Five species that show why ‘bird brain’ is a stupid phrase

pigeon in an experiment setup

Pigeons are more than just annoying “flying rats.” Scientists trained the birds to recognize malignant breast tumors. 

Copyright Wassermann Lab/Univ. Iowa

Call someone a “bird brain” and they are sure to be offended. After all, it’s just another way of calling someone “stupid.” But it’s probably time to retire the insult because scientists are finding more and more evidence that birds can be pretty smart. Consider these five species:


We may call pigeons “flying rats” for their penchant for hanging out in cities and grabbing an easy meal. (Long before there was “pizza rat,” you know there had to be “pizza pigeons” flying around New York City.) But there may be more going on in their brains than just where to find a quick bite. Richard Levenson of the University of California, Davis Medical Center and colleagues trained pigeons to recognize images of human breast cancers. In tests, the birds proved capable of sorting images of benign and malignant tumors. In fact, they were just as good as humans, the researchers report November 18 in PLOS ONE. In keeping with the pigeons’ reputation, though, food was the reward for their performance.

New Caledonian crows

No one would suspect the planet’s second-best toolmakers would be small black birds flying through mountain forests on an island chain east of Australia. But New Caledonian crows have proven themselves not only keen toolmakers but also pretty good problem-solvers, passing some tests that even dogs (and pigeons) fail. For example, when scientists present an animal with a bit of meat on a long string dangling down, many animals don’t ever figure out how to get the meat. Pull it up with one yank, and the meat is still out of reach. Some animals will figure out how to get it through trial and error, but a wild New Caledonian crow solved the problem — pull, step on string, pull some more — on its first try.

African gray parrots

Alex, an African gray parrot that lived in the lab of Irene Pepperberg, now at Harvard, showed an enormous capacity for learning, eventually garnering a huge vocabulary and the ability to add numbers before his death in 2007. But another of Pepperberg’s birds, Griffin, has shown himself to also be a star pupil. Griffin has an impressive vocabulary that includes the names of objects, shapes, colors and numbers. And Pepperberg has compared the bird’s intelligence with that of a kindergartener. Griffin has even managed to pass a version of the “marshmallow test,” a feat the many young children fail.

bowerbird nest
To attract a female, a male bowerbird will decorate his nest with whatever he can find. shoe_scraper_of_death/Flickr (CC-BY-ND 2.0)

The 20 species of bowerbirds get their name from the males’ courting behavior: To attract a female, he creates an elaborate nest, or bower, that he decorates with any number of found objects. He will spend hours arranging the bits of glass, stone, shells, flowers, berries and even trash discarded by humans into an attractive display. Some species will paint the walls of the bower with charcoal or chewed berries. Others employ optical illusions that may enhance the way the guy appears to prospective ladies. Scientists aren’t sure whether it’s a cognitive behavior or a hard-wired one, but if it’s the former, then a female choosing the best illusion would also be picking the smartest guy.


This is difficult for a poultry-eater to admit, but chickens are far more intelligent than most people realize. The birds can be deceptive and cunning, especially subordinate males who want a chance with a female. Chicks can do simple addition and subtraction. They can communicate with each other with sophisticated signals that incorporate both sound and action. And they appear to think before they act.

And all this makes me wonder: If chickens and other birds are simply dinosaurs that didn’t go extinct, how smart was T. rex and all of its huge brethren so many million years ago? Did survival mean having strategy and smarts? We’ll probably never know. But it’s fun to imagine.

Sarah Zielinski is the Editor, Print at Science News Explores. She has a B.A. in biology from Cornell University and an M.A. in journalism from New York University. She writes about ecology, plants and animals.

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