Researchers Discover Jackdaws Use Their Eyes to Communicate With Each Other

Posted on February 5, 2014

Bright eyes of the jackdaw

Researchers from Cambridge and Exeter have discovered that jackdaws use their eyes to communicate with each other. This is the first time the behavior has been shown in non-primates. Jackdaws user their intense bright eyes as warning signals to deter other birds from coming near their nests.

Gabrielle Davidson of the University of Cambridge, who led the study, said in a statement, "Jackdaw eyes are very unusual. Unlike their close relatives, the rooks and crows - which have very dark eyes - jackdaw eyes are almost white and their striking pale irises are very conspicuous against their dark feathers."

To test the birds researchers put four different pictures in 100 jackdaw nest boxes on the outskirts of Cambridge. The pictures were either black (the control), a pair of jackdaw eyes, a pair of jackdaw eyes in a jackdaw's face, or a jackdaw's face with a pair of black rook eyes. The researchers video taped the birds to study their reactions to the pictures. The researchers found that the picture of a jackdaw with its bright eyes was most effective at detering birds.

Davidson says, "Jackdaws are unique among the crow family in that they nest in cavities in trees. These hollows are natural - the birds cannot excavate their own nest cavities as some woodpeckers do - so they have to compete for a limited resource. And because jackdaws nest in close proximity to each other, they fight a lot to gain the best nesting sites."

A research paper about the findings was published here in Biology Letters. Take a look:

Photo: © Richard Woods

More from Science Space & Robots