Sexual ornamentation is a featured physical characteristic of an organism which can indicate their dominant role in a social heirarchy. These ornaments can be critical as a means to establish dominance without relying directly on physical contact or confrontation (Freeman, S and Herron, J, 2007).
Sexual ornamentation can indicate to a female that a male inhabits or protects a territory that has abundant resources.
Sexual Ornamentation Evolution
Sexual ornamentation relies on the breeding of females to males with outstanding ornamentation, such as
female greater birds of paradise breeding with male greater birds of paradise with colorful plumage. This, in turn, leads to the colorful plumage gene carrying on. However, if the colorful plumage gene carries on throughout the population then females begin breeding with the males that have the most outrageously colorful plumage, thus driving the evolution of sexual ornamentation (Badyaev, A.V., 2004).
However, it is important to note that some sexual ornamentation can become a hinderance to survival. For instance the Jackson's widowbird maintains a dull coat for most of the year, but during breeding season sports a long tail. This tail can make it difficult to fly, make the bird easier to spot by predators, and may lead to the bird's capture. Sexual ornamentation, particularly in birds, may become a hinderance to flight and camouflage.
Freeman, S. & Herron, J. (2007). Evolutionary Analysis 4th Ed. Sexual Selection, pp 401-441.
Badyaev, A.V. (2004) Developmental perspective on the evolution of sexual ornaments. Evolutionary Ecology Research, 975-991.