How the Pandemic Lockdowns Changed a Songbird’s Beak

New York Times - WorldCenter-LeftEN 4 min read 100% complete by Emily AnthesDecember 15, 2025 at 09:00 PM

AI Summary

long article 4 min

A study published in PNAS in December 2025 found that the beak shape of urban dark-eyed juncos in Los Angeles temporarily reverted to a more wildland-like form during the COVID-19 pandemic lockdowns. These juncos, originally forest-dwelling sparrows, had adapted to urban life at UCLA over two decades, developing shorter, stubbier beaks likely due to a diet of human food. When the campus shut down, the next generation of birds exhibited beak shapes closer to their forest counterparts. After restrictions lifted, the urban beak shape returned, demonstrating the rapid and significant impact of human activity on animal evolution. Researchers at UCLA conducted the study, highlighting the profound influence humans have on shaping the physical traits of wild animal populations.

Key Entities & Roles

Key Player Opposition Context

Los Angeles ×270% Pamela Yeh 80% University of California, Los Angeles ×2100%

Keywords

dark-eyed juncos 100% beak shape 90% pandemic lockdowns 90% urban adaptation 80% natural experiment 70% wild animals 60% evolutionary biology 60% diet change 50% u.c.l.a. 50% anthropause 40%