SINGING PERFORMANCE, FREQUENCY MATCHING AND COURTSHIP SUCCESS OF LONG-TAILED MANAKINS (CHIROXIPHIA-LINEARIS)

We examined the relationship between song performance and courtship su ccess in the lek-mating long-tailed manakin (Chiroxiphia linearis) of Costa Rica. Teams of male manakins form cooperative partnerships consi sting of a dominant alpha male and a beta male partner with a variable number of subordinate affiliates. Each alpha and beta partnership per forms a joint song virtually in unison, which attracts females to thei r lek arena. We quantified four aspects of song performance, including synchrony, degree of consistency in the alpha male's singing, degree of consistency in the beta male's singing, and degree of sound frequen cy matching between partners. When all four variables were included in a discriminant function analysis, average frequency matching alone wa s useful in discriminating between teams with high rates of visitation by females and those with low visitation rates. Only frequency matchi ng was correlated with the rate at which females visited display lek a renas. We propose that the degree of frequency matching provides an un ambiguous ideal against which dual-male courtship performance can be a ssessed. This aspect of song performance may provide information usefu l to females in assessing a potential mate's ability to form a coopera tive, long-term partnership.