Friday, April 19, 2013

Gestural communication in a non-primate

Originally written December 2011


Ravens the First Non-Primate Shown to
Perform Communicative Gestures Too

A study published last month in Nature Communications [November 29, 2011] shows the first evidence of gesturing in a non-primate. While drawing others’ attention to objects begins as early as one year of age in humans, observations of comparable gestures in our closest relatives, the great apes, are relatively rare and come primarily from captive or human-raised individuals. Such sophisticated communication involving understanding another’s perspective on the world and how it relates to one’s own has long been considered an ability unique to primates.

Simone Pika from the Max Planck Institute for Ornithology and Thomas Bugnyar of the University of Vienna, however, have shown otherwise. The conclusion of a two-year study shows that wild ravens (Corvus corax) use non-vocal gesturing with their beaks to show and offer moss, stones, and twigs to others, usually partners of the opposite sex. Following the gesture, the recipient frequently oriented towards the object before interacting with it alongside the signaler. Pika and Bugnyar observed a wild colony in Cumberland Wildpark in GrĂ¼nau, Austria, indicating that the gesturing communication reflects natural behaviors. 
 
Ravens are a member of the corvid family, along with crows, jays, and over a hundred other songbird species. Corvids have brains as big as primates relative to their body size and score similarly high on intelligence tests. Yet, corvids arrived at this level of intelligence independently of the hominid lineage. The ecological and evolutionary significance of corvid cognition remain to be understood, as large intelligence is developmentally and metabolically costly. With abilities once thought unique to humans continuing to be discovered in other species, we may find the intellectual gap between us and the rest of the world not as large as we once thought.  

Original Article
Pika S and Bugnyar T. (2011). The use of referential gestures in ravens (Corvus corax) in the wild. Nature Communications. 2: doi:10.1038/ncomms1567
 

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