Though humans may think they are the masters of deception, some of the world's best con artists appear to be birds. First there is the cuckoo finch that tricks other birds into raising its offspring and now, Africa's fork-tailed drongo that sends out false alarm signals, just so that it can steal food from other birds.
This astonishing ruse that was published in the Science Magazine on May 2nd, was uncovered by a team of scientists led by University of Cape Town's evolutionary biologist Tom Flower, who observed the behavior of 64 fork-tailed drongos for nearly 850 hours in South Africa's Kalahari Desert.
What they found was that the black birds were pretty honest most of the time, getting their meals the 'old fashioned way' - by capturing insects that were zipping by. However, on days when the weather was nippy and insects scarce, or they were in the mood for something a little more substantial, the drongos pulled off an elaborate con.
Animals in the Kalahari Desert are accustomed to listening to each other's alarm calls that warn when predators are approaching. Over the years, the fork-tailed drongo has gained a stellar reputation for its warning calls, which for most part are genuine. However about 25% of the time, they use them as a ruse to obtain a tasty morsel they have caught sight of, inside a fellow bird's beak. Since the bird has no clue it is being deceived, it simply drops everything and scurries away to safety. As soon as the coast is clear, the crafty drongo swoops down, and gets itself a tasty meal.
Though this works most days, sometimes the other birds prove to be a little smarter and refuse to heed the warning. That's when the con gets really interesting. Instead of giving up, the fork-tailed drongos start to emanate alarm calls of one of the numerous other desert species that they have leant to mimic perfectly.
What's amazing is the depth of their repertoire - During the time the birds were observed, the researchers recorded perfect warning call imitations of 50 desert dwellers. Among them were pied babblers, sociable weavers and even mammals like meerkats! The researchers say that while these methods may be deceptive, they are pretty impressive and the only way these birds can get treats like scorpions and geckos - prey they would never been able to catch themselves.
Though fork-tailed drongos are not the only birds to have mastered the art of mimicry, they are the first ones known to be smart enough to use it to their advantage and even change the 'tune' if the first one fails to work.
Also known as Common, Savannah or African drongos, the birds are found in abundance, south of Africa's Sahara Desert. Measuring a mere 25cm long, they have glossy black wings, large heads, bright red eyes and of course, their namesake fork-tails. Though small in size, the insect-eating birds that reside in open forests or bushes are aggressive and not afraid to take on raptors like hawks and eagles especially if their nests are threatened.
Resources: wikipedia.org, sciencemag.org, news.yahoo.com