A hunter is attacked and killed by what looks like a man-sized pteradactyl after his hunting partner calls him a "dumbutt". I guess that jinxed him. The other guy gets away but is scratched. Eventually he ends up at the nearby hospital where they do a blood test and discover he has some mutated form of bird flu. It's not only making him sick it's making him look like a rotting zombie. I didn't know any type of flu did that. Anyways, the main story concerns a group of bad teenagers who are in prison camp. The guy in charge gets killed by the "birds" and so they must try to make it out of the forest alive while these flying lizards pick them off one by one. There's also the government agents, with Romanian accents, who want to stop the infection from spreading to a population of millions. In fact, I think this whole movie was shot in Romania as many of the voices seem as if they are dubbed in. Of course, the birds are killed in the end by a character who sacrifices/redeems himself and there's a big explosion, with the hint that the "birds" aren't all dead. You've seen this movie a zillion times before.