Curious crows use tools to explore dangerous objects
By Ella Davies
Earth News reporter
What happens when a New Caledonian crow meets a toy rubber spider?
New Caledonian crows use tools to investigate unfamiliar and potentially dangerous objects, according to scientists.
New research shows crows cautiously investigating new objects using sticks as an extension of their beaks.
New Caledonian crows are known to fashion tools to access food sources such as wood-boring beetle larvae.
Scientists suggest this study is the first time birds have been recorded using tools for multiple purposes.
The crows were using tools to learn about the object which was novel, and potentially dangerous, without making direct contact
Dr Jo Wimpenny University of Oxford, UK
The findings are published in the journal Animal Cognition.
New Caledonian crows (Corvus moneduloides) are known for their intelligent and innovative use of "tools", such as twigs, to extract nutritious insects from hard to reach places.
Studies have also revealed that the crows will craft tools into more suitable shapes and use more than one in order to reach food.
To understand more about their behaviour, researchers from the University of Oxford, UK, introduced a group of crows to a variety of objects including a rubber snake, a flashing LED bike light and a tin of paint.
The research team aimed to study how the crows reacted to objects that were not associated with food.
To this end, researchers placed unfamiliar objects into the birds' aviaries without their knowledge to avoid any associations between human interaction and food.
A crow uses a stick to investigate a potential snake
"We presented our crows with a range of novel objects and found that some crows first contacted the objects with a tool, rather than their beak," explains Dr Jo Wimpenny.
Dr Wimpenny believes this behaviour shows a previously unrecorded use of tools in New Caledonian crows.
"The crows were using tools in an information-gathering context; i.e. in order to learn about the object which was novel, and therefore potentially dangerous, without making direct contact," she says.
"We might do the same if we were out walking in the woods and came across a strange object that we had never seen before - safer to prod it with a stick than with our fingers!"
Crows and other members of the corvid family are remarkably intelligent
New Caledonian crows are members of the corvid family which includes magpies, rooks and ravens.
With relatively large brains, corvids are considered highly intelligent but none demonstrate innovative problem-solving quite as complex as that of New Caledonian crows.
Scientists suggest that the crows could be regarded in even higher esteem: as the only birds that use tools for more than one purpose.
"Only a few species, other than humans, use tools to achieve multiple functions, so our observations are exciting because they suggest that New Caledonian crows may also qualify to join this small group," says Dr Wimpenny.
Dr Wimpenny explains that by using tools for more than one function, New Caledonian crows demonstrate that avian brains could be more complex than previously thought.
"Up until now, no species of bird has been reported using tools to achieve more than one function, and that might suggest that avian tool use is a narrowly programmed adaptation that has evolved for one purpose - typically food extraction," she says.
"The use of tools for multiple purposes - in this case extractive foraging and information-gathering - would suggest that tool use is under a broader level of control, involving higher-level cognitive operations and greater flexibility in information-processing."