Adaptive Advantages of Cooperative Courtship for Subordinate Male Lance‐Tailed Manakins

Abstract

Male lance-tailed manakins (Chiroxiphia lanceolata) cooperate in complex courtship displays, but the dominant (alpha) partner monopolizes mating opportunities. This raises the question of why subordinates (betas) cooperate. Three nonexclusive hypotheses explain the adaptive basis of helping behavior by subordinate males: cooperation may increase (1) subordinates' immediate reproductive success, (2) the reproductive success of close relatives, or (3) subordinates' chances of future reproduction. I demonstrated that beta males rarely sired chicks and were unrelated to their alpha partners but received delayed direct benefits from cooperation; betas had an increased probability of becoming an alpha when compared to males that had not been betas. To investigate the mechanism by which betas attain these adaptive benefits, I examined betas' success in replacing their alpha partners both in natural turnover events and when alphas were experimentally removed. Beta males did not consistently inherit alpha roles in the same territories where they served their beta tenure, arguing that queuing for status does not fully explain the benefits of cooperation for betas. Instead, betas may be apprenticing to develop effective and appropriate displays that enhance their subsequent success as alphas. Complex social affiliations appear to mediate selective pressure for cooperation in this species.Keywords: lance-tailed man akin, Chiroxiphia, cooperative courtship, relatedness, delayed direct benefits.Cooperative reproduction is a classic paradox in evolutionary biology because cooperating individuals apparently sacrifice their own reproductive potential to assist the reproductive efforts of others. Much theory about cooperation is informed by studies of cooperative breeding, in * Present address:

Sexual selection in a lekking bird: the relative opportunity for selection by female choice and male competition

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“…DNA was amplified from 20 variable microsatellite loci in multiplexed PCRs that included 5-20 ng DNA and four fluorescently labelled primer pairs (DuVal 2007a;DuVal et al 2007). PCR products were visualized on an ABI 3110 genotyper (Applied Biosystems), with one negative and two positive controls included in each genotyper run.…”

There is no fitness but fitness, and the lineage is its bearer

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