National Geographic

BIRD BRAINIACS 121Muppet understand what had changed and beginwith the third lock, the bolt? “We want to knowif they’re solving the problem robotically or ifthey’re paying attention to how the locks work.”Muppet studied the locks for a moment, thentackled the bolt, using his beak to pull it througha ring that kept it in check. Next he twisted off thewheel and pulled back the sliding bar. The doordropped open, and Muppet seized the nut.“Once they figure out a problem, they usuallyremember how to solve it,” Auersperg said. “Theyknow how each lock works, even if they’re out ofsequence. I think they do understand the effectthe locks have on each other; their minds are flex-ible that way.”BIRDS—ESPECIALLY CORVIDS and parrots—are now celebrated as “feathered apes,” biolo-gist Emery says. Emery, who began his career asa primatologist, coined that term for corvids ina paper he co-authored with Clayton, his wife.They’d previously collaborated on a study thatshowed scrub jays didn’t instinctively re-hidenuts from other spying jays; they only began tomove their stash after they stole nuts from theirfellows. “It was the experience of stealing thatchanged the jays’ behavior,” Emery says. “Youknow, ‘It takes a thief to know a thief.’ ” Theirstudy suggested that the jays might understandwhat another bird was thinking (and plotting),a type of reasoning that’s extremely difficult tostudy and demonstrate in other animals.Emery and Clayton argue that corvids andapes evolved markedly similar complex cognitiveabilities even though they’re distantly related—the two groups diverged more than 300 millionyears ago—because they face similar pressures.Both live in social groups, which require an un-derstanding of others’ motives and desires, andthey search for and process a range of foods,some of which can only be acquired by firstmaking a tool. Chimpanzees, orangutans, and