title: Delayed dispersal and the costs and benefits of different routes to independent breeding in a cooperatively breeding bird.
abstract: Why sexually mature individuals stay in groups as nonreproductive subordinates is central to the evolution of sociality and cooperative breeding. To understand such delayed dispersal, its costs and benefits need to be compared with those of permanently leaving to float through the population. However, comprehensive comparisons, especially regarding differences in future breeding opportunities, are rare. Moreover, extraterritorial prospecting by philopatric individuals has generally been ignored, even though the factors underlying this route to independent breeding may differ from those of strict philopatry or floating. We use a comprehensive predictive framework to explore how various costs, benefits and intrinsic, environmental and social factors explain philopatry, prospecting, and floating in Seychelles warblers (Acrocephalus sechellensis). Not only floaters more likely obtained an independent breeding position before the next season than strictly philopatric individuals, but also suffered higher mortality. Prospecting yielded similar benefits to floating but lower mortality costs, suggesting that it is overall more beneficial than floating and strict philopatry. While prospecting is probably individual-driven, although limited by resource availability, floating likely results from eviction by unrelated breeders. Such differences in proximate and ultimate factors underlying each route to independent breeding highlight the need for simultaneous consideration when studying the evolution of delayed dispersal.
authors.affiliation: Behavioural & Physiological Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700CC, Groningen, The Netherlands. sjoukeannekingma@gmail.com.|Centre for Ecology, Evolution and Conservation, School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom. sjoukeannekingma@gmail.com.
authors.forename: Sjouke A
authors.initials: SA
authors.lastname: Kingma
authors.affiliation: Centre for Ecology, Evolution and Conservation, School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom.
authors.forename: Kat
authors.initials: K
authors.lastname: Bebbington
authors.affiliation: Behavioural & Physiological Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700CC, Groningen, The Netherlands.
authors.forename: Martijn
authors.initials: M
authors.lastname: Hammers
authors.affiliation: Centre for Ecology, Evolution and Conservation, School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom.|Nature Seychelles, Mahé, Seychelles.
authors.forename: David S
authors.initials: DS
authors.lastname: Richardson
authors.affiliation: Behavioural & Physiological Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700CC, Groningen, The Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Komdeur
mesh_terms: D025041:Animal Migration; D000818:Animals; D001947:Breeding; D019143:Evolution, Molecular; D005260:Female; D008297:Male; D012098:Reproduction / Q000235:genetics; D020308:Songbirds / Q000235:genetics* / Q000502:physiology
keywords: Benefits-of-philopatry; cooperative breeding; delayed dispersal; ecological constraints; informed dispersal; reproductive skew