CBR scientist Professor Russell Gray and colleagues have recently shown through their research that New Caledonian Crows, already known to be remarkably advanced birds (they utilise tools, for instance), are even sharper than previously thought.
The team set up an experiment in which the crows were exposed to two slightly different ‘strange scenarios’ (a stick appeared from behind a screen in their cage and waved about). In one case, the birds saw a person enter and exit the area behind the screen. In the other, the ‘waver’ entered and exited by a different route invisible to the birds. The birds behaved very differently when the stick waved about with apparently no agency – they appeared nervous and kept glancing toward the screen from which the stick had protruded.
Professor Gray and his colleagues concluded that the crows were engaging in ‘causal reasoning’ – they understood that sticks do not usually appear and wave about all by themselves, and therefore inferred that something or someone was doing the waving, even though they could not confirm this through their sensory systems.
Scientists from around the world have hailed the design of this study as a crucial advance in investigating causal reasoning in non-human populations. You can read more about what they have said and the details of the study design, by clicking the link below.
The full text of the article, published online in the Proceedings of the National Academy of Sciences, may be viewed here: