A journal article published this month on New Caledonian crows was co-first authored by Somerville alumnus Zackory Burns (2014, Zoology).
‘Monocular Tool Control, Eye Dominance, and Laterality in New Caledonian Crows’, the article published in the journal Current Biology, argues that New Caledonian crows, which are famous for their ability to manufacture and use tools, tend to be left-beaked or right-beaked according to which eye is dominant. The article summary can be accessed on the journal’s website.
New Caledonian crows extract larvae from burrows using sticks clasped in the beak. The team revealed that the burrow dimensions in nature primarily allow monocular vision while tools are being used, leading to the prediction that eye dominance could be responsible for placing the tool on the left or right side of the bill. Eye dominance and lateral placement of tools in crows is 50/50; this finding contradicts that of humans, who are two-thirds right-eye dominant and 90 percent right-hand dominant.
“The study explains that, while humans have the ability to move hand and eye independently of each other, such as when aligning a shot in archery, the crows’ use of tools in their bills is always in the same orientation to the eyes,” said Burns. “This difference could explain why there is population level laterality in human tool use but not in birds.”
Zackory Burns completed his undergraduate degree at Princeton University and his DPhil at Somerville. He is now the Hellman Fellow in Science and Technology Policy at the American Academy of Arts and Sciences; a Tutor at Adams House, Harvard College; and a Teaching Fellow at the Harvard Extension School. His Harvard profile page can be accessed here.