Talk about learning on the fly: A new study shows that the great-tailed grackle is a remarkably nimble problem-solver.
When presented with puzzles that contain food as a prize, grackles deploy different learning strategies to solve the problem. What’s more, when the rules of the puzzle change, these Central American birds roll with the punches, quickly switching up their strategies to win food once more. (Also see "Clever New Caledonian Crows Use One Tool to Acquire Another.)
This skill, called behavioral flexibility, is still poorly understood in non-humans because it’s difficult to separate it out from sheer problem-solving ability, or how quickly one can perform a task. That makes the grackle study, published in PeerJ on May 3, all the more important for learning the details of bird intelligence.
“When you have a hammer, every problem starts to look like a nail,” says Corina Logan of the University of Cambridge, the study’s sole author and a National Geographic/Waitt grant recipient. “Behavioral flexibility is when you use the right tool for the job.”
Young, Scrappy, and Hungry
Logan, who conducted the research while at the University of California, Santa Barbara, first encountered grackles in Costa Rica, part of the birds’ native range.
She realized that they were pretty smart, despite their lack of relation to corvids, the legendarily clever bird group that includes crows and ravens. (See "Are Crows Smarter Than Children?")
“They’d walk right up to you, and stare at you, like they were waiting for you to drop food,” she says. “I remember thinking, ‘Gosh, these look like smart crows,’ but they’re not crows at all.”
It didn’t surprise Logan that grackles were intelligent: in the last 200 years, she says, the highly social birds have expanded their Central American range by more than 5,000 percent, thriving in cities across the southwestern United States.
Logan wanted to put their skills to the test, so she temporarily captured eight adult grackles from parks around Santa Barbara, California, and presented them with two puzzles designed to test their nimbleness and problem-solving skills.
One, inspired by Aesop’s fables, teased grackles with food floating on water just outside of the bird’s reach, forcing the birds to throw large pebbles into the container to raise the water level.
The other test presented individual grackles with two differently colored holes, one of which led to a food cache. These tests are commonly used to test behavioral flexibility in other animals, and correspond to situations in the wild when grackles experiences changes in their environment, like the movement of a food source. (Discover how a crow solved a challenge from Aesop's fables.)
Birds of a Feather Don't Flock Together
The grackles sailed through the problems, successfully finding the food—but then Logan threw the birds two curveballs.
In the Aesop’s fable test, Logan swapped out the large pebbles with fakes that wouldn’t enter the water at all, forcing the birds to use less ideal small pebbles to get the food. She also swapped the colors on the two holes, forcing the birds to relearn which color corresponded with food.
The birds largely made the switch successfully, demonstrating that they could adapt quickly to new challenges.
But surprisingly, an individual grackle’s nimbleness didn’t have much bearing on their problem-solving skill or speed, implying that behavioral flexibility is an entirely separate skill.
Moreover, the grackles didn’t approach the problems, or the changes, in the same way—demonstrating individual learning quirks in ways that are all too familiar. (See National Geographic’s photos of brainy animals.)
“[Logan] clearly demonstrated variability that different individuals have when it comes to learning,” says John Marzluff of the University of Washington, an expert in bird behavior who wasn’t involved with the study.
“That’s really cool. You’d see the same thing in people.”
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