- Male superb lyrebirds can mimic the sounds of an entire multispecies flock during courtship and mating.
- The study suggests that males use the flock mimicry to deceive females into believing there is a predator nearby and thus preventing them from breaking off courtship or leaving before copulation, thereby increasing their chances of successfully mating.
- Researchers say the elaboration of this mimetic song could be driven by male deception and sexual conflict, rather than females’ preferences for male extravagance and male-male competition, which are the most common explanations for sexual selection.
The superb lyrebird has garnered worldwide recognition as nature’s greatest voice impersonator. Researchers have found that besides imitating other species’ songs and artificial sounds from the environment, it is capable of mimicking the sounds of an entire multispecies flock. This vocal mimicry is used by males during mating sessions and is believed to increase their reproductive success.
Masters of imitation
The superb lyrebird (Menura novaehollandiae) is a large ground-dwelling songbird endemic to southeastern Australia. It’s best-known for its extraordinary ability to imitate complex artificial sounds from the environment, even chainsaws, camera shutters, squeaking trees, and car alarms.
A study published Feb. 25 in Current Biology adds one more astonishing feat to its repertoire: male lyrebirds can mimic the panicked alarm calls and wingbeat noises of many bird species all at once. This illusion of creating a complex ecological scene has never before been seen in birds.
“In the past, biologists have specified that mimicry involves three protagonists: a mimic, a signal receiver, and a model. But here we have an example of one individual — a male lyrebird — mimicking an entire ecological scene comprising multiple individuals and multiple species calling simultaneously,” Anastasia Dalziell, a behavioral ecologist at the Cornell Lab of Ornithology and lead author of the paper, says in a statement.
This audio clip is a segment of a real mixed-species mobbing flock experimentally induced in Sherbrooke Forest. Audio courtesy of Dalziell et al.
This audio clip is an example of a male lyrebird imitating a mobbing flock during copulation. Audio courtesy of Dalziell et al.
Lyrebirds perform this acoustic extravaganza during courtship and mating sessions. But how are males benefiting from this vocal mimicry? Dalziell and her team used audio-visual footage from the wild to investigate this.
A sensory trap
According to Darwin’s sexual selection theory, the evolution of elaborate behavioral displays and morphological traits in animals increases their chances of attracting the opposite sex, leading to reproductive success. We see this across the animal kingdom, from birds-of-paradise with their intricate mating dances and bright, colorful plumage, to male deer with huge antlers.
Australia’s superb lyrebirds seem to have the upper hand at advertising their fitness: they can sing, dance, and even do impersonations! During mating season, males prepare their stage by clearing a patch of forest floor and building display mounds where they stand and follow a choreographed dance, fanning out their long tails and singing complex songs — songs that incorporate lyrebird-specific calls with others borrowed from other species and the environment.
Even after all the males’ efforts to lure their potential partners, females may sometimes lose interest and leave before mating.
Male lyrebirds may have found a solution to females’ premature departures by adding the sounds of a mobbing flock to their courtship and mating ritual.
Usually, when birds see a potential predator, as a defensive strategy they produce loud calls and attract birds from other species to do the same in an attempt to drive away the threat. The authors suspect that male superb lyrebirds use the flock mimicry to deceive females into believing there is a predator nearby.
“It’s a bit like saying, ‘baby, it’s dangerous out there. Stay here with me,'” Dalziell explains.
“Astonishingly, males only mimic a mobbing flock in two contexts: when a potential mate tries to leave a displaying male without copulating, or during copulation itself. These two moments are key to male reproductive success, suggesting that mimicking a mobbing flock is a crucial sexual behavior for males.”
So by creating this false alarm, males prevent females from breaking off courtship or leaving during mating, and hence increasing their chances of successfully mating.
Video of a male superb lyrebird mimicking a mobbing flock after a female leaves the male’s display mound without copulating. Video courtesy of Dalziell et al.
Superb lyrebirds seem to be going to a great extent to create this sensory illusion, and Dalziell points out that males also appear to be covering the female’s head with their wings while mating.
“Are males ‘blindfolding’ females to prevent females from detecting the male’s deception?” Dalziell asks.
She says the elaboration of this mimetic song could be driven by male deception and sexual conflict, rather than females’ preferences for male extravagance and male-male competition, which are the most common explanations for sexual selection.
The study brings us one step closer to unraveling the secrets of the elusive superb lyrebird, and researchers say they are determined to continue exploring the drivers behind the remarkable acoustic illusion.
Banner image by Alex Maisey.
Related listening: Anastasia Dalziell discussed the bioacoustics of the superb lyrebird on Mongabay’s podcast, listen here:
Dalziell, A. H., & Magrath, R. D. (2012). Fooling the experts: Accurate vocal mimicry in the song of the superb lyrebird, Menura novaehollandiae. Animal Behaviour, 83(6), 1401-1410. doi:10.1016/j.anbehav.2012.03.009
Dalziell, A. H., Peters, R. A., Cockburn, A., Dorland, A. D., Maisey, A. C., & Magrath, R. D. (2013). Dance choreography is coordinated with song repertoire in a complex avian display. Current Biology, 23(12), 1132-1135. doi:10.1016/j.cub.2013.05.018
Dalziell, A. H., & Welbergen, J. A. (2016). Elaborate mimetic vocal displays by female superb lyrebirds. Frontiers in Ecology and Evolution, 4, 34. doi:10.3389/fevo.2016.00034
Dalziell, A. H., Maisey, A. C., Magrath, R. D. & Welbergen, J. A. (2021). Male lyrebirds create an acoustic illusion of a mobbing flock during courtship and copulation. Current Biology. doi:10.1016/j.cub.2021.02.003