Home & Garden Columns
Nicola Clayton and her scrub-jays have been at it again. Clayton, as you may recall, is the Cambridge experimental psychologist who keeps making startling claims about the cognitive abilities of the western scrub-jay, a bird she met while at UC Davis. (It’s the most widespread of three closely related species of crestless blue-and-gray jays; the others, the Florida scrub-jay and island scrub-jay, have limited ranges).
It was Clayton who contended that scrub-jays demonstrated episodic-like memory, thought to be a human exclusive: they could recall what they had done where and when, specifically where they had stashed perishable waxworms and more durable peanuts. In the wild, the birds cache and retrieve acorns. They’re not as good at refinding stored food as their corvid relatives the pinyon jay and the Clark’s nutcracker; as Joseph Grinnell observed back in 1936, the acorns the scrub-jays miss may become the next generation of oaks.
It was also Clayton who found evidence for a “theory of mind” in scrub-jays, the ability to think of what others might be thinking. In that case, jays prone to pilfering other birds’ caches returned to move food that they had been observed hiding. The line of thought would be: “If I had seen Ralph hiding that acorn, I’d go steal it; and since he saw me hiding mine…”
Critics objected to both claims, of course, but Clayton’s ingenious experiments made a strong case. Now she’s back, in a recent issue of Nature, with a new study that suggests scrub-jays can plan for the future—again, something only the higher primates, humans and great apes, were supposed to be able to do.
Granted, many animals do things that appear purposeful: they fly north for the spring and south for the winter, swim to Ascension to mate, seek out caves or dens for hibernation, store acorns. But it’s assumed these behaviors are hardwired responses to seasonal cues: the animals are programmed to act in pre-set ways with changes in temperature or daylight.
With Clayton’s jays, something different seems to be going on. Her experiment this time exploited the birds’ caching compulsion.
She designed a three-chambered setup. The jays were kept overnight in the central space, with powdered pine nuts to snack on. In the morning they were moved into one of two adjoining spaces, one with food, the other without.
On their second night in the experimental cages, the jays were given a supply of pine nuts and each side room had a sand-filled ice-cube tray for caching. The birds that had previously missed out on breakfast cached three times as many nuts in the “no-breakfast room” as in the “breakfast room.” They seemed to remember whether they had spent the previous morning in a cozy B & B or in a Motel 6.
What could this be, asks Clayton, but a kind of mental time travel?
“If I thought I’d end up in a grotty motel with no breakfast, I’d take provisions with me”, she told a reporter. (Yes, she’s the kind of person who still says “grotty.” She comes off as a tad eccentric; she is described as somewhat birdlike, and her Cambridge students have classified her as Claytonia professorii. But her experiments are rigorous, and her results have won grudging acceptance among many behaviorists.)
She has had to defend corvid intelligence against her husband and research collaborator Nathan Emery, who worked with primates. She accuses him of making “ape-ist remarks” about his subjects’ supposedly unique abilities, which she saw echoed in her jays.
Clayton, who has also studied the rook, a European crow relative, notes that corvids are among the brainiest of birds: a jay’s brain is proportionally larger than a chimp’s. Size may not be all that important, if cognitive sophistication turns out to be more a function of how the brain is wired. As Bernd Heinrich and other scientists have pointed out, jays, crows, rooks, and ravens have rich social environments, with a myriad of individuals and relationships to keep track of—the same kind of setting that may have driven the evolution of intelligence in us primates.
Although some remain skeptical, it does seem possible that scrub-jays can visualize and plan for the future—at least, a future without breakfast. As far as I know, though, no one yet has approached a jay about life insurance.
Joe Eaton is a former professional gardener and arborist. His “Wild Neighbors” column appears every other Tuesday in the Berkeley Daily Planet, alternating with Ron Sullivan’s “Green Neighbors” column.