NEW HAVEN, Conn. (WTNH) — The Connecticut Audubon Society issued another “high” lights out alert on Thursday as more songbirds continue to migrate across New England.

With 3 million songbirds flying across the state on Friday, 500,000 again earlier this week and an estimated 557,700 overnight on Thursday, the society stressed the need to turn off lights so that the birds don’t become confused.

The group has placed the entire state in the “high” category, estimating that 2,300 birds will fly over Hartford, 1,900 over New Haven and 1,600 over Bridgeport on Thursday.

Light pollution can dim the stars, confusing birds. The birds can then fly into buildings or circle until they collapse from exhaustion.

The weather can impact migration forecasts, according to Ken Elkins, the director of Connecticut Audubon’s Coastal Center at Milford Point.

“Low cloud cover and fog would increase our chances of birds landing here, especially near the coast,” he said in the society’s announcement.