Energetics of Mammalian Reproduction and Life History

小行星9309994 自1984年以来一直在研究的金背地松鼠种群的生殖能量消耗，身体状况和生殖成功之间的关系将进行调查。 拟议研究的生理方面侧重于自然条件下的密集生理表现-最大生产和最大工作负荷，以及随之而来的能量需求。 这方面的两个典型案例是发生在哺乳期女性的父母生产支出峰值和发生在男性与交配，侵略和防御相关的行为支出峰值。 在研究的每个方面，根据近端能量平衡及其表型变异量化性能，然后根据人口统计学评估最终成功，即，生存和未来的繁衍。 日常能量消耗的直接关系，以及身体质量和生存状况的中介关系，将进行检查，认识到生殖性能可能会在类似的峰值水平为所有成员的人口和由此产生的生殖输出是单独优化。 在自由生活的动物中，我们使用稳定同位素测量能量消耗，并通过全身电导率测量身体状况（脂肪与瘦肉成分）。 雌性生殖、摄入和支出的上限将通过实验操纵母体食物供应来研究。 越冬能量平衡将通过无线电遥测冬眠松鼠的休眠模式进行评估。 灵活性和可变的一岁男性生殖成熟度将在能量平衡和能量供应的实验操作方面进行评估。 这项研究应该有助于综合理解在一个群体中个体的生理和行为的变化如何转化为生存和繁殖成功的表达在整个生活史的过程中。 ***

9309994 Kenagy The relationship between reproductive energy expenditures, body condition and reproductive success will be investigated in a population of golden-mantled ground squirrels that has been under study since 1984. The physiological dimension of the proposed research focuses on intensive physiological performances under natural conditions -- maximal production and maximal work load, and the accompanying demand for energy. Two model cases of this are the peak parental production expenditures that occur in lactating females and the peak behavior expenditures that occur in males associated with mating, aggression and defense. In each aspect of the study, performances are quantified in terms of proximal energy balance and its phenotypic variation, and then the ultimate success will be evaluated in terms of demography, i.e., survival and future reproduction. The direct relationship of daily energy expenditure, and the intermediary relationship of body mass and condition to survival will be examined, recognizing that reproductive performances may operate at similar peak levels for all members of a population and that the resulting reproductive output is individually optimized. In freeliving animals we measure energy expenditure using stable isotopes, and body condition (fat vs. lean components) by total body electrical conductivity. The upper limits of female reproduction, intake and expenditure will be investigated by experimentally manipulating maternal food supply. Overwinter energy balance will be evaluated by radiotelemetry of torpor patterns in hibernating squirrels. Flexibility and variable reproductive maturity in yearling males will be evaluated in terms of energy balance and an experimental manipulation of energy supply. This research should contribute to an integrated understanding of how variation in the physiology and behavior of individuals in a population translates into the expression of survival and reproductive success over the cou rse of life history. ***