This ability is one of a number discovered in crows. They also include the fashioning and use of tools to access food.
A video of the experiment shows a crow looking around to the plastic sheet 12 times if it lacked the reassurance that potential stick-pokers had left the area.
"We didn't really think the crows would be able to do this. We thought it would be a nice experiment to show the limitations of a corvid [crow] brain," Dr Taylor said. "A lot of people have studied this kind of thinking [in humans] and made strong claims that no other animal could do it."
The experiment was part of a larger project to better understand the unique intelligence of humans and how intelligence evolved.
Clever bird
New Caledonian crows have shown:
* Advanced tool use - such as making hooks out of wire.
* A form of culture, with toolmaking styles varying by location.
* Unusually big brains.
* Nuclear families, including apparent affection for one another.
* The ability to deduce hidden causality.
Watch Alex Taylor discuss his research