Junco beaks lengthened during pandemic campus closures, then reversed, showing rapid evolution from human-driven changes.

During the pandemic, dark-eyed junco songbirds at UCLA developed longer beaks, likely due to changes in food availability when campus activity dropped. Researchers suggest this shift, reversing after students returned, may reflect rapid evolution driven by environmental changes. The findings, published in PNAS, show wildlife can adapt quickly to human-driven disruptions, offering insight into real-time evolutionary processes.