Here's why Reunion Tower's lights will be off tonight

Reunion Tower in Downtown Dallas will go dark overnight starting on Thursday.

Reunion is participating in an initiative with the Texas Conservation Alliance to help protect migrating birds.

From April 11 to May 12, the lights on the famous tower will be at 50% output from dusk until 11 p.m., completely dark from 11 p.m. to 6 a.m. and back to half power from 6 a.m. until sunrise.

The Texas Conservation Alliance says that during the Spring months many bird species return to the U.S. after spending the winter in Mexico and South America and hundreds of millions of birds fly through Texas.

DALLAS - JANUARY 12: The Hyatt Regency Hotel and Reunion Tower at sunset on January 12, 2009 in Dallas, Texas. (Photo by Ronald Martinez/Getty Images)

Birds use the moon and stars to navigate and lights from buildings can attract and disorient them.

Dallas is the third most dangerous city in the U.S. for birds, according to the Texas Conservation Alliance, behind only Chicago and Houston.