London, June 13 (ANI): Mother gorillas use "baby talk" gestures to communicating with their infants, according to scientists.
The research team led by Eva Maria Luef from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, studied captive western lowland gorillas, watching and filming the animals as they interacted.
Since the animals have a wide repertoire of communication gestures, the team focused on facial expressions and hand signals used in play.
Luef and her colleague Katja Liebal filmed 120 hours of footage of the gorillas at Leipzig Zoo and Howletts and Port Lympne Wild Animal Parks in the UK.
Analysis of this footage revealed that, when they played with infants, adult females used more tactile gestures than they used with other adults; they would "touch, stroke and lightly slap" the youngsters.
"The infants also received more repetition," the BBC quoted Dr Luef as saying.
She described one particularly motherly gesture, which the researchers call "hand-on".
"This is where mothers put the flat hand of their hand on top of the [infant's] head," Dr Luef explained.
"It means 'stop it'," she said.
The researchers revealed that best of the non-human communicators are the chimpanzees. In the wild, the animals use up to 66 distinct gestures, each with a different meaning.
Gorillas often use this gesture with one another, which apparently means that an animal has "had enough". But in case of an infant, the female would repeat the action several times.
The researchers explain this motherly communication as "non-vocal motherese".
They say that it helps infants to build the repertoire of signals they would later use as adults, in order to communicate with the rest of the gorilla group.
"It also shows that older animals possess a certain awareness of the infants' immature communication skills," Dr Luef said.
Prof Richard Byrne from the University of St Andrews said that he doubted that the research shed any light on the evolution of human "baby talk".
The researcher explained the importance of the way in which adults talk to babies, describing it as a "natural but very smart way of conveying the details of how we construct complex grammar".
But he added that, since gorillas do not acquire language, they have "no need of such an adaptation".
"So I suspect this is not the same at all," he said.
"[But] it is interesting that the adults gesture in a different way to babies than among each other.
"This suggest that adults understand that communicating to infants is going to be tricky, and plan their gesturing accordingly," he added.
The findings were published in the American journal of Primatology. (ANI)