Why Are Some Birds So Smart? Their Brains Are Neurally Dense

Alastair Rae via Wikimedia Commons // CC BY-SA 2.0
Alastair Rae via Wikimedia Commons // CC BY-SA 2.0

Little by little, the well-established myth of the stupid bird is crumbling. Just a few months ago, researchers reported that some birds are as smart as apes. Now another team of scientists say that bird brains pack way more brain cells per square inch than those of primates and other mammals. They published their findings in the Proceedings of the National Academy of Sciences.

The brains of humans and apes include a structure called the neocortex, which houses some of our most sophisticated thought processes and mental tasks. Birds don’t have neocortices at all, and so for years, scientists assumed that meant they were unintelligent. As it turns out, we were just being self-centered. Birds don’t need neocortices; a similar structure called a pallium does their mental heavy lifting.

One bird stereotype is accurate: Compared to, say, a human or a chimpanzee, birds do have little brains. Yet “corvids and some parrots are capable of cognitive feats comparable to those of great apes,” the authors write. “How do birds achieve impressive cognitive prowess with walnut-sized brains?”

To find out, the researchers examined the brains of 28 different bird species, from tiny zebra finches to towering emus. They examined the birds’ brain tissue at a cellular level, measuring the number and distribution of neurons in each region. They compared the neural density to that found in the brains of mice, rats, primates, and artiodactyls (even-toed ungulates).

As it turns out, when it comes to brain cell density, birds have them all beat. The pallium was crammed wall-to-wall with brain cells. Parrot and songbird brains contained twice as many neurons as similar-sized primate brains, and two to four times as many neurons as those of rodents. Birds also dedicate way more brainpower to their pallia than we do to our neocortices. The pallium houses 33 to 55 percent of a songbird’s brain cells, and 46 to 61 percent of a parrot’s. By comparison, the human neocortex hosts only 19 percent of our brain cells.

Senior author Suzana Herculano-Houzel, a neuroscientist at Vanderbilt University, said in a press statement: “In designing brains, nature has two parameters it can play with: the size and number of neurons and the distribution of neurons across different brain centers, and in birds we find that nature has used both of them.”

These findings open a new pathway in understanding how brains evolve. Generally speaking, in order to advance, brains have had to get bigger, and bigger brains are linked to more cognitive capacity. But, Herculano-Houzel said, “bird brains show that there are other ways to add neurons: keep most neurons small and locally connected and only allow a small percentage to grow large enough to make the longer connections."

But no evolutionary advantage is truly free. Does a denser bird brain require more energy to run than ours, which are spacious by comparison? If so, where is that energy coming from?

“Something I love about science is that when you answer one question, it raises a number of new questions,” said Herculano-Houzel.

Toronto, 'Raccoon Capital of the World,' Is Fighting Its Trash Panda Problem ... and Losing


Toronto’s “raccoon-resistant” garbage cans aren’t as effective as city officials hoped. As NPR reports, the self-proclaimed “raccoon capital of the world” has been unable to outwit some of the city’s cleverest "trash pandas."

For years, Torontonians have struggled to contend with the city’s booming raccoon population and its insatiable appetite for old pizza, overripe bananas, and just about everything else that gets thrown out with the trash. In 2016, the city spent CA$31 million (about US$24 million) on waste bins that were specially designed to keep furry scavengers out. To open one up, a rotating handle on the lid must be turned to unhinge a gravity lock. The hope was that raccoons, which lack opposable thumbs, wouldn’t be able to break in.

Cameras cast doubt on that theory. In a heist that would make National Treasure's Nicolas Cage proud, footage uploaded to YouTube by the Toronto Star shows a determined mama raccoon cracking the code to open the lid and get to the good stuff inside.

Even without thumbs, raccoons have nimble paws. On top of that, urban raccoons boast some serious street smarts. One study by raccoon expert Suzanne MacDonald revealed that raccoons knew to avoid busy intersections, and another study found that city raccoons are better than their country counterparts at figuring out how to open garbage can lids.

Research from the early 1900s showed that raccoons could crack 11 out of 13 locks—which included latches, levers, buttons, hooks, and bolts—to open a box with food inside. As for the episode seen above, Toronto officials and an employee from the garbage can company said broken bins are to blame. The faulty bin was replaced, but the camera kept rolling, and footage showed that raccoons were able to knock over and break into the new bin, too.

This time, the bin manufacturer blamed the breach on a faulty handle. On the bright side, the city reported that these break-ins aren’t widespread. Out of nearly 500,000 bins, only 24 raccoon-related problems were reported.

MacDonald has been tracking whether the city’s “very fat” raccoons have lost any weight since the new bins have been rolled out. While the results aren't yet conclusive, “they’re not starving to death, that’s for sure,” she told Toronto Star reporter Amy Dempsey.

[h/t NPR]

How You Can Help Animals Affected by Hurricane Florence


If you've ever considered rescuing a pet, now's the time to take the plunge: You could save an animal's life if you choose to adopt from a shelter in the path of Hurricane Florence.

With the Category 1 storm making landfall over the Carolinas this week, government officials have urged as many as 1.7 million residents to evacuate their homes. As a result, local animal shelters are scrambling to find homes for abandoned pets before the worst of the storm hits, and if they aren't able to place them in time, some animals will have to be euthanized.

That makes now the perfect time to adopt a pet if you're in the position to do so. Some shelters, like the Pender County Animal Shelter in Burgaw, North Carolina, have even waived their adoption fees in an effort to encourage more people to take pets home.

If you can't make a commitment to owning a pet at this time, fostering is also an option. Most shelters in the storm path will gladly place pets with someone who can give a dog or cat shelter until it's safe for them to return to the area. And if that's still not a possibility for you, you can help shelters by making a monetary donation. Transporting pets and making sure they're spayed, neutered, and vaccinated costs money, and shelters can use donations to help more pets get out the door and into safe homes.

The Charleston Animal Society, the Greenville Humane Society, the Humane Society of Charlotte, and the Pender County Animal Shelter are just a handful of animal shelters in need of assistance. You can also look at specific requests for support local shelters have made through this website.