Credit: ELSEVIER

Curr. Biol. doi:10.1016/j.cub.2009.02.062 (2009)

Curious as to whether jackdaws — members of the crow family — could follow human eyes, Auguste von Bayern and Nathan Emery, then at the University of Cambridge, UK, offered food to hand-raised jackdaws. The birds took longer to nab a proffered nibble if the food was the subject of a stranger's stare, and they seemed to be watching the eyes rather than the direction of the head (see variations of head and eye attitudes, pictured). In a separate experiment, the birds needed moving, rather than static, eye signals from a familiar person to understand communication about the location of hidden food.

The researchers speculate that jackdaws evolved this eye-following ability to interact with one another. However, they add that the birds followed by the study have spent their whole lives with humans.