Some species, including northern cardinals, northern mockingbirds, killdeers, Australian magpie-larks, and American robins, showed longer daylight extensions than average.

A new global study analyzes millions of bird calls to assess how artificial light pollution reshapes birds’ daily activity, revealing longer wakeful periods in brighter environments.

In areas with higher artificial light, birds begin vocalizing about 18 minutes earlier and end about 32 minutes later, extending their day by roughly 18 minutes in the morning and 32 minutes in the evening.

The study represents a global citizen-science effort to quantify how light pollution reshapes avian behavior.

Researchers used citizen-science data from BirdWeather alongside satellite-measured light pollution to draw global conclusions, though the study region is biased toward the United States, Australia, and western Europe.

Independent experts described the data as impressive and unprecedented in leveraging citizen science, while acknowledging regional biases in the dataset.

The findings are highlighted in Nature-related coverage as of late August 2025, underscoring the study’s significance in the field.

Big-eyed birds were found to be more sensitive to light pollution, with effects amplified during the breeding season, while nesting in opaque cavities appeared less affected.

Overall, bright city lights contribute to about 50 extra minutes of daily activity for birds, combining earlier singing and later quit times.

While the sleep and energy-budget implications are not fully determined, longer awake periods could influence breeding and feeding, and humans and birds may respond differently to light.