Ravens have been observed using their beaks and body language to direct another raven's attention, marking the first time such complex gesturing has been documented beyond humans and their primate cousins.
Wild ravens in the Austrian alps have been observed using their beaks and body language to direct another raven's attention to a specific object, marking the first time such complex gesturing has been documented in an animal outside of humans and their primate cousins.
By repeatedly demonstrating a kind of "look at that" gesture thought to be at the foundation of human language -- behavior seen in human infants beginning at about the age of 1 -- the birds may even be smarter than some nonhuman primates, according to a study published today in the journal Nature Communications.
"Gesture studies have too long focused on communicative skills of primates only," said Simone Pika, of the Max Planck Institute for Ornithology, in a story about the research. "The mystery of the origins of human language, however, can only be solved if we look at the bigger picture and also consider the complexity of the communication systems of other animal groups."
"Recently, the idea of the bird family Corvidae representing a mirror group to the primates in respect to cognitive capacities has gained momentum," wrote study co-author Thomas Bugnyar, at his "Raven Politics" project website. "Understanding the social life of corvids may thus be critical in our attempt to understand primate cognition, since comparison between these groups may offer the unique opportunity to identify which cognitive abilities are common to social living. …"
Humans begin gesturing long before they can hold a conversation. Think of how babies will point to food or toys as a way to direct a parent's attention. These "triadic interactions" -- involving two people and one object -- are more complex than one might assume, involving eye contact and other social behavior. The focus isn't on using the object but on drawing the other person's attention to it.
"These gestures thus mark a pivotal change in the infant's communicative competence and have been viewed as the foundation to engage in symbolically mediated conversations," the two scientists wrote.
"In stark contrast, observations of comparable gestures in our closest living relatives, the great apes, are relatively rare and mainly concern captive and/or human-raised individuals."
About the only similar gesturing documented in the wild involves chimps indicating where they want a partner to groom them, they wrote.
In the current study, Pika and Bugnyar observed and filmed 38 social interactions among seven raven pairs over the course of three seasons in 2008, 2009 and 2010.
The birds would pick up bits of moss or twigs and then show them or offer them to the other bird, usually either a mate or a potential mate. The other bird might respond by turning to the first bird and orienting to the object. There would be eye contact, and long pauses.
The scientists say the birds were clearly presenting the objects so that the other bird would notice them.
"Twenty-five instances consisted of showing, defined as 'picking up a non-food item (for example, moss, small stones, or twigs), holding it up in the beak, head straight or tilted upwards, and staying in this position'," Pika and Bugnyar wrote. "Ten instances consisted of offering, defined as 'picking up a non-food item (for example, moss, small stones, or twigs), holding it up in the beak and moving the head up- and/or downwards repeatedly'."
The scientists ruled out the notion that the ravens were just messing around with the objects because the behaviors only occurred during the interactions with the other partner birds and were accompanied by waiting, watching and paying attention. They also concluded that it wasn't food-sharing behavior -- only once did a raven try to "feed" the object to its partner.
So what were they up to? The scientists believe the birds were demonstrating true gestural communication -- "look at this" behavior. The ravens probably evolved and then practice the ability because of their complex social life, including the long courtship that leads them form permanent pair-bonds. Ravens mate for life, and the partners must work together to dominate large territories against other ravens.
And so marriage -- at least the corvid kind -- may be responsible for turbo-charging the raven knack for communication.
"The motives to form and maintain affiliate relationships may, thus, have been crucial in boosting not only their cognitive but also, especially, their vocal and nonvocal communicative abilities," the authors wrote. "Notably, first stages of social bonding may involve behaviours to direct other's attention triadically and referentially."
Contact Doug O'Harra at doug(at)alaskadispatch.com.