This suggests, in part, that the meerkats assess the risk of predation before responding, which could further minimize the costs of producing alarm calls through avoiding interrupting foraging when this is not necessary. The predator’s size might also be coded in the bird’s alarm calls. Birds raise false alarm to scare off predators Birds are shameless eavesdroppers, listening and reacting to the calls of other species. Squirrels Mimic Bird Alarms To Foil The Enemy It can take more than just a keen ear to figure out what animals are saying. This large cuckoo tails peccaries as they root around on the forest floor, stirring up insects and other small creatures, as well as fallen fruits. Bird Alarm Calls Size Up Predators, Science magazine [registration required] Bird Alarm Calls Size Up Predators, Science magazine [registration required] We studied the alarm calls of noisy miners, Manorina melanocephala, a species with putatively distinct alarm calls … Birds of prey are the greatest threat to other birds of similar size. Behavior: Allometry of alarm calls: Black-capped chickadees encode information about predator size. A similar result was found in a study of black-casqued hornbills (Ceratogymna atrata), where birds responded more strongly to predator cues than alarm calls when the predator being indicated was an eagle, but not when the predator was a leopard . Spectrographic analysis of more than 5,000 recorded chickadee mobbing alarm calls made under semi-natural conditions showed that the acoustic features of the calls varied with the size of the predator. Chickadees announce an urgent alarm for a small, agile pygmy-owl that’s a major threat to them: [Repeat mobbing sounds] You’d think an eagle would cause a louder alarm, but no. In fact, avian alarm calls are often classified as ‘flee’ (or ‘warning’ or ‘aerial’) alarm calls or ‘mobbing’ alarm calls, suggesting that functionally referential alarm calls in birds, and some mammals, may often classify predators by current behaviour in addition to or instead of the type of predator. Chris Templeton, a biology doctoral student at the University of Washington and lead author of the study, said chickadees produce two very different alarm signals in response to predators. Now, new research indicates that some birds exploit this tendency in order to protect their nests from would-be pillagers. If one bird spots danger and raises an alarm, other species will flee, too. Article ... vary with the size of the predator. (Ground-cuckoos were already known to follow White-lipped Peccaries, which travel in larger herds.)