This is the only manbird movie I know of by: MystMoonstruck
The Vulture (1967)
IMDb review (edited for length): ***SPOILERS*** American atomic researcher Eric Lutens (Robert Hutton) arrives in Cornwall for a rest, planning to visit several members of his wife Trudy's (Diane Clair) family. However, strange things have been happening in the area. A schoolteacher taking a shortcut through a graveyard has had a shock that has turned her hair white. Livestock have been vanishing without a trace. The discovery of a gold coin and an opened grave brings to light a peculiar local legend. Centuries before, Francis Real was suspected of witchcraft, was seized then buried alive with his pet~a strange vulture-like bird~and a casket of gold coins. He swore to destroy the descendents of the local squire who had overseen his burial. The story disturbs Eric, as the cursed man is Trudy's ancestor. A gamekeeper reports a very large bird over the estate owned by Trudy's older relative, Brian Stroud (Broderick Crawford). We now meet Prof. Koniglich (Akim Tamiroff), a local antiquarian with an interest in science, and Brian's brother, Edward (Gordon Sterne). Koniglich, who takes the tale as seriously as Eric, gets about with difficulty, using canes, the result of an accident. Eric decides that someone has conducted an experiment, creating this creature. Evidence mounts that there may indeed be some terrible creature lurking nearby. A missing sheep is found torn to bits in a cliffside cave. Then, both Stroud brothers are carried off and killed. Eric, who has been investigating power usage in the region, is contacted by the power company. The only odd thing they have found is that the professor stopped using electricity from their lines entirely and installed his own generators. Eric realizes that the professor must be the culprit and that Trudy is the final victim. He races back to town, even as she's snatched from an isolated road near the professor's home by something with claws that swoops down from above. At the professor's home, Eric finds a nuclear-powered lab in the basement. A skeleton sits at a control panel, and a casket of gold coins lies on a nearby counter. During his attempt to retrieve the treasure from its burial place, the professor ended up with his atoms mixed with the bird's remains, after which the composite creature broke out of the grave. During a final battle, the professor is revealed to have a gigantic bird's body beneath the cloaked coat he'd always worn.
That's my best guess!
Dec 25, 2009 Rating
'Blood Freak' by: Anonymous
Could be Blood Freak (1972). Man turns into turkey and kills people.