Animal sounds are ancestral to human speech. Since human language has advanced so far over animal sounds it is unclear to locate the bridgehead on the human shore. Scientists have been studying animal sounds for centuries. As part of the monkey species, vervets are predominant in east Africa. Like other animals, vervets regularly face situations in which efficient communication and representation would help them to survive.
Vervets have complex social relationships with each other.
They live in groups and compete for territory with other groups, they know how to communicate for sources of food, they show discrimination among types of predators and among each other, they respond to dominate and subordinate members of their own groups as well as rival groups, and they show knowledge of who is related to whom. The first clue of communication among vervets came from the observations that biologist Thomas Strusaker made on vervets in Kenya s Amboseli National Park. Vervets utter grunt like calls when interacting with each other. Even to scientists who have spent years listening to vervets, all of the social grunts agreeably sound the same. When the grunts are recorded and displayed on a frequency spectrum, they look the same.