News / Science & Technology

Liar! Liar! African Bird Uses Elaborate Ruse to Steal Food

FILE - A drongo sits on a pole in a paddy field on the outskirts of Gauhati, India.
FILE - A drongo sits on a pole in a paddy field on the outskirts of Gauhati, India.
Reuters
If you believe honesty is the best policy, you would have a hard time convincing the forked-tailed drongo. This tricky African bird is the pathological liar of the animal kingdom.
 
Scientists described on Thursday how this medium-sized bird brazenly deceives other animals by mimicking alarm calls made by numerous bird species - and even meerkats - to warn of an approaching predator in a ruse to frighten them off and steal food they leave behind.
 
The researchers tracked 64 forked-tailed drongos over a span of nearly 850 hours in the Kalahari Desert in South Africa close to the Botswana border to unravel this unique behavior.
 
"They're rather demonic little black birds with red eyes, a hooked beak and a forked tail," said evolutionary biologist Tom Flower of the University of Cape Town in South Africa.
 
"They're also highly aggressive and are renowned for attacking eagles and hawks, for which they apparently have no fear," added Flower, whose study appears in the journal Science.
 
These birds, common in southern Africa, usually get meals the honest way, such as capturing insects in mid-air using their superb aerial skills.
 
But at other times, like on cold mornings when few insects are flitting around, the drongos turn to a life of crime.

False alarm
 
The drongos are able to mimic the sounds made by many different species that inhabit its desert environment, including birds such as pied babblers, glossy starlings, sociable weavers and pale chanting goshawks as well as mammals like meerkats.
 
The drongos carry out an elaborate con. They give their own genuine alarm call when they spot a predator approaching - essentially behaving as sentries - and other animals come to trust that this call signals real danger.
 
But they sometimes give this alarm call when no danger exists to fool other animals into fleeing and abandoning their food.
 
Then the drongos swoop down for a free lunch.
 
"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 scientists noticed that sometimes the other animals "get wise" to the con and ignore repeated false alarm calls. But then the wily drongos simply grab another tool from their toolbox of trickery - they mimic the alarm calls made by other animals, once again conning them into fleeing and leaving their chow behind.
 
Flower observed drongos mimicking more than 50 calls.
 
When stealing food from other animals, drongos are able to eat larger prey than they normally would be able to capture on their own like scorpions, beetle larvae and even geckos.
 
"Crime pays," Flower said, noting that the stolen stuff accounted for about a quarter of the food eaten by the drongos.
 
"One could argue that the strategy of the drongo to steal food from others seems very dishonorable in human standards. But, yes, if it has found such a crafty way to catch food, which is usually much larger than the food items it catches itself, then we cannot help but admire this clever little bird's adaptiveness," Ridley added.
 
The researchers classify the drongo as "a kleptoparasite."
 
There are many examples of mimicry and deception in the animal kingdom. About 20 percent of song birds mimic the calls of other birds, Flower noted.
 
"However, drongos are the only ones to flexibly produce the specific signals that best deceive their different hosts and to maintain their deception racket by changing signal when the previous signal failed," Flower added

You May Like

Multimedia US Defense Secretary: Iraqi Forces Lack 'Will to Fight'

Ash Carter criticizes Iraq's reaction to Islamic State; National Security Advisor Susan Rice echoed Carter's concerns in an interview on CBS More

Boko Haram Surrounds Havens With Land Mines

Chad and Cameroon say huge numbers of land mines planted by Boko Haram fighters along Cameroon's border with Nigeria are a danger to people, livestock and soldiers More

Women Peace Activists Cross Korean DMZ

Governments of Koreas give international delegation of women peace activists permission to pass through heavily fortified border, but some critics say symbolic crossing only benefits Pyongyang More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Turkey's Main Opposition Party Hopes for Election Breakthroughi
X
May 22, 2015 10:23 AM
Turkey’s main opposition Republican People’s Party has sought an image change ahead of the June 7 general election. The move comes after suffering successive defeats at the hands of the Islamist-rooted AK Party, which has portrayed it as hostile to religion. Dorian Jones reports from the western city of Izmir.
Video

Video Turkey's Main Opposition Party Hopes for Election Breakthrough

Turkey’s main opposition Republican People’s Party has sought an image change ahead of the June 7 general election. The move comes after suffering successive defeats at the hands of the Islamist-rooted AK Party, which has portrayed it as hostile to religion. Dorian Jones reports from the western city of Izmir.
Video

Video Europe Follows US Lead in Tackling ‘Conflict Minerals’

Metals mined from conflict zones in places like the Democratic Republic of Congo are often sold by warlords to buy weapons. This week European lawmakers voted to force manufacturers to prove that their supply chains are not inadvertently fueling conflicts and human rights abuses. Henry Ridgwell reports from London.
Video

Video Class Tackles Questions of Race, Discrimination

Unrest in some U.S. cities is more than just a trending news item at Ladue Middle School in St. Louis, Missouri. As VOA’s Kane Farabaugh reports, it’s a focus of a multicultural studies class engaging students in wide-ranging discussions about racial tensions and police aggression.
Video

Video Mind-Controlled Prosthetics Are Getting Closer

Scientists and engineers are making substantial advances towards the ultimate goal in prosthetics – creation of limbs that can be controlled by the wearer’s mind. Thanks to sophisticated sensors capable of picking up the brain’s signals, an amputee in Iceland is literally bringing us one step closer to that goal. VOA’s George Putic reports.
Video

Video Afghan Economy Sinks As Foreign Troops Depart

As international troops prepare to leave Afghanistan, and many foreign aid groups follow, Afghans are grappling with how the exodus will affect the country's fragile economy. Ayesha Tanzeem reports from the Afghan capital, Kabul.
Video

Video Poverty, Ignorance Force Underage Girls Into Marriage

The recent marriage of a 17-year old Chechen girl to a local police chief who was 30 years older and already had a wife caused an outcry in Russia and beyond. The bride was reportedly forced to marry and her parents were intimidated into giving their consent. The union spotlighted yet again the plight of many underage girls in developing countries. Zlatica Hoke reports poverty, ignorance and fear are behind the practice, especially in Asia and Africa.
Video

Video South Korea Marks Gwangju Uprising Anniversary

South Korea this week marked the 35th anniversary of a protest that turned deadly. The Gwangju Uprising is credited with starting the country’s democratic revolution after it was violently quelled by South Korea’s former military rulers. But as Jason Strother reports, some observers worry that democracy has recently been eroded.
Video

Video California’s Water System Not Created To Handle Current Drought

The drought in California is moving into its fourth year. While the state's governor is mandating a reduction in urban water use, most of the water used in California is for agriculture. But both city dwellers and farmers are feeling the impact of the drought. Some experts say the state’s water system was not created to handle long periods of drought. Elizabeth Lee reports from Ventura County, an agricultural region just northwest of Los Angeles.
Video

Video How to Clone a Mammoth: The Science of De-Extinction

An international team of scientists has sequenced the complete genome of the woolly mammoth. Led by the Swedish Museum of Natural History in Stockholm, the work opens the door to recreate the huge herbivore, which last roamed the Earth 4,000 years ago. VOA’s Rosanne Skirble considers the science of de-extinction and its place on the planet
Video

Video Blind Boy Defines His Life with Music

Cole Moran was born blind. He also has cognitive delays and other birth defects. He has to learn everything by ear. Nevertheless, the 12-year-old has had an insatiable love for music since he was born. VOA’s June Soh introduces us to the young phenomenal harmonica player.

VOA Blogs