The Comanche tribe call it ba'a' and the Potawatomi use the name chequah, but most people know of this mystery animal as Thunderbird. Although gigantic birds are reported in the past and present from various areas of the globe, the Thunderbird is isolated to North America. Native Americans believed that these giant birds brought thunder and rain with them as they flew through the air by flapping their wings, and lightning by closing their eyes. Nevertheless, the distinction between the stories of the Native Americans and people of today are not too far apart. Modern reports of Thunderbirds arise from various locations in North America, with a large occurrence from Pennsylvania to the Central states.
Wingspan estimates are necessarily all guesswork.
But observers sometimes have had the benefit of a measurable object for comparison or the benefit of time to observe a resting bird. The results most often provide sizes of 15 to 20 feet. The bird at rest or on the ground appears to be four to eight feet tall. Remarkably, a bird of 15 feet in size would be the largest bird known in the world today. These are all truly marvelous birds and respectable in their majesty.