According to the non-fiction book Searching for Ropens, by Jonathan Whitcomb, at least one species of ropen in Papua New Guinea eats fish, at least as part of its diet. But according to his second book about living pterosaurs, Live Pterosaurs in America, some similar nocturnal flying creatures in the United States fly over rivers at night. Peter Beach, a professor of biology at a college in Washington State, suspects that at least one kind may catch Night Hawk birds or bats that fly over a section of the Yakima River; this professor has seen one of the creatures, and it was too big to be a bat. Two eyewitnesses who saw the creature but not its eating are Hodgkinson (an American World War II veteran) and Hennessy (an Australian psychologist who works in China).