In Australia, drongo is slang for idiot. “That drongo just cut me off!” an Aussie driver might say. The epithet was inspired by a red-eyed black bird native to Australia, New Zealand, and parts of Africa and Asia. But Aussies might want to reconsider their choice of words: According to a new study, the drongo may well be one of the brightest bulbs in the avian world.
Researcher Tom Flower at University of Cape Town, South Africa, found that fork-tailed drongos in the Kuruman River Reserve in South Africa’s Kalahari Desert call out fake warnings to trick other animals, such as meerkats, into abandoning their food so they can steal it.
The duped birds do eventually catch on, but the drongo has come up with a way to keep fooling them – and keep the free meals coming – by mixing up their mimicry.
“Deception is common in nature and other birds have previously been shown to ‘cry wolf,’” Flower said in an email. “What really surprised me is that drongos also employed vocal mimicry to vary their alarms. They changed the type of alarm call they made when a previous call stopped working, thereby maintaining their deception racket.”
Drongos do catch some food themselves, primarily flies they pluck from the air or bugs pecked from the ground. But by raiding the caches of other species, they’re able to greatly diversify their diet. Flower says he’s seen them steal crickets, spiders, scorpions, even geckos – many of which took a lot of work for their original owners to procure.
“All these things are terrestrial and most have to be excavated by other species,” Flower says. Drongos do most of their stealing in the cold winter months, “when flies aren’t moving,” he adds.
Flower and colleagues discovered drongos’ penchant for pilfering while closely monitoring a population of drongos in the Kuruman River Reserve, which lies within the Kalahari Desert in South Africa, not far from the Botswana border. He walked between five and 15 kilometers a day through their sandy habitat, six days a week, for six months every year for five years, observing and recording drongo behavior. Over the course of 847.5 hours, Flower and his fellow researchers counted 688 theft attempts by 64 drongos, they report this week in the journal Science.
“I dread to think how many sand dunes I’ve climbed, but it was worth it to get the data I needed,” Flower says.
Image courtesy Tom Flower