A “dirty bird” is a reference to the infamous canaries in the coal mine, birds sent down as early indicators to determine whether deadly gases were present. It’s part of the heritage of coal mining: the bird lives and the mine is safe; the bird dies and it is not. As team president Chuck Domino outlined in a video announcing the change:
“In the early 1900s, canaries were employed in West Virginia coal mines to detect methane gas to determine whether or not it was safe for coal miners to proceed. These canaries risked their lives for the coal mining industry in West Virginia. It was a dirty job, but these birds were up to the task. Ladies and gentlemen, on this day in the state capital of Charleston, West Virginia, we proudly honor these great little creatures who played such an important role in West Virginia’s coal mining industry. Some sacrificed their lives. These birds emerged from the mines weary and covered in coal dust to signal to the coal miners that it was safe to proceed. And now, here they are fans, representing West Virginia’s coal mining heroes, your professional baseball team, your Charleston Dirty Birds!”
The team will still play Tuesdays and Saturdays as the Charleston Charlies.