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Cape Town - It’s called the Fork-tailed Drongo, but a more accurate name for this feisty little African bird might be the Fork-tongued Drongo because of its ability to lie, cheat and deceive.
Now, its remarkable “immoral” behaviour has been observed and documented by researchers deep in the red dunes of the Kalahari where they found this bird regularly fools even the reputedly clever meerkat.
The drongo has a unique ability to mimic the meerkats’ alarm call, sending these little mammals scampering to the safety of their burrows and abandoning their food so that the bird can swoop down enjoy a free meal at their expense. And it can do this repeatedly until the one false alarm call stops working, when it then mimics a different alarm call to maintain the deception and access to stolen food.
And it’s not only the meerkat that is taken in by the drongo’s ability to make realistic false alarm calls: Dr Tom Flower, a post-doctoral student at UCT’s Percy FitzPatrick Institute of African Ornithology, and colleagues have discovered the bird is able to vocalise false warning calls that also deceive at least 25 other species, notably Pied Babblers, Yellow-billed Hornbills, Lilac-breasted Rollers and Sociable Weavers – and on one notable occasion, even his then 18-month-old daughter Audrey.
“So far the only (wild) mammal is the meerkat, but that might just be because we can’t get close enough to other species like the bat-eared fox – birds are much more trusting,” Flower explained in an interview in his UCT office this week.
Their research appears in the latest issue of the prestigious journal Science, and the fascinating study has been quickly picked up by journalists around the globe.
The Kalahari is a long way from the UK where Flower was an avid natural historian as a child before going on to do a degree in biology at Bristol University. He then applied to join the world-famous Meerkat Project that has been running since 1993 at the Kuruman River Reserve outside Van Zylsrus near the Botswana border – the highly successful TV series Meerkat Manor was also filmed here – where he did his research. He worked there for a year before being appointed project manager for the next three years (2005 to 2007) during which time he also did a Master’s degree at the University of Pretoria on meerkats.
While he was busy with that work, he noticed “all these lovely things happening with the drongos”, he says.
“And I did my PhD through Cambridge University on that, to really prove scientifically the natural history observation. It’s one thing to see something happening, it’s another to do the experimentation and to provide the hard evidence.”
For his research, Flower walked between five and 15km a day, six days a week, for six months each year since 2008, observing and recording drongo behaviour. He calculates that he’s probably spent a total of six years during the past decade in the field in the Kalahari, where temperatures ranged from –11°C on cold winter mornings to 42°C in the height of summer.
“I dread to think how many sand dunes I’ve climbed, but it was worth it to get the data I needed.”
While meerkats were a route into the project – the first person to record drongos mimicking meerkat alarms had been UCT zoology professor Justin O’Riain some years earlier, he points out – it was actually another very long-term study of well-studied species at the nature reserve, the Pied Babbler, that really provided most of the evidence during interactions with the drongos, he explains.
“They’re a much more prevalent host – a lovely bird, just like the meerkat in their socialisation, and much smarter than the meerkat! They were the guys I did all my experimentation on and that part of the study was run by my co-author, Amanda Ridley. But they tended to get washed aside in favour of the ‘sexy’ meerkats!”
Flower is not surprised by the huge media attention their paper has attracted, but as an evolutionary biologist he does not agree with the seemingly obvious conclusion drawn by many journalists: that drongos are showing intelligence on a human scale and outwitting the supposedly smart and generally lovable meerkats.
“It seems very clever, doesn’t it? You could say, the drongo has thought about what’s going to work on those animals and has then chosen the exact alarm call that is best for that occasion, because it knows that’s what is going to work best next time. And that’s precisely what a human might do – but doesn’t mean it’s what a drongo does.”
Seeing an animal doing something that only humans can usually do, doesn’t mean that the animal has human-like abilities, Flower continues.
“That’s been roundly disproved – if you see an animal do something like a human, more than likely it’s achieved by a completely different mechanism. And for me that makes it a whole lot more interesting: something like a drongo could perfectly well accomplish its behaviour using a range of alternative mechanisms, like trial-and-error learning, although it might have something a bit more complex than that, like cause-and-effect.”
He now spends less time in the Kalahari than previously, just one week every couple of months. “Principally because I’ve now got more data than I know what to do with, and I need to write it up – more and more questions spill out – but also I’ve got two kids now as well!”
His young daughters, aged one and three, have accompanied him and his wife Martha, a fellow zoologist also doing a post-doc at UCT, to the Kalahari and on one occasion provided additional evidence for his work.
“There was a drongo that would come to our doorstep, and I was getting Audrey to feed it some worms,” he recalls.
“And sure enough, the drongo saw her walk to the edge of the stoep with the worms in her hand and it shrieked at her, diving down at her and making a false alarm. And she dropped the worms and ran to her dad screaming while the drongo swooped down and took the worms. It was hilarious!” - Cape Argus