How do the animals benefit from iridescence?
Biologists hypothesize that animals use iridescence for a variety of reasons. Color is used to pass information visually from one organism to another. The Morpho male uses its blue flashing wings to signal to other Morpho males to stay out of his territory. Many birds signal their mates with iridescent patches. Hummingbirds have such patches on their necks and heads, pigeons have iridescent rings around their necks. Some researchers have found that females will be more attracted to males who show less iridescence. It appears that parasite infestation increases the iridescence. Females try to avoid males infested with parasites. Some bad tasting beetles advertise that fact with green iridescence and birds avoid them. Optical effects associated with iridescence in certain parts of the spectrum depend on how the receiving visual system processes the information. What we see may not be what a predator may see. A bug, brightly colored to us, may look like a water droplet to a predator. Irid
