Sexual selection, which is a subset of natural selection, is defined as "selection based on mate choice." It usually, but not always, takes the form of males competing for access to females, and results in the development of either armaments in males that help them compete in the battle for mates (antlers on deer, horns on stag beetles, etc.), or bright plumage, coloration, adornments, calls, or behaviors of males that catch the fancy of females (the bowers of bowerbirds, the plumage, colors, and strange behaviors of the New Guinea birds of paradise, the songs of male frogs, etc.).
