Strategic reduction of help before dispersal in a cooperative breeder |
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| Authors: | Markus Z?ttl Lucille Chapuis Manuel Freiburghaus Michael Taborsky |
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| Institution: | 1.Department of Behavioural Ecology, Institute of Ecology and Evolution, University of Bern, 3032 Hinterkappelen, Switzerland;2.Department of Zoology, University of Cambridge, Cambridge, UK;3.UWA Oceans Institute, School of Animal Biology, University of Western Australia, Australia |
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| Abstract: | In cooperative breeders, sexually mature subordinates can either queue for chances to inherit the breeding position in their natal group, or disperse to reproduce independently. The choice of one or the other option may be flexible, as when individuals respond to attractive dispersal options, or they may reflect fixed life-history trajectories. Here, we show in a permanently marked, natural population of the cooperatively breeding cichlid fish Neolamprologus pulcher that subordinate helpers reduce investment in territory defence shortly before dispersing. Such reduction of effort is not shown by subordinates who stay and inherit the breeding position. This difference suggests that subordinates ready to leave reduce their investment in the natal territory strategically in favour of future life-history perspectives. It seems to be part of a conditional choice of the dispersal tactic, as this reduction in effort appears only shortly before dispersal, whereas philopatric and dispersing helpers do not differ in defence effort earlier in life. Hence, cooperative territory defence is state-dependent and plastic rather than a consistent part of a fixed life-history trajectory. |
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| Keywords: | cooperative breeding dispersal consistent behavioural variation life history helping Neolamprologus pulcher |
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