Sex-specific density-dependent secretion of glucocorticoids in lizards: insights from laboratory and field experiments

Negative density feedbacks have been extensively described in animal species and involve both consumptive (i.e. trophic interactions) and non-consumptive (i.e. social interactions) mechanisms. Glucocorticoids are a major component of the physiological stress response and homeostasis, and therefore make a good candidate for proximate determinants of negative density feedbacks. Here, we combined laboratory and field experiments with enclosed populations to investigate the relationship between density, social stress and plasma corticosterone levels in the common lizard Zootoca vivipara. This species exhibits strong negative density feedbacks that affect females more than males, and its life history is sensitive to experimentally-induced chronic elevation of corticosterone plasma levels. We found that prolonged crowding in the laboratory can trigger a chronic secretion of corticosterone independent from food restriction. In the field experiments, corticosterone levels of females were not af...

负密度反馈（Negative density feedbacks）已在诸多动物物种中被广泛报道，其作用机制涵盖消耗性（即营养级相互作用）与非消耗性（即社会相互作用）两类。糖皮质激素（Glucocorticoids）是生理应激反应与稳态维持的核心组成部分，因此是负密度反馈近因决定因素的极佳研究候选对象。本研究将室内与野外实验同封闭种群研究相结合，旨在探究胎生蜥蜴（Zootoca vivipara）的种群密度、社会应激与血浆皮质酮水平之间的关联。该物种存在强烈的负密度反馈效应，且对雌性个体的影响强于雄性；其生活史特征对实验诱导的血浆皮质酮慢性升高敏感。研究发现，实验室环境下的长期拥挤可触发不依赖食物限制的皮质酮慢性分泌。在野外实验中，雌性个体的皮质酮水平并未受……