Nearly all Native American tribes tell recount stories of the Thunderbirds. These were thought to be enormous birds, similar to vultures or eagles, and were said to cause the thunder during storms and could carry full grown men away to their roosts. It was believed that these stories were merely part of the culture, but fossilized evidence has been found in parts of Argentina, of a large bird similar to a modern sea gull. Ironically, throughout the years, stories have continued to surface of extremely large birds flying through the skies of North America. Scientists believe that these sightings are nothing more than large eagles or even California Condors. Eye witnesses say that what they saw was bigger than any condor on record.