Scientists who study birds’ brains long ago discovered that, just like humans, birds can be right-handed or left-handed.
In humans, dominance on the left side of the brain results in right-handedness and vice versa. Birds’ brains have functional lateralism too and can show behavior that indicates they favor one “hand” over the other.
An easy way to tell this is on birds whose eyes face sideways instead of straight forward (robins, pigeons, etc.) because they obviously use one eye or the other for important tasks. What eye do they use to scan for predators? In 2001, Franklin and Lima found that most dark-eyed juncos use their right eyes.
Crossbills take “handedness” one step further. Their bills cross either to the right or the left. Then they walk around the pine cones on which they feed in a clockwise or counterclockwise direction depending on the “handedness” expressed in their bills.
So, what do you think? Is this crossbill right-handed or left-handed?
(photo of a white-winged crossbill by Raymond Barlow. Inspiration and information from Ornithology by Frank B. Gill)