Reunion Tower, the little ball on the Western edge of downtown Dallas, is famous for its sassy light shows illuminating the Dallas skyline. But in recent years, the building has followed a bird-friendly policy of dimming its lights, and that dimming is about to get underway.

From October 1 through October 21, Reunion Tower will observe the following lighting schedule:

• Sundown to 11 pm: lower its lights
• 11 pm-6 am: go completely dark
• 6 am-sunrise back to dim

The building enacts these changes to protect birds that are migrating through Texas.

Dallas is on the path of the Central Migratory Flyway, which extends from the Northwest and heads diagonally southeast through Mexico.

Every fall and spring, nearly two billion birds travel through Texas. The bird migration is one of the largest on the planet, and takes place at night. Light attracts migrating birds, making them vulnerable to collisions with buildings and causing them to become disoriented and distracted.

Birds get pulled into urban areas, collide into buildings, and die. Volunteer surveys - in which people go out and count actual dead bodies - in cities such as Dallas, Austin, Houston, and Fort Worth, finds hundreds of dead birds every night. It adds up to nearly a billion birds killed in the U.S. each year.

Dallas-Fort Worth is the third most dangerous area in the U.S. for migratory birds to travel through; Chicago is No. 1, followed by Houston which is No. 2.

As this map from the National Oceanic and Atmospheric Administration shows, Dallas and Houston are both massively lit, representing major obstacles to the success and survival of the birds' migration.

Lights Out Texas was initiated as a statewide effort in Spring 2020 to protect birds from light pollution by the Cornell Lab of Ornithology and BirdCast, with the essential support of founding Texas partners Houston Audubon, the Dallas Zoo, and the Perot Museum of Nature and Science.

According to Audubon, the actual critical migration period through Dallas is September 6 through October 29. A glittery skyline is surely pretty, but downtown should just shut it down during those times.