Meet the Thunderbird

One of the less well-known North American cryptids is the thunderbird, described as a bird larger than any currently known species strong enough to lift and possibly carry off a small child. Stories about thunderbirds attempting to lift children are generally regarded as tall tales, since as far as anyone knows none of these reported attempts have ever been successful and it's hard to imagine a known species of bird could be such a powerful flyer. Birds are built light, which is why they can fly in the first place.

Skeptics generally brush off reports of attempted abductions and note that it is easy to mistake the size of a flying bird in the air. They suggest that thunderbird sightings are simply sightings of large known raptor species that for whatever reason, possibly optical illusions, appear to be larger than their actual size. North America is home to a number of such large species such as several varieties of eagles and condors. In this case, it appears that the skeptics are right.

This video shows an actual "thunderbird attack" captured in Montreal that conforms to most reports, in which a large bird successfully lifts but is unable to carry off a child. Furthermore, the responsible bird can clearly be identified - it's a golden eagle, a common large North American raptor. While it seems remarkable that a bird weighing perhaps ten pounds could possibly be strong enough to lift a child, here it is. Golden eagles grow larger than the bird shown here as well, with potential wingspans of more than seven and a half feet.

The ability to lift prey heavier than their own body weight is a huge evolutionary advantage for eagles. Their normal hunting tactics consist of surveying prey from the air and then swooping down to grab it with their powerful talons. While a human child is larger than the bird's usual prey, clearly they're not above making an occasional attempt if the opportunity presents itself. So this is a classic case of a cryptid legend springing from the actions of a real animal - and a well-recognized one at that.

UPDATE: So it turns out that video is a fake, created by an animation studio in Montreal that has now taken credit for it. Still, I remain convinced that eagles are the best explanation for the stories behind thunderbird attacks, and that the event fabricated in the video is plausible as rendered. A child would be too heavy for an eagle to carry for much of a distance, but it's not impossible that one might decide to try.