Collaborative Research: Parental care and the integration of personality and plasticity at multiple levels of phenotypic variance

  • Westneat, David (PI)
  • Bonner, Simon (Former CoI)
  • Schofield, Matthew (Former CoI)

Grants and Contracts Details


A hierarchical structure of phenotypic variance is an essential concept in evolutionary biology. Important biological processes depend on this hierarchy and influence its structure. For labile traits like behavior, this structure is incompletely defined, with some variances under-explored and some covariances incompletely understood. For example, the trait of focus in this proposal, parental care, is an important behavioral component of life history and yet several components of variation and covariation in parental care are not well studied. Parental behavior of house sparrows will be measured and variance separated into its constituent components. Manipulations of brood demand will test among two alternative hypotheses about covariance between individual plasticity and personality in parenting. A novel statistical technique will be used to assess patterns of stochasticity in parental behavior. Additional experiments using controlled feeders in both free-living and captive subjects will test if heterogeneity is a byproduct of decisions about mean provisioning or adaptive management of stochastic variance. Finally, measurements of hormone levels in response to the experiments as well as a novel experiment in which two hormones will be manipulated will test alternative hypotheses about the underlying mechanisms that influence phenotypic variance in parental behavior. Intellectual merit: This project will expand understanding of phenotypic variation, theory regarding parental care, and the analysis of labile traits. The novel conceptual approach used and the data collected will extend the hierarchical structure of variance in new directions, integrating previously disparate concepts. New insights regarding plasticity and consistent individual differences in mean and variance in behavior will be gained. Patterns of stochastic variance will be measured and the results will stimulate new ideas about stochasticity in evolutionary theory including adaptive variance sensitivity (a form of canalization) and trickle-up effects such as bet-hedging. The hypothesis that parents adaptively manage their exposure to variance in food supply will be explicitly tested, and this too will steer theory on parenting behavior in new directions. The specific studies undertaken here will be combined with data from other species to provide general tests of ecological effects, and stimulate new theory about parental care specifically and phenotypic variance more generally. The hormone studies will integrate ecology with physiology through a reaction norm approach and the impact of hormones on components of behavior with ecological relevance will be assessed. In general, the integrated study of parental care will develop a model example of a phenotype exhibiting the full hierarchy of variance, leading to a better understanding of the evolution of reaction norms. Broader impacts: This project has multiple impacts beyond a new approach to studying behavior. The continued development of statistical methods to model means and variances interactively will have broad effects on the study of any labile trait, including behavior and physiology. Conceptually, it will lead to renewed focus on stochastic variance as an important element of an ecological view of phenotypic evolution. The project also explicitly includes mechanisms to enhance integration of biology and statistics through both application and training. The project will enhance a well-tested mentoring approach, which will significantly impact the development of young scientists at multiple levels and provide them with an unusual mix of experiences. It will explicitly incorporate biological and statistical training of high school, undergraduate, and graduate students. It strengthens ties to several special intern programs in Kentucky that focus on developing research experiences for underrepresented groups (minorities and students from Appalachia). In addition, students in biology and statistics will gain unique exposure to both fields through a cross-discipline working group that may form a model for a center for ecological statistics. Finally, the project will assist efforts to expand global interactions in science by increasing communication and active sharing of data among an international group of researchers and students.
Effective start/end date8/1/137/31/18


  • National Science Foundation: $677,140.00


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