African Bird Uses Sound Effects To Steal Food
A forked tailed drongo bird of Africa imitates multiple species' warning calls to scare off other animals and steals their food, according to a new study.
Birds often use their own danger alert to trick their fellow bird but researchers were unsure why animals never wise up to the false-warning scheme.
Researchers followed 64 drongos over the course of 847 hours and found that the bird can mock up to 51 other bird and mammal alert noises including the mongoose and jackal.
Biologists added that since the bird can imitate so many species' warnings, animals do not get used to bird's own false alerts.
When the bird's alert cry is no longer taken seriously, the drongo switches to another species in its repertory, said author Tom Flower, a biologist at the University of Cape Town in South Africa.
"They're rather demonic little black birds with red eyes, a hooked beak and a forked tail," added Flower, according to Reuters.
"They're also highly aggressive and are renowned for attacking eagles and hawks, for which they apparently have no fear."
These birds are common in southern Africa and usually get meals the honest way. However in rough times, like in cold mornings when few insects are flitting around, these drongos turn to a life of crime.
"All the animals in the Kalahari eavesdrop on each other's alarm calls, which provide invaluable information about potential predators. It's a bit of an information superhighway where all the animals speak each other's language," Flower said.
"Because drongos give reliable predator information some of the time, it maintains host responsiveness (of other animals) since they can never know if the drongo is lying or telling the truth," added Amanda Ridley, an evolutionary biologist at the University of Western Australia, another of the researchers.
The study has been published in the journal Science.