I saw this movie on TV back in the 80's. I believe, however that it was made most likely in the 70's based on it's film style. The movie was in color. The only parts I can really remember was at the end our heroes confronted there enemy (a mad scientist type) in his lair. I believe his lair was in a volcano or perhaps a cave. The "mad scientist" used his technology to either transplant brains from his victims into other creatures or perhaps just there consciousness. I can't remember. At the end though one of his creations (if memory serves it was a woman who had been implanted into a gryphon like creature) attacks him allowing our heroes to escape. Does this information sound familiar to anyone?
Could this be The Twilight People from 1972?
This is the only "Island of Dr. Moreau" rip-off/tribute I can think of that had any flying type creature in it. It also has a scientist who is experimenting with animal/human hybrids, he has a lab in a mountain? or volcano and it takes place on an island.
Could this be "Latitude Zero" (1969)?
The plot involves people being rescued and brought to a base in a mountain on an island by a submarine. Here is part of the plot synopsis from Wikipedia that describes the gryphon type creature and the brain transplants.
Latitude Zero is a paradise hidden fifteen miles below the surface at the intersection of the Equator and the International Date Line. Gold is plentiful there and is used for protective clothing by the island's newcomers, while those who arrived in the 19th century prefer to dress as they are accustomed, as no one ages or dies. Diamonds are very common and used only in industrial use.
Dr. Malic, however, wishes to destroy the paradise of Latitude Zero, and uses giant rats and anthropomorphic bats in addition to James Bond-style devices against the undersea kingdom. Worst of all, after a cruel experiment grafting the wings of an eagle to a lion, he removes the brain of the unsuccessful Kuroi and places her brain in the creature. This proves to be his undoing when, at a critical moment, Kuroi turns against Malic as he prepares to fire an energy cannon at the escaping visitors, causing their destruction.
You can see the 'gryphon' at 1:17 in the trailer and the part where he takes out the brain of the woman to put into the gryphon at 1:38. You also get glimpses of animal/human hybrids and the volcano.