Ravens (Corvus corax), and corvids in general, are renowned for their repertoire of ‘intelligent’ behaviour, including tool use and complex sociality. Research published online today describes a previously unknown facet of raven behaviour.
The use of referential gestures, such as holding or pointing to objects to attract attention, has long been considered a skill unique to humans and our closest relatives, the great apes. However, such behaviour has recently been observed in ravens. This is not the first instance of ravens exhibiting cognition to rival non-human primates (Prof. Jerry Coyne has a great piece, with videos, here).
The paper, in Nature Communications, describes the use of ‘referential gestures’ in wild ravens (Corvus corax), and the affiliative interactions induced by such behaviour. The authors observed ravens performing two distinct behaviours – ‘showing’ and ‘offering’. When ‘showing’, ravens picked up inedible items (such as moss and twigs) in their beak, with head tilted upward, and remained in this position to display the item to a conspecific. ‘Offering’ behaviour consisted of presenting an object in much the same way as when ‘showing’, followed by movement of the head up and down repeatedly. Such behaviour was always directed toward a recipient, and elicited a response in 100% of observations – the vast majority of which were affiliative (i.e. approaching, billing, mutual manipulation of object).
The authors hypothesise that convergence on referential gesturing in such unrelated groups as corvids and primates highlights the role of cooperative motives in the evolution of complex modes of communication. Further, if one follows this to it’s logical conclusion, one day we may have talking crows! Another fantastic reason to conserve the biodiversity on our fragile planet.
This discovery, however, is just the tip of the iceberg – the latest of numerous recent findings in animal behaviour that are challenging the notion of the intellectual superiority of primates over other animals. For example, tool use has been observed in numerous birds, a species of dolphin, a fish and even an invertebrate. These examples all serve to put into perspective the nature of those behaviours that, when observed in human-like organisms, are lauded as “intelligent” and “advanced”; they are evolutionary adaptations unlike any other, capable or arising in a myriad species.
Here are my personal favourite videos of less ‘intelligent’ species trivialising ‘complex’ vertebrate behaviour:
‘Tool use’ in a sparrowhawk
Courtship display of the peacock spider
Pika, S., and T. Bugnyar. 2011. The use of referential gestures in ravens (Corvus corax) in the wild. Nature Communications 2:560