History Channel - Original Air Date: 2007-8
Another good entry in the Monster Quest series, this examines stories of giant birds in the US from the pioneer days to the present. Fossil records show that ancient birds were perhaps twice the size of today's largest raptors. Pterosaurs grew even larger. There is no evidence, though, of such birds -- or dinosaurs -- surviving into the modern era. There are, however eyewitness accounts. And there is at least one tantalizing film. Experts dispute whether the film shows a known animal (turkey vulture) or something much larger. One of the most valuable aspects of this show is its study of how people perceive objects in the sky--often believing flying objects to be much larger than they actually are. This is demonstrated with a large bird kite (24 foot wingspan - flown at 300 feet), which witnesses are unable to accurately estimate the size of (most think it's much larger than it actually is). Even pilots, the show implies, can make such mistakes. The sky just doesn't have proper references to judge sizes. (This same problem applies to UFO sightings.) Some African eagles are known to prey on primates (monkeys), and experts speculate that a fear of large birds may be hard-wired into human evolution. It seems unlikely that a huge unknown bird is alive today, but people are still seeing something.