DragonflyIssuesInEvolution13 Wiki

Biological Ornamentation, also known as sexual ornamentation, are features or sexual signals (see video below) which can be used to help assess the quality of a mate (Kekäläinen, et al, 2010). 


Glamorous Birds - Battle of the Sexes in the Animal World - BBC

Biological ornamentation within mating

Theories Behind Ornamenation[]

Charles Darwin first proposed the idea of sexual selection  in his book The Decent of Man. Darwin proposed that biological ornamentation was important because females selected, or chose, mates who displayed elaborate plumage and/or who exhibited remarkable displays (Darwin, 1874). Ornamenation could also be utilized in male-male competition during courtship (Darwin, 1874; Kekäläinen, et al, 2010). For example the antlers of a male deer could be considered biological ornamentation that might attract a female but are also an ornamentation utilized during male-male combat, particularly during mating season (Clements, et al, 2010). 

Since Darwin's time other ideas have been proposed to explain biological ornamentation and include the Handicap Principle as well as the Bright Male hypothesis (Hamilton & Zuk, 1982; Zahavi, 1975)


Amazing! Bird sounds from the lyre bird - David Attenborough - BBC wildlife-1386089357

The lyre bird is an excellent example of sexual ornamentation. In addition to its beautiful plumage, it has the impressive ability to mimic almost any sound.

Examples of Ornamentation []

Examples of biological ornamentation can be found throughout the animal kingdom. Sexual ornamentation can be found in fish such as the Trinidadian guppies who has a rich color display (Ruell, et al, 2013). It can be found in African male lions who posses manes as sexual ornamentation (Kays, & Patterson, 2002). Ornamentation is also found in various forms within the Birds of Paradise of New Guinea (see video below). 


Birds-of-Paradise Project Introduction

Birds of Paradise exhibit biological ornamentation


Clements, M. N., Clutton-Brock, T. H., Albon, S. D., Pemberton, J. M., & Kruuk, L. B. (2010). Getting the timing right: antler growth phenology and sexual selection in a wild red deer population. Oecologia164(2), 357-368. 

Darwin, C. (1874). Descent of man. Chicago: Montgomery Ward.

Hamilton, W. D., & Zuk, M. (1982). Heritable true fitness and bright birds: a role for parasites?. Science218384-387.

Kays, R. W., & Patterson, B. D. (2002). Mane variation in African lions and its social correlates. Canadian Journal Of Zoology80(3), 471.

Kekäläinen, J., Valkama, H., Huuskonen, H., & Taskinen, J. (2010). Multiple Sexual Ornamentation Signals Male Quality and Predicts Female Preference in Minnows. Ethology116(10), 895-903.

Ruell, E., Handelsman, C., Hawkins, C., Sofaer, H., Ghalambor, C., & Angeloni, L. (2013). Fear, food and sexual ornamentation: plasticity of colour development in Trinidadian guppies. Proceedings. Biological Sciences / The Royal Society280(1758), 20122019. 

Zahavi, A. (1975). Mate selection-a selection for a handicap. Journal Of Theoretical Biology53(1), 205-214.