The stereotype is true: Bird brains are much smaller than their human counterparts. And yet they still pack a proportional punch. Many birds have craniums that are big for their body size—an important and costly evolutionary trait. (Brain cells are extraordinarily greedy, and require up to 10 times their percentage in weight in oxygen and blood flow.)
But what's a bird need all those cells and neurons for? The list is near endless, according to veteran science writer Jennifer Ackerman, who explores the different forms of avian intelligence in her new book, The Genius of Birds. Ackerman seeks out the brainiest species and reveals their unique mental abilities through fascinating anecdotes—from mockingbirds that learn hundreds of "languages," to pied babblers that "kidnap" chicks from other families. Audubon discussed these stories with Ackerman via email, along with the many mysteries that still surround birds and their intelligence.
Audubon: Birds and mammals have been on separate evolutionary paths for over 300 million years, yet they still share some skill sets, such as the ability to use tools. How?
Jennifer Ackerman: For centuries, we thought there was only one way to wire a clever brain that's capable of our kind of complex thinking. You had to have a cortex, with layers of neurons like we have. But it turns out that birds have evolved a different but quite remarkable system for generating sophisticated, flexible thinking, right alongside ours. Both bird brains and human brains [are asked] to meet some of the same challenges in nature and solve some of the same problems, both ecological and social. How do I obtain hard-to-get foods? How do I get along with others? How do I defend my territory?
A: What can bird brains do that human brains can't?
JA: Birds are far more gifted than we are at navigating. Consider the White-crowned Sparrow. In one study, scientists plucked a small flock of these sparrows from their migratory path on the West Coast and transported them by jet 3,000 miles across the country to New Jersey. Within hours the little birds were beelining it, solo, back to their wintering grounds in southern California and Mexico—even the young ones, who had only made the migratory journey once. They knew just where to go and just how to get there—without the help of technology. I don't know many humans who would pass that test.
A: What can we learn from the study of bird intelligence?
JA: We can learn something about how our own brains work. Birds learn and remember. They use calls and songs to communicate. They locate themselves in space and position themselves in social groupings, from family units to flocks of hundreds or thousands. Their brain waves show the same pattern as ours during sleep. They deceive and manipulate. They play games. They console one another. Birds are great models for understanding our own mental processes—how we learn language, for instance, or how speech evolved in the first place.
A: You encountered many fascinating birds in person. Did you have a favorite?
JA: My favorite encounter was with New Caledonian Crows. I’d read so much about this bird and its tool-making and problem-solving abilities. To see it cracking nuts in the rainforest and then close up in a research aviary, fashioning a twig tool perfect for the task at hand—that was thrilling.
A: What was the most surprising thing that you learned?
JA: I’d say I was most surprised by the amazing complexity of Black-capped Chickadee communication. Scientists have studied the whistles and gargle calls of chickadees, and declared their system of communication among the most sophisticated and exacting of any land animal. When you pass a chickadee, note the number of dees in its call; they're conveying to other chickadees your size and degree of threat.
I was also surprised and delighted by the unexpected spatial genius of Rufous Hummingbirds. They can register the location of a flower in large featureless field by visiting it once for only a few seconds. They can also remember whether or not they’ve visited a particular flower, and can gauge how long it will be before that flower refills its nectar.
A: When talking animal minds, scientists often either anthropomorphize—aka universalize human experience—or present human traits as special and unique. Where do you stand?
JA: The truth is our mental abilities, like those of every other creature, are the products of evolution over a long time. We share a surprising amount of biology with other creatures, including birds. We also share similar challenges in getting along in the world and in some cases, have come up with similar solutions, whether biological or behavioral. More and more research is showing that the behaviors we thought were unique to humans—planning, problem-solving, reasoning, learning, teaching, empathizing—are shared by other organisms. But they use them in their own unique ways to survive.
This interview has been edited for length and clarity.
The Genius of Birds, by Jennifer Ackerman, Penguin Press, 352 pages, $28. Buy it at Powell's Books.