title: A trade-off between reproductive investment and maternal cerebellum size in a precocial bird.
abstract: Natural selection favours increased investment in reproduction, yet considerable variation in parental investment is observed in natural populations. Life-history theory predicts that this variation is maintained by a trade-off between the benefits of increased reproductive investment and its associated costs for the parents. The nature of these costs of reproduction, however, remains poorly understood. The brain is an energetically highly expensive organ and increased reproductive investment may, therefore, negatively affect brain maintenance. Using artificial selection lines for high and low prenatal maternal investment in a precocial bird, the Japanese quail (Coturnix japonica), we provide experimental evidence for this hypothesis by showing that increased prenatal provisioning negatively affects the size of a particular brain region of the mother, the cerebellum. Our finding suggests that cognitive demands may constrain the evolution of parental investment, and vice versa, contributing to the maintenance of variation in reproductive behaviour in animal populations.
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: Christina
authors.initials: C
authors.lastname: Ebneter
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
authors.forename: Joel L
authors.identifier: 0000-0002-6295-3742
authors.initials: JL
authors.lastname: Pick
authors.affiliation: Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland barbara.tschirren@ieu.uzh.ch.|Centre for Ecology and Conservation, University of Exeter, Penryn TR10 9FE, UK.
authors.forename: Barbara
authors.identifier: 0000-0003-4806-4102
authors.initials: B
authors.lastname: Tschirren
mesh_terms: D000818:Animals; D002531:Cerebellum / Q000502:physiology*; D003370:Coturnix / Q000235:genetics / Q000502:physiology*; D005260:Female; D008297:Male; D009929:Organ Size; D012098:Reproduction; D012641:Selection, Genetic; D012727:Sex Characteristics
keywords: brain size; cost of reproduction; life-history evolution; parental care; reproductive investment; trade-off