The California Scrub-Jay, a generally non-social bird, can learn just as well as another species of jay that lives in groups, a finding that surprised animal intelligence researchers who devised a novel food puzzle to study cognition in the wild.
The research illustrates the complexity of the link between social behavior and the evolution of intelligence, say the scientists, who had expected the group-oriented Mexican Jay to outperform the scrub-jay.
The University of California Santa Barbara’s Kelsey McCune led the study when she was at the University of Washington. Her team included researchers from Oregon State University, the University of Washington, and Seoul National University in South Korea. Findings were published in Nature Scientific Reports.
The researchers put bird food behind four different types of doors on two identical puzzle apparatuses, each fashioned from a log. Three of the four doors had a simple lock; the other was unlocked but contained a less-desirable type of food – sunflower seeds rather than peanuts.
The researchers trained “demonstrator” birds of each species how to open a locked door and then set about looking at the learning abilities of wild, banded jays: 49 Mexican Jays, which were studied near Portal, Arizona, and 26 California Scrub-Jays, observed in Oregon’s Willamette Valley.
“Having an unlocked door helped prevent ‘naïve’ jays from abandoning the foraging area due to a failure to get food, thus increasing their probability of observing group mates interacting with the puzzle,” co-author Jonathon Valente of Oregon State University said.
Mexican Jays and California Scrub-Jays are closely related, McCune notes – both feed on tree nuts like acorns, are opportunistic, generalist foragers that like dry, open habitats of pine and scrub oak, and cache food at a similar rate.
But they have very different social systems: Mexican Jays assemble in groups of five to 30, while the relatively non-social scrub-jays mainly live with a single mate.
“We compared intelligence between these species by testing their abilities to either innovate a solution to the puzzle or to learn to solve the puzzle by observing other birds solving it,” McCune said. “Contrary to what we thought we’d find out, the two species showed similar abilities to learn.”
Mexican Jays tended to learn through watching others interact with the puzzle, whereas scrub-jays relied more on individual problem-solving to get at the food.
Valente adds: “The findings suggest the relationship between social behavior and the evolution of intelligence is a highly complex one. Further studies with wild animals are clearly necessary to develop a better understanding of when, where and why intelligence evolved.”
Thanks to Oregon State University for providing this news. A version of this article appears in “Birding Briefs” in the May/June 2022 issue of BirdWatching magazine.