In a development that will surprise absolutely no one who has ever been stared down by a crow, researchers at the University of Tübingen have found that the birds can evaluate visual information roughly twice as fast as mammals - and they do it with a brain that isn't even built the same way.
Much of what we know about decision-making comes from monkeys watching dots. In the classic random-dot-motion task, a cloud of flickering specks drifts weakly in one direction while the subject tries to determine whether - and in which direction - it's moving. In the primate neocortex, neurons gather visual evidence over time, their firing rates climbing until they cross a threshold, at which point the animal commits to a decision. Avian brains, however, lack a neocortex entirely, so it wasn't obvious how birds pulled off the same trick.
"This was the big question," said Andreas Nieder, a neurobiologist at the University of Tübingen. "How [would] a differently organized avian brain encode decisions?"
To find out, Nieder and colleague Philipp Schmidbauer put two hand-raised carrion crows through the same task the monkeys faced, recording brain activity along the way. The crows solved it using the same mathematical logic as primates - despite a radically different brain structure - and did it two times faster. The birds pecked at targets flanking a touch-sensitive monitor displaying white dots on black, with some fraction drifting coherently left, right, up, or down. Correct answers earned a mealworm, which is presumably the avian equivalent of a gold star.
"We intentionally wanted to have exactly the same random-dot motion task," Nieder said. "The only difference was that the crows had to peck to indicate their decision, whereas monkeys were indicating by making an eye movement."
The researchers varied the coherence of the dots from 81 percent - trivially easy - down to 3 percent, which is barely distinguishable from noise. They also included a zero percent condition with no correct answer. Both birds scored better than chance even at 3 percent coherence.
While the crows worked, the team recorded from 248 neurons in the nidopallium caudolaterale (NCL), a region at the top of the avian processing hierarchy widely regarded as the functional counterpart of the primate prefrontal cortex - despite being built on entirely different lines. Birds and mammals parted evolutionary ways more than 360 million years ago. The mammalian cortex is arranged as stacked sheets of cells; the equivalent avian tissue is organized into dense clusters with no layering at all. That alternative architecture, the study found, proved faster.
Measured from the moment the dots appeared to the moment the bird's head started turning to peck, the crows averaged 235 milliseconds. In closely matched versions of the task, monkeys took roughly 410, 490, and 600 milliseconds across three studies. The obvious question was whether the birds sacrificed accuracy for speed. They did not. Crows performed as well as monkeys or humans on the same task.
"We've never forced the crows to be as quick as possible," Nieder explained. "We just gave them a self-paced decision. And even in this situation, they were twice as fast compared to any monkey or human that I'm aware of."
One possible explanation was that avian brains operate on a fixed deadline, and the data initially seemed to support that: reaction times ran from 220 milliseconds at the easiest task to just 254 at the hardest, a difference of only 34 milliseconds. But Nieder doesn't think the avian brain is simply wired to produce answers on a timer. "If you zoom in, there is a statistical increase in the reaction time when the coherence is going down," he said. "They show the same effect as mammals. It's just much less pronounced, because everything happens much faster."
There are no shortcuts, he explained - the crows had to look at the direction of the dots and process that information, with no other cues available. "That's why I think they do accumulate evidence. They have to," Nieder said. The neuronal recordings back this up: 58 of the 248 sampled neurons fired differently depending on which direction the bird would eventually choose, and they began registering that decision about 70 milliseconds after the dots appeared - roughly 170 milliseconds before the bird's head moved. "The neurons were accumulating sensory evidence, which is very reminiscent of what monkey neurons would do in the neocortex," Nieder said.
That signal is known as a decision variable, a running tally of evidence climbing toward a commitment. "It turns out that what we find in the crow brain looks basically the same," Nieder said. "And that's interesting considering their brains have evolved very distinctly, as if evolution has found the same physiological mechanism twice, independently."
So far, the team can't pin the crows' speed on any single fast process. Nieder's leading explanation is that nearly every biological process runs faster in birds than in mammals - a cascade beginning with vision (avian visual systems are exquisitely movement-sensitive), continuing through the decision itself, and extending to the motor response. Two physiological factors likely make this possible. The first is size: flight imposes strict weight limits, so birds pack enormous numbers of very small neurons into very small brains, with shorter axons. "Long lines take time. Short lines speed everything up," Nieder said. The second is temperature: humans run at about 36.6° Celsius, while birds go up to 41 or even 42°, speeding up all chemical processes. "Every ion channel would open and close faster. Every transmitter would move through the synaptic cleft faster," Nieder explained. "Evolution really took their bodies to the limit. This is life in the fast lane, not only in the brain, but also respiration, the cardiovascular system - everything is going toward the limit in birds."
There are caveats. The study included only two birds - a small sample, though Nieder notes that monkey studies of comparable complexity typically use the same number. The 235-millisecond figure for crows and 400-plus for primates are not absolute limits; they apply specifically to the random-dot-motion task, which inherently requires waiting to see which way things drift. And it may be hard to learn whether the results extend beyond corvids. "The problem with many other birds is that they are not as smart as corvids and crows and you need a smart bird in order to train it to do exactly this task," Nieder said. So it remains unclear whether the crows' excellent decision-making stems from avian brains being speedy in general or from crows simply being smarter than other birds. "Among birds, the corvids are renowned to be extremely intelligent, so maybe there's something special about them," Nieder said.
The study is published in Science, 2026. DOI: 10.1126/science.aed6459.