Flexible compensation of uniparental care: things are not always what they seem

• Ano de defesa: 2017
• Autor(a) principal: Plasier, Sergio Nolazco
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Amphisexual care; Canibalismo filial; Cuidado amphisexual; Cuidado facultativo; Esforço de acasalamento; Esforço parental; Facultative care; Filial cannibalism; Mating effort; Parental effort
• Link de acesso: http://www.teses.usp.br/teses/disponiveis/41/41134/tde-18042017-105356/

In some species with uniparental care, when the parental individual deserts the offspring or dies, its mate may adopt the parental responsibilities, a behaviour known as flexible compensation of uniparental care. However, for most of the species in which this behavioural response has been reported in the literature, there was no thorough investigation of its effects upon offspring fitness to support it. In the Neotropical harvestman Serracutisoma proximum, a species with female uniparental care, harem-owning males stand on unattended clutches when the egg-tending females desert or die. Here, we investigate if this species constitutes an actual example of flexible compensation of uniparental care by evaluating the effects of ecological (namely climatic conditions and mate availability) and life-history factors (namely male attractiveness, clutch size and filial cannibalism) on males\' behaviour and, ultimately, on offspring survival. We expect unfavourable climatic conditions, as well as low mate availability and male attractiveness, to negatively affect the exhibition of compensatory behaviours, but a positive effect of clutch size. Moreover, we expect an increase in the extent of filial cannibalism to be a strategy that alleviates the costs of compensation. However, males\' behaviour towards unattended offspring has no effect on offspring survival, and other results were inconsistent with our predictions except for climatic conditions affecting the extent of both the presumed behaviour of standing on unattended clutches and filial cannibalism. Our results, therefore, do not support the existence of flexible compensation of uniparental care in S. proximum. Rather than a parental activity, we argue that males’ behaviour corresponds to a mating tactic that increases fertilization and mating success with the returning egg-tending females or newcomer mates foraging on the unattended offspring. This study demonstrates that for presumed cases of flexible compensation of uniparental care it is necessary to evaluate the effects on offspring fitness since not always an apparent parental behaviour is what it seems to be