The Dance of the Long-tailed Manakin

Charles Darwin is famous for his contributions to evolution and natural selection. He developed the theory of natural selection and further realized that there are many forms of natural selection. One of these forms is called sexual selection, which he describes in one of his famous books, The Descent of Man, and Selection in Relation to Sex. The idea rose from the observation that some organisms possess traits or exhibit behaviors that do not appear to help them survive. Examples of such cases include conspicuous plumage in birds, antlers of deer, and lekking behavior in manakins. Understanding how a physical characteristic, such as bright col-oration or antlers, has evolved is relatively simple, because they each offer one main advantage: attracting females. Bright colors help males stand out and attract female attention and antlers help males during intra-sexual selection when they compete with other males for limited resources, such as mates. However, lekking behavior is more difficult to understand, because there is no one obvious advantage for exhibiting this behavior. A lek is an area in which a group of males gather to participate in competitive displays in the hopes of enticing a female who is looking for a mate. Lekking behavior is most common in avian species, including the long-tailed manakin (Chiroxiphia linearis). These birds live in subtropical or tropical forests. Males form a group of two or more and perform elaborate displays together, in order to attract females. There is one " master " who is the older alpha male. The other males are all below him and are the " apprentices " , or beta males. Usually, the master and one apprentice will form a duo and perform a courtship display for a female. If the female is impressed by their display, she will mate. However, only the master male ever mates with the female. The apprentice male does not get to mate at all. His only chance of mating is in the future when his master dies and he gets the opportunity to replace him, which may take up to ten years (McDonald, 2007). It is clear that the apprentice male does not gain any obvious direct benefits from forming this duo. Thus, lekking behavior is a Darwinian puzzle , which means that it is a behavior that appears to reduce the fitness of the individual. This goes against the common theory of natural selection, which states …