob of other birds to trick their mate into escaping, new research from Australia has found.
The remarkable discovery was made after analyzing audio and video of magnificent lyre birds, a species known for its quirky dance routines and the ability to mimic the calls of more than 20 other species.
The researchers found that the males could simultaneously reproduce the vocal “mobbing” sounds and the flapping sounds that other bird species make when trying to scare off a predator.
The mimicry of male lyre birds is so precise that it not only misleads the female, but breeding experiments also found that other small birds were tricked into thinking there was a threat nearby.
Captive lyre birds are known to mimic other sounds, including chainsaws and car alarms.
Dr. Anastasia Dalziell, a behavioral ecologist at the University of Wollongong, led the research published in the journal Current Biology.
“Male lyre birds are capable of amazing things and terrible things,” he said.
Dalziell first heard lyrebirds mimic mobbing calls in 2007 and went on to study the ability in detail in two populations: one in Victoria’s Sherbrooke Forest and the other in the Blue Mountains of New South Wales. These locations are 700 km apart.
Along with her colleagues, she was sure the imitation had something to do with mating, but it wasn’t immediately clear why.
But other scientists pointed to similar behavior in other animals. Male topi antelopes use a false alarm call if females wander away from their “display sands”.
The male corn borer moth will mimic the sound of predatory bats long enough to cause the female to freeze, giving the male time to mate.
“Lyrebirds are using the same strategy, but they are doing it in a really exaggerated way, as lyrebirds seem to do,” Dalziell said.
The research found that male lyrebirds only reproduced sound when they had attracted a female to their “display area,” a small space in the forest, cleared for courtship, or when they were copulating.
These two moments, Dalziell says, are crucial to reproductive success, “suggesting that mimicking a stalking flock is crucial sexual behavior for males.”
She said they were even more convinced when footage from her camera showed lyrebirds reacting to mimicry calls and returning to display areas.
When the copycat calls were analyzed in detail, the researchers were able to detect harassment calls that sounded like eastern yellow robins, brown prickly beaks and white-browed scrubs. Occasionally, the researchers detected alarm calls that sounded like two species of possums.
To compare the mock mobbing chorus to a real one, Dalzielle said they had to employ their own deceptive behavior to get local birds to reproduce the calls.
“We threw a rubber snake,” he said.
Male lyrebirds always used their deceptive trick if females tried to escape during mating, Dalziell said.
“The males are doing everything they can to get the female to mate. It’s just one of the many things that men do.
“They have this beautiful dance routine and sing from dawn to dusk, so the female receives all these other beautiful signals. We shouldn’t see lyrebirds as terrible.
“We have a tendency to romance the lyre bird, but they are animals and are capable of amazing things. But they also do things that we don’t like or that we find disturbing and troublesome, like people. “
Lyrebirds will routinely mimic other species, and Dalziell said their repertoire extends beyond 20 different species.
“They only imitate local species. They do it mostly in the breeding season and it’s part of their chorus at dawn, and it’s very, very accurate. “