Dissertation Research: Energetic Demands of Production of Young in the Chiropteran species, Phyllostomus hastatus

9321745昆兹在自然界中，成体用于繁殖的能量不仅会影响特定幼崽的存活，还会影响它产生未来后代的能力。怀孕和哺乳对女性的能量和营养要求特别高，这可能会增加她对饥饿或疾病的易感性。因此，用于怀孕和哺乳的能量必须与雌性未来的生殖潜力相平衡。还必须在平衡孕期和哺乳期之间达成妥协。与哺乳期相比，妊娠期的成本相对较低，因为营养物质可以直接转移到发育中的幼崽身上，而且体温调节成本最低。然而，运输生长中的胎儿可能会阻碍正常的日常活动，并增加捕食的风险。因此，怀孕和哺乳期间的能量消耗模式应该反映出维持和运送胎儿的成本，而不是喂养和照顾幼崽的成本。%拟议研究的目标是进行一系列野外和实验室实验，以衡量与杂食性热带蝙蝠--竹子口蝙蝠--怀孕相关的成本。每日能量消耗和分配将通过测量怀孕进行性阶段女性的实地代谢率(使用双重标记水)和身体成分(通过同位素稀释)来量化。将使用无线电遥测技术构建雌性觅食者的夜间时间预算，以检验觅食时间是满足胎儿日益增长的需求和最大限度地减少运送发育中胚胎的成本之间的权衡这一假设。将对饮食构成和营养含量进行分析，以确定饮食构成如何与怀孕造成的成本相关。这些项目的完成将与同一物种的可比数据相结合，以提供有关杂食性食性哺乳动物繁殖的成本和妥协的重要见解。

9321745 Kunz In nature, the energy an adult devotes to reproduction will affect not only the survival of a particular litter, but its ability to produce future offspring. Pregnancy and lactation place especially high energy and nutrient demands on the female, which may increase her susceptibility to starvation or disease. Thus, energy devoted to pregnancy and lactation must be counterbalanced against the female's future reproductive potential. Compromise must also be reached in balancing length of gestation against duration of lactation. Gestation is relatively inexpensive compared to lactation, as nutrients can be transferred directly to the developing young and thermoregulatory costs are minimal. However, transport of the growing fetus can impede normal daily activities and increase risk of predation. Patterns of energy expenditure during pregnancy and lactation should thus reflect the costs of maintaining and transporting a fetus versus feeding and caring for developing young.%%% The goal of the proposed research is to conduct a series of field and laboratory experiments to measure the cost associated with pregnancy in an omnivorous tropical bat, Phyllostomus hastatus. Daily energy expenditure and allocation will be quantified by measuring field metabolic rate (using doubly-labeled water) and body composition (through isotope dilution) of females at progressive stages of pregnancy. Nocturnal time-budgets of foraging females will be constructed using radio-telemetry to test the hypothesis that foraging time is a trade-off between supplying the growing needs of the fetus and minimizing the cost of transporting a developing embryo. Diet composition and nutritional content will be analyzed to determine how diet composition correlates with the cost imposed by pregnancy. Completion of these projects will be integrated with comparable data in the same species to provide important insights into the costs and compromises associated with reproduc tion in an omnivorous volant mammal.***