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

UN: 1 Million Somalis at Risk of Hunger

Group warns region is in dire need of humanitarian aid, with at least 200,000 children under age of five acutely malnourished as drought hits southern, central part of nation More

Human Rights Groups Allege Supression of Freedoms in Thailand

Thailand’s military, police have suppressed release of independent report assessing human rights in kingdom during first 100 days of latest coup More

Jennifer Lawrence Contacts FBI After Nude Photos Hacked

'Silver Linings Playbook' actress' photos were posted on image-sharing forum 4chan; Federal Bureau of Investigations is looking into matter 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.
Ukraine Schools Resume Classes, Donate to Government Forcesi
X
September 02, 2014 12:58 PM
A new school year has started in Ukraine but thousands of children in the war-torn east are unable to attend because of ongoing clashes with pro-Russia rebels. In Ukraine's capital, patriotic education has become the norm along with donations to support injured security forces fighting to take back rebel-held areas. VOA's Daniel Schearf reports from Kyiv.
Video

Video Ukraine Schools Resume Classes, Donate to Government Forces

A new school year has started in Ukraine but thousands of children in the war-torn east are unable to attend because of ongoing clashes with pro-Russia rebels. In Ukraine's capital, patriotic education has become the norm along with donations to support injured security forces fighting to take back rebel-held areas. VOA's Daniel Schearf reports from Kyiv.
Video

Video US Detainees Want Negotiators for Freedom in North Korea

The three U.S. detainees held in North Korea were permitted to speak with foreign media Monday. The government of Kim Jong Un restricted the topics of the questions, and the interviews in Pyongyang were limited to five minutes. Each of the men asked Washington to send a representative to Pyongyang to secure his release. VOA’s Carolyn Presutti has our story.
Video

Video Internet, Technology Offer New Tools for Journalists

The Internet and rapidly evolving technology is quickly changing how people receive news and how journalists deliver it. There are now more ways to tell a story than ever before. One school in Los Angeles is teaching the next generation of journalists with the help of a state-of-the-art newsroom. Elizabeth Lee has this report.
Video

Video Turkmen From Amerli Describe Survival of IS Siege

Over the past few weeks, hundreds of Shi'ite Turkmen have fled the town of Amerli seeking refuge in the northern city of Kirkuk. Despite recent military gains after U.S. airstrikes that were coordinated with Iraqi and Kurdish forces, the situation remains dire for Amerli’s residents. Sebastian Meyer went to Kirkuk for VOA to speak to those who managed to escape.
Video

Video West Africa Ebola Vaccine Trials Possible by Early 2015

A U.S. health agency is speeding up clinical trials of a possible vaccine against the deadly Ebola virus that so far has killed more than 1,500 people in West Africa. If successful, the next step would be a larger trial in countries where the outbreak is occurring. VOA's Carol Pearson has more.
Video

Video Survivors Commemorate 70th Anniversary of Nazi Liquidation of Jewish Ghetto

When the German Nazi army occupied the Polish city of Lodz in 1939, it marked the beginning of a long nightmare for the Jewish community that once made up one third of the population. Roughly 200,000 people were forced into the Lodz Ghetto. Less than 7,000 survived. As VOA’s Kane Farabaugh reports, some survivors gathered at the Union League Club in Chicago on the 70th anniversary of the liquidation of the Lodz Ghetto to remember those who suffered at the hands of the Nazi regime.
Video

Video Cost to Raise Child in US Continues to Rise

The cost of raising a child in the United States continues to rise. In its latest annual report, the U.S. Department of Agriculture says middle income families with a child born in 2013 can expect to spend more than $240,000 before that child turns 18. And sending that child to college more than doubles that amount. VOA’s Deborah Block visited with a couple with one child in Alexandria, Virginia, to learn if the report reflects their lifestyle.
Video

Video Chaotic Afghan Vote Recount Threatens Nation’s Future

Afghanistan’s troubled presidential election continues to be rocked by turmoil as an audit of the ballots drags on. The U.N. says the recount will not be completed before September 10. Observers say repeated disputes and delays are threatening the orderly transfer of power and could have dangerous consequences. VOA correspondent Meredith Buel reports.

AppleAndroid