The birds are on the move.
In flocks so think they look like a “storm” cluster on your weather radar, the birds are moving for their annual fall migration.
Most of the migration is concentrated in the central U.S., with Ohio being one of the main hot spots. Radar estimates suggest more than 1.2 billion birds took to the skies Sept. 25 — the largest surge of the season — flying around 2,000 feet above the ground at roughly 22 mph, according to meteorologist Ross Ellet at WTVG in Toledo, Ohio.
“We said BILLION once before in BirdCast history, on 6 October 2023! Amazing! Welcome back to the billion bird night club!” BirdCast, which tracks bird migration, wrote online. “There is only one thing more to say beyond here is your second billion bird night. What is that you may ask? It is important! This epic night did not stop at a billion: no, it grew beyond that, and beyond 1.1 billion, and even beyond 1.2 billion, becoming the biggest night of migration yet recorded by BirdCast!”
Why birds are migrating in Rhode Island?
In Rhode Island, the bird migration isn’t as dense. BirdCast estimated that 16,000 birds flew over the Ocean State on Sept. 25, compared to 26,000 in Ohio.
The historic peak of migration in Rhode Island is in early November.
This time of year marks the peak of fall migration. Millions of birds are leaving northern breeding grounds for warmer southern wintering areas, following seasonal changes in daylight and prevailing winds that help them navigate while conserving energy, according to the National Audubon Society.
Timing is crucial. As temperatures drop, plants begin to die back, reducing the availability of insects, seeds and other food sources. By moving south, birds gain access to abundant food and suitable habitats, ensuring they survive the winter and return north ready to breed in spring. New seasonal ranges provide better temperatures, more resources and opportunities to produce healthy offspring.
“Among the gold medal winners of migrating birds is the Arctic Tern. Taking part in the longest migration known in the animal kingdom, this tern travels 55,923 miles every year, literally from pole to pole!” Audubon Rockies Director of Policy and Outreach Daly Edmunds wrote online.
In Rhode Island, right now BirdCast shows Blackpoll Warblers, White-eyed Vireos, Ruby-crowned Kinglet, American Redstart and more are among the nocturnal migrants.
More: Climate change leaves some migrating birds ‘out of sync’ and hungry
Why does the radar pick up birds?
It’s not just birds — radar can also pick up bats and swarms of insects.
Weather radar sends out pulses of radio waves and detects what bounces back. Large flocks of birds — or swarms of bats or insects — at the right altitude and speed reflect enough energy to appear on radar much like a storm.
Birds usually don’t show up on radar, but during fall migration, huge numbers fly at altitudes within the radar beam, typically 1,000–3,000 feet at night. Observers can distinguish birds from other signals by timing and speed. Most migrating birds depart in the evening, fly through the night, and land by sunrise. They also move faster than the prevailing winds, according to Smithsonian Magazine.
“Using the velocity image, though, you can get an idea of how much non-bird noise you’re seeing on the reflectivity image,” David A. La Puma, the director of the Cape May Bird Observatory, told the magazine in 2014. “Birds tend to migrate 15-20 kts [knots] faster than the prevailing wind (given the wind is a tailwind), so by checking the winds at 950mb (2500 feet, roughly), you can determine the wind speed, compare it to the speed at which the objects are moving across the radar, and therefore rule out any object traveling too slow to be birds.”
More than 1.2 billion birds were caught on the radar on Thursday, Sept. 25, 2025, in peak fall migration.
Observers can even distinguish birds from other species like insects, which travel much slower, and typically, with the speed of the winds.
In the weeks before migration, many species gather at communal roosts. When they take off, radar often detects “roost rings” — expanding, doughnut-shaped patterns formed as birds leave in all directions. Some species return to the same roosts nightly, often near water, so these rings can appear repeatedly, unlike storms, which take varied shapes.
“As they travel further from their roosting site and reach higher altitudes, they are detected by radar until they either rise above or drop below the radar beam,” according to the National Weather Service office in Green Bay.
Are the birds visible in person if they’re radar detected?
Because these radars typically detect birds at night, flying between the height of a 100-story skyscraper and half a mile up, it’s unlikely you would see these giant flocks from the ground.
Why do birds migrate at night?
Many bird species migrate at night to avoid predators, conserve energy, and take advantage of calmer winds. Cooler nighttime temperatures reduce the risk of overheating, and flying under the cover of darkness makes it harder for predators like hawks to spot them. Nighttime navigation is also aided by stars, the moon and the Earth’s magnetic field, which help birds stay on course over long distances, according to Audubon Magazine.
How to help during bird migration
Migrating birds face hazards including limited food, habitat loss, and artificial lights. You can support them by:
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Reducing light pollution: Turn off unnecessary outdoor lights at night to prevent disorientation.
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Keeping cats indoors: Domestic cats pose a significant threat to migrating birds.
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Providing food and water: Offer native seeds, fruit, and clean water to fuel their long journeys.
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Creating habitat: Plant native trees and shrubs to provide resting and feeding areas.
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Preventing window collisions: Use decals or screens to make windows visible and reduce bird strikes.
Brandi D. Addison covers weather across the United States as the Weather Connect Reporter for the USA TODAY Network. She can be reached at [email protected].
This article originally appeared on The Providence Journal: Bird watchers check the weather radar. 1.2 billion birds are migrating
