Evelyn Cheesman (1881-1969), a British entomologist (biologist who studies insects) in the 1930’s, was puzzled by strange lights on a ridge deep in the interior of the tropical mainland of New Guinea. She later wrote a book (The Two Roads of Papua) in which she described the flash: It lasted “about four or five seconds, but that flash had been a little distance away from the first. Flashes continued at intervals. . . . by no possibility could there be human beings out there using flash-lamps at intervals . . .”
It would be decades later that a few American cryptozoologists would explore several areas of Papua New Guinea, searching for bioluminescent Rhamphorhynchoid (long-tailed) pterosaurs. Rarely have Western visitors had a good view of the features of these strange nocturnal dragon-like flying creatures, but Paul Nation, in 2006, videotaped two of the “indava” lights that he was observing only a few mountain ranges south of where the British biologist had observed strange lights many decades earlier.
Although searching for extant pterosaur cryptids has not necessarily been popular with all cryptozoologists, a few American adventurers have explored Papua New Guinea, searching for them. This seems to be a sideline of cryptozoology, not as popular as Big Foot searches.