Biologists have figured out how the New Caledonian crow, a bird famed for using tools, does its party trick.
Corvus moneduloides, a native of France's South Pacific territory of New Caledonia, is one of the stars of the avian world.
It uses its beak to craft complex tools from sticks, leaves and other material, then inserts them into deadwood or vegetation to fish out insects and other food.
Researchers led by Jolyon Troscianko of the University of Birmingham in England used an ophthalmoscope video camera to record field of view and eye movement as three wild-caught birds examined a baited tube.
The bird's eyes were more forward than sideways-positioned, giving it exceptional "binocular overlap", they found.
This is the area that is viewed by both eyeballs, and is important as it helps the brain judge the distance of nearby objects.