Bird brains (2023)

I was doomscrolling Reddit at 1am (as you do) and someone had posted a video from the New Zealand Transport Agency. Road workers near a tunnel by Milford Sound kept finding their traffic cones in weird places. Dragged into the road, rearranged, sometimes actively rerouting traffic. Nobody could figure out what was going on, so they checked the cameras.

Kea. Native to New Zealand, these big parrots are usually seen on the route to Milford Sound harassing tourists. A flock of them is officially called a "circus" or a "curiosity" -- whoever named them clearly met one. The footage showed them just... casually shoving cones around a construction site. But here's the insane bit -- workers said the kea would listen for cars coming through the tunnel BEFORE moving the cones, timing it so the cars would have to stop. Why? Because stopped cars mean humans getting out. Humans getting out means food.

These birds are smarter than some adults I know. Move cone → car stops → human gets out → human feeds me. They independently invented toll booths.

The transport agency's solution was equally funny. They switched to heavier cones the birds couldn't move, and then -- I'm not making this up -- they built "kea gyms" by the roadside. Puzzle stations and contraptions to keep them entertained. A government agency literally built a playground for parrots because they were too smart for traffic management. Honestly, I'm fine with my tax dollars going to this.

Obviously now I had to know -- is this the smartest bird in the world? And hold on, how do you actually measure how smart a bird is? So I whipped out ChatGPT and Google Scholar and here's what I learned.

How do you give an IQ test to a bird?

Turns out there's no single test -- researchers have come up with a bunch of different experiments over the years, each designed to measure a different type of intelligence. Some of these I'd fail too tbh.

First up, the mirror test. You stick a coloured mark on a bird somewhere it can only see in a mirror. If it looks at the mirror and then tries to remove the mark from its own body, it recognises that the reflection is itself. That's self-awareness. Most animals completely fail this -- dogs fail it, cats fail it. Eurasian magpies pass it. One of the very few non-mammals to do so. Your local magpie has a stronger sense of self than your golden retriever. Pretty humbling for the dog.

Then there's a cool one called Aesop's Fable -- my favourite. It's literally named after the fable where a thirsty crow drops stones into a pitcher to raise the water level. Researchers put food floating in a narrow tube of water that the bird can't reach. The question is whether it'll figure out to drop objects in to raise the water level and get the food. Rooks, New Caledonian crows, and Eurasian jays all pass. Some of them even figure out that heavy objects sink (useful) whilst light objects float (useless). A fable from 600 BC and it turns out Aesop was just reporting the news.

Next, the delayed gratification test. The marshmallow test, but for birds. Offer an OK snack now, or a much better snack if they wait. Ravens pick the better future reward over 70% of the time. They'll even choose a tool they'll need later over an immediate food reward. That's more self-control than I have around a bowl of chips.

There's also vocal mimicry and communication, which goes way beyond "Polly wants a cracker." Dr. Irene Pepperberg studied an African grey parrot named Alex for 30 years. Alex could identify objects, colours, shapes, and numbers. He understood abstract concepts like "same" and "different." His vocabulary exceeded 100 words. When he died in 2007, his last words to Pepperberg were reportedly "You be good. I love you. See you tomorrow." I don't care how you define intelligence -- that one's hard to brush off.

And finally, spatial memory. Clark's nutcrackers cache up to 33,000 seeds across thousands of locations each autumn -- and remember where most of them are months later. I lose my keys in a two-bedroom apartment.

The "bird brain" insult is backwards

Here's the wild part. A 2016 study in PNAS found that parrots and songbirds pack roughly twice as many neurons into their forebrains as primate brains of the same mass. The neurons are just much smaller and more densely packed. A crow's brain weighs about 10 grams. A chimpanzee's weighs about 400 grams. And yet corvids demonstrate cognitive abilities that rival great apes: tool use, planning, and social reasoning.

A macaw's brain weighs 20 grams and has roughly the same number of forebrain neurons as a macaque monkey's brain at 70 grams. Ounce for ounce, bird brains are some of the most computationally dense organs in the animal kingdom. Calling someone a "bird brain" is honestly more of a compliment.

Ok so who's the smartest?

There's no definitive answer because different species dominate different areas. But after going through all of this, if you made me rank them, I'd probably go:

Evil genius tier: Corvids (crows, ravens, magpies, jays). The tool users. New Caledonian crows are probably the standout -- they craft hooks from sticks to pull grubs out of crevices, something we thought only primates could do. Ravens plan for the future. Magpies recognise themselves in mirrors. Jays hide food and then re-hide it if they think another bird was watching. That last one is wild -- it means they can model what another bird knows. They're paranoid in a way that requires theory of mind.

Con artist tier: Parrots (African greys, kea, cockatoos). The communicators and schemers. Alex the African grey is the poster child, but kea might be the most broadly impressive. A University of Auckland study found kea can judge statistical probabilities -- something previously demonstrated only in human infants and great apes. In other tests at Canterbury University, kea outscored gibbons. Actual primates. Goffin's cockatoos can unlock a sequence of five different locks in the right order to reach a reward. Each lock has a different mechanism. Worthwhile contenders for a spot in Ocean's Fourteen if they ever make one.

Quietly competent tier: Songbirds. Clark's nutcrackers, chickadees, and a handful of others. They won't pick your locks or craft tools, but they'll memorise 33,000 seed locations and find them nine months later under snow. The accountants of the bird world.

Honestly, corvids and parrots are neck and neck. Corvids edge ahead on tool use and physical problem solving. Parrots are ahead on communication and social cognition. Both would absolutely destroy your average pigeon in a pub quiz.

I also had to look up the dumbest bird. You might guess it's a turkey -- and they do have a reputation for being dim, mostly because domestic turkeys have been selectively bred to be so heavy they can't fly and so docile they just stand around. Wild turkeys are actually pretty sharp. But no, the real answer is the kakapo -- which is also a New Zealand parrot, funnily enough. The kakapo evolved with no natural predators, so when it encounters a threat it just... freezes. Stands completely still and hopes for the best. The males also have a mating call so confusing that the females often can't figure out where the sound is coming from. Between that and the freezing thing, there are fewer than 200 left. The kea got all the brains in the New Zealand parrot family.

What I took away from this

We default to thinking intelligence scales with brain size, that it's a mammal thing, that it correlates with being "higher" on some imaginary evolutionary ladder. Turns out it's about neuron density and architecture, not mass. A 10 gram raven brain running 1.2 billion neurons is doing more per gram than almost anything else in nature.

Anyway. Next time someone calls you a bird brain, just say thank you.