You are going to read an article about a bird that steals food by imitating the calls of other animals. Some words are missing from the text.
Choose the most appropriate answer from the options (A-D) for each gap in the text.



Drongos in the Kalahari Desert mimic the alarm calls of other species in (1) ______ to steal food, scientists have found.
The birds "play tricks" (2) ______ meerkats in particular, following the little mammals around until they (3) ______ catch a meal. The drongos then make fake alarm calls and cause the meerkats (4) ______ for cover, allowing the drongos to swoop in.
The scientists (5) ______ their work studying meerkats and noticed their reaction to the drongos' alarm calls. When a predator was in the area, the birds made an alarm call and the meerkats immediately dashed for cover. But when the drongos saw a meerkat with a large food item such as a gecko or a scorpion, they made a false alarm call (6) ______ sounded the same as the calls they made at predators, (7) ______ there were no predators around.
The researchers then turned their attention to the drongos. To avoid (8) ______ ignored, the birds appear to deliberately change the type of call they make - to alter the species they mimic – when meerkats stop (9) ______ to their alarm calls.
Although (10) ______ species they impersonated were other birds, drongos even managed a meerkat alarm call. The birds may have learned by trial and error that meerkats are (11) ______ to find their own alarm call "particularly convincing". This is one of the first studies to show that vocal mimickry can have a function.