Wisconsin experiences massive bird migration waves

Millions of birds are currently undergoing fall migration over Wisconsin, with peak periods occurring throughout September. Scientists from BirdCast and Purdue AeroEco Lab estimated that 98 million birds passed over the state on the night of September 9, followed by another 84 million on September 12.

To mitigate the risk of deadly window collisions—which affect an estimated 3.5 billion birds annually in the United States—experts recommend turning off unnecessary outdoor lights between 11 p.m. and 6 a.m. Artificial light can disorient nocturnal songbirds, drawing them toward urban buildings. BirdCast issues ‘Lights Out Alerts’ during the top 10% of migration nights to notify the public of high bird traffic.