Call of the wild comes with its advantages
May 07 2014
Alarm calls are specific vocalisations produced by animals when facing impending danger. They can encode rich information about the type and intensity of threat. The best way to avoid being eaten by a predator is simply to stay out of its way. But sometimes, when they happen to come face to face with a predator, they let out alarm calls in the presence of the predator, allowing other animals of the to flee.
But why should an individual risk its own survival to produce costly warnings of a predator’s presence? While some experts agree that these calls are intended as a warning for other individuals of the same species, others have offered an alternative interpretation —that some alarm calls may be intended for the threatening predator itself. For example, the prey may be able to deter pursuit by informing a predator that it has been detected, and thereby persuading the predator to look for an easier catch elsewhere. Similarly, the prey may be able to deter pursuit by convincing a predator that they are particularly skilled at escape, or particularly dangerous if attacked.
Alarm call behaviour is not easily explained as a warning to other deer. If the calls were intended for the others in the herd, why would the deer continue calling long after the entire herd has joined in? And why would the deer employ such a loud alarm call, which may attract further attention from predators, when a much softer call would seemingly be sufficient to alert other members of the flock? Which is why many experts theorise that alarm calls are actually directed at the predator, rather than other potential prey. By raising the alarm loudly, the deer informs the crouching predator hiding behind a tree — say, a tiger or leopard — that it has been seen, and that any attack will likely be unsuccessful.
This explanation raises an additional question, however. If alarm calls actually deter a predator’s attack, why would a deer not gain from calling indiscriminately, even before sighting a predator, on the offchance that one is present?
The explanation from experts for this is: “A deer who would cheat by alarming before it saw a predator would expose itself to predators it might not have noticed. That risk helps ensure that if a deer declares it has seen a predator, it has indeed seen one.”
The jungle has its own way of functioning, its language is different, although it is vocal, we still have to explore many of its functionings. Which is why experts continue to be puzzled about the alarm call behaviour of animals.
(The writer is a conservation biologist at Tiger Watch, Ranthambore)