10 Most Intelligent Birds in the World

Ask most people to name an intelligent animal, and you'll hear chimpanzee, dolphin, or maybe an octopus. But birds seldom make the list. Some species can solve puzzles that would baffle a toddler, remember thousands of hiding places and even recognise themselves in a mirror. Here are the top 10 smartest birds in the world, ranked by problem-solving ability, memory, tool use and social learning.

Bird intelligence is not measured like a human IQ test. Instead, researchers look at a few particular behaviours:

• Tool use: Does a species make or use tools?
• Memory: How well does it remember locations months later?
• Planning: Can it plan for a future need?
• Social learning: How does it learn by watching other birds?

When a crow bends a wire into a hook to get to food, the bird is exhibiting the same type of flexible thinking shown by a two-year-old who uses a stool to reach a shelf.

The African grey parrot is the most cognitively advanced parrot known to science. The most famous example is Alex, a research subject studied for more than 30 years by comparative psychologist Irene Pepperberg. Alex learned to recognise colours, shapes and materials and could answer questions about quantity and difference, rather than just repeating sounds. That distinction is crucial: Alex wasn't copying; he was communicating.

In the wild, African Greys live in large, noisy flocks that wander through the rainforests of West and Central Africa, and that social complexity is likely part of the reason their brains evolved as they did. Monitoring the identities of individuals in a roving flock requires significant cognitive effort.

If there is one bird that has changed the way scientists think about bird brains, it is this one. New Caledonian crows not only use tools; they make them. They strip leaves from twigs to fashion hooks and shred pandanus leaves into barbed strips of a particular shape to extract grubs from tree bark. Some even carry a favourite tool from feeding site to feeding site instead of making a new one each time.

Laboratory studies have shown that these crows can solve multi-step puzzles, including puzzles that require them to use one tool to retrieve a second tool needed to access food. That's the kind of planning most animals don't display.

Ravens are corvids too, perhaps even smarter than their crow cousins. They remember where they hid food and which places rival ravens watched, and they will return later to move food that was seen. That's a kind of deception planning researchers once thought only primates could do.

Ravens play too. Young ravens slide down snowbanks, toss sticks to each other in mid-air, and hang upside down from branches with no apparent purpose other than the fun of it. This kind of playful behaviour is often a sign of a brain built for flexible learning rather than pure instinct.

The alpine parrot of New Zealand is famous for two things: curiosity and mischief. There are reports of keas opening zippers, unscrewing bolts on parked cars and working together to raise the lid of a dustbin. In experiments, keas learnt to use tools to obtain food behind a barrier more quickly than most other bird species tested.

What sets the kea apart is their willingness to experiment. Unlike many animals, they tend to investigate unfamiliar objects rather than avoid them. This unique trait enables them to excel at problem-solving, which is why hikers in New Zealand are advised to monitor their gear closely.

Goffin's cockatoos don't use tools in the wild, but put one in front of a locked box with food in it, and see what happens. In Vienna, researchers studied a cockatoo named Figaro, who spontaneously made a tool out of a piece of wood to rake food closer, something that had not been trained. Since then, Goffin's cockatoos have been able to work through five-step mechanical puzzles in sequence, remembering which lock had to be undone before the next would open.

They also learn by watching each other, meaning a discovery made by one bird can spread through a group in a matter of days.

The magpie made its mark in cognitive science history in 2008, when researchers placed a small, coloured sticker on the birds in a location visible only in a mirror. Some of the birds tried to remove the sticker when they saw their reflection, a reaction known as passing the mirror self-recognition test, previously documented mainly in great apes, dolphins and elephants.

Like their relatives, the corvids, magpies also cache food, and they adjust their hiding strategy when another magpie observes them.

Pigeons are dismissed as background city wildlife, but their cognitive skills are well documented. Pigeons can identify all 26 letters of the English alphabet, identify themselves in photographs taken years apart, and distinguish a Monet from a Picasso painting at levels well above chance — an insight from experiments on visual category learning.

Even more impressive are their navigational skills: homing pigeons can locate their way back to a loft from hundreds of miles away, using a mix of sensing the magnetic field, the position of the sun and visual landmarks.

Jays are members of the corvid family, and they have a rare skill even for clever animals: they seem to contemplate what other jays are thinking. In experiments, jays that had stolen food from other birds in the past hid their caches more carefully when watched – as if they expected a watching bird to steal from them in the same way. That's a very basic form of perspective-taking, and it is not something most animals do.

The yellow-naped and blue-fronted Amazon parrots are great vocal learners and problem solvers and are commonly kept as pets in the US. They learn words in context, not just through pure repetition, and many owners report their parrots using a learned phrase at an opportune moment – asking for a specific food by name, for instance, not just when prompted.

This is also why they need heavy mental stimulation in captivity; a bored Amazon parrot is a destructive one.

Hooded crows, native to parts of Europe and the Middle East, have been filmed dropping walnuts onto busy roads and waiting for passing cars to crack the shells before collecting the exposed nut once traffic clears. You can even see them timing the drop to red lights so they can walk out and safely pick the nut without having to dodge traffic.

It's one of the clearest examples in the wild of a bird using an external, human-made system to solve a problem about food.

Two factors keep popping up on this list: the complex social lives of corvids and parrots and the need for flexible foraging. Corvids and parrots are both social animals that benefit from keeping track of faces, relationships, and sometimes outsmarting rivals. Add a food source that isn't just lying around in the open — grubs under bark or nuts inside shells — and you get selective pressure for the kind of flexible problem-solving you see on this list.

It also helps to have a high density of neurones in the pallium, the bird brain's equivalent of a cortex, compressed into a much smaller space than a mammal brain. Size is not the story; density is.

Bird intelligence isn't like human intelligence, and that's why it's worth paying attention to. A crow bending a wire into a hook and a raven plotting to hide food from a rival are both solving real problems with tools that evolution never gave them directly: a beak and a reliable memory. So the next time a crow looks a little too intently at you from a fence, you might want to give it some respect.