New Caledonian crows can tell how heavy an object is simply by seeing it sway in the wind, researchers have found.
The experiment makes crows the first creatures other than humans to have the ability.
Researchers say the animals use the skill to search for food.
‘If we observe an object being blown down the street by the wind, we can infer that it is light,’ the researchers, led by Sarah Jelbert at the University of Cambridge, wrote.
Previous research has found crows have a reasoning ability rivalling that of a human seven-year-old.
‘We reason based on how the wind works: the wind can move light, but not heavy, objects.
‘Do animals make such inferences? We found that New Caledonian crows infer the weight of objects from how they act in the wind.’
Crows were trained that they needed either light or heavy objects.
After observing novel heavy and light object being blown in an (electric fan) breeze, crows interacted with the correct object first, the team found.
‘Overall, our results suggest that these birds are capable of making inferences about the properties of objects in the world around them, without having to directly experience those properties themselves,’ the researchers wrote.