Eavesdropping Iguanas Use Mockingbird Calls To Survive
by Jason G. Goldman
Predator-prey interactions are often viewed as evolutionary arms races; while predators improve their hunting behaviors and their ability to sneak up on their prey, the prey improve upon their abilities to detect and escape from their predators.
The problem, of course, is that there is a trade-off between maintaining vigilance – the attention necessary to be consistently aware of others in the environment takes quite a bit of physical and mental energy – and doing all the other things that an animal must do, such as finding its own food. As a result of this trade-off, many social species, especially mammalian and avian species, have developed alarm calls. Alarm calls are specific vocalizations that signal the presence of a danger in the environment to nearby conspecifics, and sometimes contain additional information about the type of threat or predator.
Subsequent to the introduction of predatory birds, howler monkeys on Barro Colorado Island near Panama rapidly developed an alarm call specific for those birds that indicated the presence of an avian predator: something like “danger from above!” They did not merely adapt an already existing alarm call to the new predator, they developed an entirely new one…
(read more: Scientific American)
Images: Galapagos Marine Iguana via Flickr/Max xx, Galapagos Mockingbird via Smugmug/Jerry Fiddler.