Complex sentence: A bright yellow pollen would produce a sharp visual contrast with the color of the beak, and the bird would be stimulated to clean his beak, a behavior which would be a reproductive disaster for the orchid.
Split into simpler sentences: A bright yellow pollen would produce a sharp visual contrast against the color of the beak, and the bird would be stimulated to clean his beak. Such a behavior which would be a reproductive disaster for the orchid.