If you ever look at animals in the wild, you may notice that females are often less colorful than males. This is especially common in birds, whose females are usually brown or grey while males sport brilliant colors. Now, scientists have found that females may be so drab in order to avoid sexual harassment.

Males often attract females through the use of distinctive plumage, markings or displays of some kind or other. With that said, males can also be picky about which mate they choose - so why don't females also display some kind of distinctive plumage?

In the past, researchers suggested that females remain drab in order to avoid being eaten by predators. In other words, females match the background in order to stay alive and keep their young safe through the use of camouflage. However, this doesn't completely explain why females are so drab.

"If we accept the premise that males, while not as choosy as females, still exert some choice of mate, then the question is why don't females signal their sexual quality via ornamental sexual traits like males do?" asked David Hosken, one of the researchers and a professor at the Center for Ecology & Conservation at the University of Exeter's Cornwall Campus in the United Kingdom. "We suggest that if female ornaments signaled their sexual quality, females could suffer increased sexual harassment by males and this could be especially costly to fitness."

Female animals, such as birds, often go to great lengths to avoid sexual harassment and signal their unattractiveness. They will often disguise themselves as males or move to areas where there are fewer males. Some species even use anti-aphrodisiacs or fight off unwanted copulation.

"We are not suggesting that male harassment of attractive females is the only explanation for lack of sexual ornamentation in females, but want to alert researchers to the idea that this could be a contributing factor," Hosken said.

The findings could mean that birds and other animals could have less brightly colored females partly because females are avoiding unwanted attention from males. This could help with rearing offspring - by avoid males, females would be able to concentrate on rearing their brood. With that said, this doesn't mean that this is the only reason for drab feathers.

The findings were published in the April journal Animal Behavior.