Look at the eyewitnesses. They’re from Malaysia, Papua New Guinea, Australia, the Philippines, the United States, Great Britain, Sudan, and many other countries around the world. What do you see? Common (and sometimes uncommon) persons of many occupations, languages, and beliefs. They seem to have nothing in common except that they have seen a pterosaur or pterosaur-like creature and they have spoken to someone about what they have seen.
Consider Papua New Guinea. For Umboi Island, eyewitnesses have included an Australian who served in a government position there, a native government leader, many common villagers, and a visiting cryptozoogist. For other areas of P.N.G., they have included an Australian psychologist, American expedition members of a television true-life adventure series, an American World War II soldier, a British entomoligist (biologist), missionaries, a non-missionary visiting a mission, many common villagers, a minister, and a visiting cryptozoologist.
Consider other areas of the Southwest Pacific. Eyewitnesses have included an Australian scientist and his wife, an Australian farm boy, a real estate agent, school-aged children, a pilot and co-pilot of a small plane, sailors on an American military ship, and common villagers.
Consider the United States. Eyewitnesses have included an attorney, a business owner, a hospital lab employee, an artist working for a silkscreening company, farmers, a fireman, teenagers, school-aged children, elementary school teachers, an ambulance driver, a minister, a plane pilot, and several cryptozoologists.
The eyewitnesses are as varied as we would expect of persons who each just happened to be in the right place at the right time, to witness a living creature rare enough and usually-reclusive enough to remain undiscovered by Western science.
Australian eyewitness: the psychologist Brian Hennessy
Analysis of two interviews of Gideon Koro on Umboi Island: How many ropens?