More than 5 million birds crossed over Wake County in a single night this month, according to radar-based estimates, part of a wildlife spectacle unfolding overhead as a global report finds nearly half the world’s migratory bird species are losing ground. BirdCast estimated about 5.2 million birds over the county on one recent night, compared with roughly 2.2 million the night before — a sharp swing that reflects changing migration conditions rather than a fixed nightly count.
Those figures come from BirdCast, a project that uses weather radar to detect and predict the numbers and flight directions of migrating birds aloft, according to WRAL. The night-to-night swing from 2.2 million to 5.2 million birds illustrates a point migration trackers make often: the numbers can change dramatically depending on weather. BirdCast notes that more than 80% of migratory bird species in North America migrate at night, using weather radar to catch movements that are otherwise invisible to the naked eye.
September is a busy month for migration in North Carolina, with peak activity generally running from mid-September into early October, though some species keep moving through October and November. Many of the birds passing overhead are nocturnal migrants that fly for several nights before stopping to rest and refuel. They typically take off about an hour after sunset and may travel 100 miles or more before descending to find food and shelter, and many return to the same stopover sites year after year.
A Global Decline Playing Out Overhead
The scale of the nightly flights over Wake County arrives alongside sobering findings from BirdLife International’s 2026 State of the World’s Birds report, which found that 45% of migratory bird species worldwide have declining populations and 11% are threatened with extinction, per WRAL’s reporting. A separate account of the same report, published by artensterben.de, put the number of species studied at 1,843 and found 30% are considered stable while only 14% are increasing; data were insufficient to classify the remaining 11%. That same account reported that 200 species, or 11% of the total, are considered globally threatened, and that shorebirds are faring especially poorly, with 54% of migratory shorebird species showing declining trends worldwide.
What the 5.2 Million Estimate Means
The BirdCast figure is an estimate of movement overhead, not a count of birds on the ground. According to BirdCast, its migration forecasts measure the intensity of birds in active flight. Its dashboard’s nightly counter estimates the total number of birds that have overflown a selected area since the start of the night, so the birds counted over Wake County did not necessarily land there, according to BirdCast. BirdCast says its dashboard can compare a selected night’s traffic with historical patterns from 2013 to 2021. Those comparisons provide a way to place the Wake County total in a longer record rather than relying on the largest night alone.
The report attributes the declines to a mix of pressures: habitat loss, intensive agriculture, unsustainable hunting, pollution, invasive species, and a warming climate. Researchers have also observed some species returning earlier during spring migration, a shift that a warming climate can drive by disrupting migration timing and potentially creating a mismatch with the insects and plants those birds rely on for food once they arrive.
Local Habitat Loss Adds Up, Bird Experts Say
Locally, the pressure shows up one lost woodlot at a time. Phil Doerr, who works with the Wake Audubon Society’s Lights Out program, described the overnight flights as “this absolutely amazing wildlife spectacle that’s going on all around us, above us every night,” according to WRAL. But Doerr also pointed to the flip side of that spectacle: when a wooded lot disappears to development, he said, “there’s another woodlot gone,” meaning one less patch of habitat for birds that depend on it.
John Gerwin told the outlet that continued habitat change leaves birds with fewer options: “As we change the habitat more and more, it’s less habitat for some of these birds.” The need for connected stopover habitat can extend across a migration route. One study tracked warblers from wintering grounds on Central American coffee farms to breeding grounds in Wisconsin and Minnesota, while a Louisiana waterthrush was recaptured at the same small stream on a coffee farm over several years.
Why Lights Matter So Much at Night
Artificial light poses a particular hazard for birds moving after dark. It can attract and disorient nocturnally migrating birds, drawing them toward developed areas where they may become exhausted or collide with windows, WRAL reports. Gerwin put it plainly: artificial light is like a beacon attracting birds for the wrong reason. Windows themselves pose a hazard to migrating birds, and window treatments can help make glass more visible so birds don’t mistake it for open sky.
To address that, Wake Audubon has worked with the City of Raleigh to reduce unnecessary building lighting during migration periods. Homeowners can take similar steps at a smaller scale, including turning off unnecessary lights, aiming outdoor lights downward, and using motion sensors instead of lights left on all night. Native plants and shrubs can also help by providing food and shelter for exhausted birds stopping to refuel mid-journey.
The push to dim the skies during migration isn’t unique to Wake County. BirdCast announced a system in February that uses its migration-forecast data to enable real-time lighting adjustments during peak migration events, aiming to cut down on the number of birds that collide with buildings. The same organization recorded an extraordinary night of its own about four and a half months earlier, when nearly 860 million birds migrated across the night of May 3-4, a total BirdCast called unusual for spring and a record for the largest spring migration night it had analyzed to that point.
