The Haast eagle, Harpagornis, attacking a herd of moas
The animals listed here are birds of prey which remain unrecognised by mainstream science. These include owls and the like, but NOT flightless carnivores or pterosaurs. Both will be dealt with on their own time. This section will, however, include ravens, largely becuase they are also predatory birds, even though they do belong to the passeriforms (songbirds) and not the falconoforms (eagles, hawks, vultures) or strigiforms (owls).
Thunderbird (Eastern, Western and South Central North America): A gigantic predatory bird reported to exist across NA. It is said to be able to carry of humans, and most tribes across the continent hold it in high regards. It could be either a giant vulture, giant eagle, or giant raven. I'll go into that more later.
"big owl" (Southern and Eastern US NA): A figure in native mythology, this was supposedly a half man, half owl creature, which is always regarded as jut mythical. However, I'm going to propose that it was merely a giant owl. An owl the size of a mna could easily, through the power of myth, become an owl-man. The "mothman" phenomenon from West Virginia may be related to this.
British Columbian giant raven (Interior of B.C. NA): A piece of local folklore, the bush mechanics who worked in the interior of B.C. claim that here is a valley, rich in timber, which is populated by enormous raverns bigger than golden eagles. They say these ravens are dangerous animals, very opportunistic, and will not hesitate to tear someones camp apart. they are nearly flightless, and have much red in their tail plumage. These are obviously a specialized species of raven which developed in the isolation of this valley. However, if any introduced predators like dogs or cats make it there these ravens might become threatened.
Kikiyaon (Sengal and Gambia AFRICA): An owl-like animal reported from areas of the Congo. Most likley a new owl, or perhaps a giant nighthawk of some kind.
New Guinea giant bird (Papua New Guinea INDONESIA): A gaint, eagle-like bird that was seen by early explorers to the island. It was said to inhabit a cetain, hard to reach area of swampland near an inlet. The native Papuans say it carry off a dugong or sea turtle with ease. If such a bird exists, or existed, it may be an eagle of some kind.
Hasst eagle (New Zealand OCEANA): An enormous eagle which once lived in New Zealand before it was wiped out (pictured on this page). It could carry off humans and apparently ate moas as the staple of it's diet. However, according to an informant they are still seen today in remote areas of New Zealand mountain forest. The unlikelyhood of this is rather great, however, as I doubt that such an enormous predator, which apoparently relied on tall trees and dense forest to live in, could remain unoticed.
Devil bird (India and Sri Lanka ASIA): This is a major success for cryptozoology. in Sri Lanka and India there has long been the legend of the devil bird, a mysterious birdwhich lived in the depths of the forest and was almost never seen, but always gave out this horrific cry, sounding like some wounded and dyng human. the settlers and indigenous peoples connected it with evil and the devil becuase of this call. the few people who ever saw it said it looked kind of like a nighthawk or cuckoo. Many cryptozoologists predicted that the devil bird would turn out to be an owl of some kind. Just this year, 2001, a new owl was discovered in Sri Lanka which fit the few descriptions of the devil bird. Another cryptid proven.
Steller's "white sea-raven" (Bering Island in the Bering Straits ASIA): Steller, while stranded on Bering Island, claimed to have seen a pure white "sea-raven" flying over the ocean. It should be noted that German's at that time referred to cormorants as "sea-ravens", and Steller was German. was he describing a new kind of cormorant? a white one? you decide.