Cornell BirdCast Data Reveals Massive Nighttime Bird Migration

Millions of birds travel north under cover of darkness each spring, experts say.

Apr. 17, 2026 at 8:51pm

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A highly textured, abstract painting in earthy tones of green, blue, and ochre, featuring sweeping geometric arcs, concentric circles, and precise botanical spirals against a deep indigo background, conceptually representing the complex patterns and intersecting flight paths of migrating birds across the night sky.Cornell University's BirdCast data reveals the staggering scale of nocturnal bird migration, with millions of winged travelers traversing the skies each spring.Buffalo Today

According to data from Cornell University's BirdCast project, millions of birds are quietly migrating north at night as spring migration ramps up across the United States. Researchers say nearly 80% of bird species travel under the cover of darkness, with some counties seeing over 1 million birds passing overhead in a single night.

Why it matters

Understanding the scale and timing of these massive nighttime bird migrations is crucial for conservation efforts, as well as raising public awareness about the incredible natural phenomenon happening overhead while most people sleep.

The details

The BirdCast data shows that overnight bird movement is already underway at low to medium levels across Western New York, with the number of birds traveling north expected to increase as the spring season progresses. Dr. Adriaan Dokter, a research associate at Cornell, noted that just last Sunday, over 1.2 million birds were recorded flying over Erie County in a single night.

  • Spring migration season is currently underway.
  • Overnight bird movement is expected to continue at low to medium levels across the region.

The players

Cornell University BirdCast

A research project that tracks and analyzes bird migration data across the United States.

Dr. Adriaan Dokter

A research associate at Cornell University who studies large-scale bird migration patterns.

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What they’re saying

“In Erie County, for example, only last Sunday I saw there were like 1.2 million birds flying over that little county only in a single night, so it's a massive phenomenon, which we think people should know about.”

— Dr. Adriaan Dokter, Research Associate, Cornell University

The takeaway

The sheer scale of these nighttime bird migrations highlights the incredible natural wonders happening above us, even as most people sleep. Raising awareness of this phenomenon can help drive conservation efforts and inspire people to appreciate the natural world around them.