title: Nepotism and subordinate tenure in a cooperative breeder.
abstract: In many cooperatively breeding societies, subordinate individuals delay dispersal and independent breeding. The length of time that subordinates delay dispersal (subordinate tenure) is likely to have important implications for both subordinate and dominant fitness. However, quantitative comparisons of the subordinate tenure of males and females are rare, especially with respect to the presence of same- versus opposite-sex close kin. Here, we investigate subordinate tenure and how it is affected by the genetic relationship between subordinates and dominants in the cooperatively breeding southern pied babbler (Turdoides bicolor). We find that for males, longer subordinate tenures result in increased likelihood of attaining dominance. In the presence of an unrelated dominant male, tenure of subordinate males is significantly shorter, indicating nepotism among males. Female tenures are unaffected by the genetic relationship to either the dominant male or female. These results are some of the first to demonstrate that the sex of both the dominants and subordinates, and the genetic relationship between them, can have significant impacts on subordinate tenure and dispersal delays. Nepotism has likely played a vital role in the evolution of cooperative breeding in this species.
authors.affiliation: Percy FitzPatrick Institute of African Ornithology, DST NRF Centre of Excellence, University of Cape Town, Rondebosch 7701, South Africa Department of Forest and Conservation Sciences, University of British Columbia, 2424 Main Mall, Vancouver, British Columbia, Canada V6T 1Z9 martha.nelson-flower@ubc.ca.
authors.forename: Martha J
authors.identifier: 0000-0001-6753-9252
authors.initials: MJ
authors.lastname: Nelson-Flower
authors.affiliation: Percy FitzPatrick Institute of African Ornithology, DST NRF Centre of Excellence, University of Cape Town, Rondebosch 7701, South Africa Centre for Evolutionary Biology, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
authors.forename: Amanda R
authors.initials: AR
authors.lastname: Ridley
mesh_terms: D000818:Animals; D001947:Breeding; D003299:Cooperative Behavior; D005260:Female; D008297:Male; D046109:Passeriformes; D012098:Reproduction
keywords: cooperative breeding; delayed dispersal; nepotism; subordinate tenure