Pandemic-era beaks: UCLA juncos show rapid, reversible evolution
UCLA researchers found dark-eyed junco songbirds on campus hatched in 2021–2022 developed longer beaks, resembling mountain birds, likely in response to a more limited, campus-based diet during Covid-19 closures. After restrictions eased and students returned, birds hatched in 2023–2024 showed shorter beaks again, suggesting a rapid, reversible evolutionary pulse tied to human activity. The team is pursuing genetic data to confirm if these shape changes are genetic, and highlights how quickly wildlife can adapt to urban environments.