Crows can evaluate visual info twice as fast as mammals

Researchers tested two hand-raised carrion crows on a visual motion task commonly used to study decision-making in monkeys. The birds watched dots moving in different directions, with varying proportions moving coherently, then pecked a target to identify the overall direction. They performed above chance even when only 3 percent of the dots moved together. While they worked, researchers recorded activity from 248 neurons in the crows’ nidopallium caudolaterale, a brain region considered functionally comparable to the primate prefrontal cortex. The crows took an average of 235 milliseconds to respond, compared with roughly 410-600 milliseconds in comparable monkey studies, without sacrificing accuracy.

Neural recordings suggest the birds reach decisions through the same basic process seen in mammals: neurons accumulate sensory evidence into a running signal that guides a choice. Direction-related activity appeared about 70 milliseconds after the dots appeared and well before the crows began moving to peck. The finding is striking because bird brains have a different, non-layered organization from mammalian cortex, yet appear to use similar decision-making logic. Researchers suspect birds’ speed reflects several factors, including compact brains with shorter neural connections and higher body temperatures that accelerate biological processes. The results are limited by the two-bird sample and by the particular task; it remains unclear whether the speed is common across birds or especially pronounced in intelligent corvids.