Birds are cleverer than many animals. Scientists identify a key clue about why birds have better problem-solving skills

Birds are often associated with intelligence, from crows using tools to parrots learning complex behaviours. But what actually makes some birds better problem-solvers than others? Scientists have now put several bird species through a series of cognitive tests to find out. The findings reveal that one particular mental ability appears to be closely linked to both larger brains and a greater tendency to invent new ways of finding food in the wild.

A new study involving 203 birds from 15 passerine species offers an intriguing answer. Researchers found that birds that performed better at laboratory problem-solving tasks were also more likely to show technical innovation in the wild and had larger brains. Interestingly, other abilities often linked to intelligence, such as self-control and learning new rules, did not show the same connection. The findings offer a fascinating clue to avian intelligence.

Birds that solve puzzles better may be more innovative

The study, published in Nature Ecology & Evolution, examined whether different types of cognitive skills could explain why some bird species are more innovative in the wild. Researchers tested birds on several tasks designed to measure different mental abilities. These included solving physical puzzles to reach food, controlling impulsive behaviour, learning which colours were linked to rewards and adapting when those rules changed.


The most striking result came from the problem-solving tests. Birds that were faster at completing extractive-foraging puzzles belonged to species with higher rates of technical innovation in the wild. In simple terms, the birds that were better at figuring out how to physically get food in the laboratory were also the ones whose species were more likely to invent new ways of finding food in nature.

What did the bird intelligence experiment involve?

The researchers tested four major areas of cognition.

Problem-solving: Birds had to remove obstacles to reach food using different physical techniques, including pulling, knocking, flipping, grabbing, piercing, tearing and dragging.

Self-control: Birds had to resist pecking directly at visible food behind a transparent barrier and instead find a way around it.

Associative learning: Birds learned to connect a particular colour with a food reward.

Reversal learning: Researchers then changed the rule by switching the rewarded colour, testing how quickly the birds could adapt. The researchers also recorded traits such as shyness and neophobia, or fear of unfamiliar objects.

Bigger brains were linked to better problem-solving

One of the most interesting findings was the connection between problem-solving ability and brain size. Bird species that performed better on the puzzle-solving tasks tended to have both larger absolute brains and larger brains relative to their body size.

That gives scientists an important clue about why some birds appear particularly capable of tackling unfamiliar challenges. Their ability to develop new physical solutions was associated with brain structure as well as innovation in the wild.

Not every form of intelligence worked the same way

The study also challenged the idea that behavioural flexibility is simply one broad ability. Researchers found that self-control, associative learning and reversal learning did not predict problem-solving performance, technical innovation in the wild or brain size.

The only clear relationship among the learning tasks was between associative learning and reversal learning. This suggests that being good at one type of mental task does not necessarily mean a bird will be good at every other task associated with intelligence. The researchers therefore argue that problem-solving may be a particularly useful experimental measure of innovation, while other abilities may represent different cognitive skills.

Why technical innovation matters

Scientists have long observed that some animals are better than others at coming up with new ways to deal with challenges. These innovations can include discovering new ways to obtain food or using unfamiliar techniques to overcome obstacles. Previous research has linked innovation with factors including survival, colonising new environments, brain size and the number of neurons in parts of the brain.

What the study reveals about clever birds

The researchers used large datasets covering field observations, brain measurements and laboratory experiments. Their analysis also accounted for factors such as species relatedness, personality, testing conditions and diet.

The results point to a fairly specific explanation for innovation amongst birds: the ability to invent new physical solutions appears to matter more than simply having strong self-control or being good at learning changed cues.

So, the next time a bird figures out how to reach food, open something or overcome an obstacle, it may not just be displaying persistence. Its ability to solve a brand-new physical problem could be one of the clearest signs of the kind of intelligence that helps some bird species innovate in the wild.