Hear a word, particularly an important one — like “snake!” — and an image appears in your mind. Now scientists are finding that this basic property of human language is shared by certain birds and, perhaps, many other creatures.
In a series of clever tests, a researcher has found that birds called Japanese tits not only chirp out a distinctive warning for snakes, but also appear to imagine a snake when they hear that cry. This glimpse into the mind’s eye of a bird hints at just how widespread this ostensibly human-like capacity may be.
“Animal communication has been considered very different from human speech,” says Toshitaka Suzuki, an ethologist at Japan’s Kyoto University. “My results suggest that birds and humans may share similar cognitive abilities for communication.”
Perhaps this went unappreciated for so long, says Suzuki, simply because “we have not yet found a way to look at the animals’ minds.”
Over the last several years, Suzuki conducted a series of experiments deciphering the vocalizations of Japanese tits — or Parus minor, whose family includes such everyday birds as chickadees and titmice — and describing their possession of syntax, or the ability to produce new meanings by combining words in various orders. (“Open the door,” for example, versus “the open door.”)
Syntax has long been considered unique to human language, and language in turn is often thought to set humans apart from other animals. Yet Suzuki found it not in a bird typically celebrated for intelligence, like crows or parrots, but in humble P. minor.
Once he realized that birds are using their own form of language, Suzuki wondered: what happens in their minds when they talk? Might words evoke corresponding images, as happens for us?
Suzuki tested that proposition by broadcasting recordings of P. minor’s snake-specific alarm call from a tree-mounted speaker. Then he analyzed the birds’ responses to a stick that he’d hung along the trunk and could manipulate to mimic a climbing snake.
If the call elicited a mental image, Suzuki figured the birds would pay extra-close attention to the snake-like stick. Indeed they did, he recently reported in the journal Proceedings of the National Academy of Sciences.
In contrast, when Suzuki broadcast a call used by tits to convey a general, non-specific alarm, the birds didn’t pay much notice to the stick. And when he set the stick swinging from side to side in a decidedly non-snakelike manner, the birds ignored it.
“Simply hearing these calls causes tits to become more visually perceptive to objects resembling snakes,” he writes in PNAS. “Before detecting a real snake, tits retrieve its visual image from snake-specific alarm calls and use this to search out snakes.”
Rob Magrath, a behavioral ecologist at Australia National University who specializes in bird communication, thinks Suki’s interpretation is consistent with the results. He also calls the work “truly delightful.”
“I love the way that Suzuki employs simple experiments, literally using sticks and string, to test ideas,” Magrath says. Similarly impressed is ecologist Christine Sheppard of the American Bird Conservancy. “It’s incredibly challenging to devise an experiment that would allow you to answer this question,” she says. “It’s really neat.”
Minds of Their Own
Sheppard says it makes evolutionary sense for animals to possess a ‘mind’s eye’ that works in tandem with their communications: It allows individuals to respond more quickly to threats. Suzuki agrees, and believes it’s likely found not only in P. minor and their close relatives, but in many other birds and across the animal kingdom.
“Many other animals produce specific calls when finding specific types of food or predators,” he says. He hopes researchers will use his methodology to peek into the mind’s eyes of other animals.
For Sheppard, the findings also speak to how people think about birds: not just as pretty or interesting or ecologically important, but as fellow beings with rich minds of their own.
“When I was in school, people still thought that birds were little automata. Now “bird brain” is becoming a compliment,” she says.
“I think this kind of insight helps people see birds as living, breathing creatures with whom we share the planet,” she says.
Brandon Keim is a freelance journalist specializing in animals, nature and science, and the author of The Eye of the Sandpiper: Stories From the Living World. Connect with him on Twitter, Instagram and Facebook.