Many Flytrap monsters are named ___trap, with ___ representing some creature. Birdtrap means this plant catches birds in it, presumably the small vulture/crow type. What bird it preys on is unknown as no bird monsters seen in its zone. It may refer to not birds the monster correlation or vulture family, but birds in general, such as small songbirds. However, this name may or may not be literal and may merely be an exaggeration or instance of creative naming.