Odd Couples in Manakins: A Study of Social Organization and Cooperative Breeding in Chiroxiphia linearis

Male long-tailed manakins (Chiroxiphia linearis) perform highly specialized communal or cooperative displays to advertise their presence and to excite females for copulation. For the purpose of performing these displays, males form persistent associations (pairs or trios) analogous to those between members of heterosexual monogamous pairs. Associations persist through an entire breeding season or from year to year. One male is dominant in the association and responsible for all copulations. Evidence argues against a close kin relationship between males, and the behavior of the subordinate individual does not appear to be altruistic. The subordinate male probably receives a delayed benefit if he outlives his dominant partner. It is suggested that on re-pairing, he will assume the dominant position in the new partnership because of the psychological advantage gained as a result of his familiarity with and prior possession of the court where the displays are performed. Ultimately, his mating success will be greater than that of a solitary male who cannot perform alone, and, therefore, is incapable of attracting and exciting females. Long-tailed manakin social organization, male-male bonding, and communal courtship behavior can best be explained on the basis of selection operating on the individual.