Prenatal stress effects on sociality, health and fitness in wild Assamese macaques

Dr. Oliver Schülke, Göttingen

PhD student: Simone Anzà


The developmental origins of health and disease are still debated. Nevertheless, it is well established that adverse conditions early in life can have long-lasting effects on immune function, systemic disease, neurodevelopment, skill acquisition and behavior in animals and humans. Thus, adult health states are sometimes better explained by early adversity than by current interactions with the environment. These effects may either be interpreted as resulting from constraints on an undisturbed development or as adaptive developmental plasticity allowing for adaptive responses to conditions predicted for later life phases. The internal predictive adaptive response (PAR) hypothesis proposes that early adversity causes developmental constraints and thus disadvantaged early somatic states that typically lead to disadvantaged somatic states later, during adulthood and consequently to reduced life expectancy. In an effort to partly compensate for reduced life expectancy the offspring is thought to adjust its life history pace: growth and reproduction are accelerated which comes, however, at the cost of reduced investment in maintenance functions and quality related attributed that would enhance longevity and offspring physical condition. With this project we aim at testing the internal consistency of the internal PAR hypothesis and predictions thereof with data on a wild, slowly developing mammal forming large groups. Our own previous work on wild Assamese macaques has established that prenatal maternal physiological stress affects offspring growth, motoric skill acquisition and infection during infancy. Here we propose a largely cross-sectional design extending the perspective to subsequent life phases all the way into adulthood. We assess whether increased prenatal maternal physiological stress measured from fecal glucocorticoid levels speeds up offspring growth, sexual maturation and reproductive rate with negative effects on offspring muscle mass, gut microbiota composition and possibly social integration and social bonding and positive effects on gastrointestinal parasite community richness, baseline physiological stress levels and reactivity of the hypothalamus-pituitary-adrenal (HPA)-axis. The study is prospective in the sense that fecal samples for assessment of physiological stress in mothers have been collected discontinuously since 2007 and outcome variables will be measured in this project. The project’s unique contribution to the general SoHaPi aim of improving the understanding of the sociality health fitness nexus is providing a developmental perspective on adult health.

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