From Science. Flower, Gribble & Ridley. 2014. Deception by Flexible Alarm Mimicry in an African Bird.
“Forked-tailed drongos are a particularly intelligent type of bird found in Africa. Drongos associate with many other bird and mammal species, which can learn to respond to drongo warning calls. Drongos are also exceptional mimics of the other species’ alarm calls. Though the increased vigilance across these multi-species associations is a benefit to all, drongos sometimes use these calls as ploys to scare associated species away from food, which the drongos then steal. However, without some approach to maintain the effectiveness of this deception, the drongos’ ploy would soon be detected. Flower et al. now show that drongos are able to fool their target species longer by flexibly varying the type of call they give.”