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

9321745 Kunz在自然界中，成年人用于繁殖的能量不仅会影响特定幼崽的生存，还会影响其产生未来后代的能力。怀孕和哺乳期对女性的能量和营养需求特别高，这可能会增加她对饥饿或疾病的敏感性。因此，用于怀孕和哺乳的能量必须与女性未来的生殖潜力相平衡。在平衡妊娠期和哺乳期的长短方面也必须达成妥协。与哺乳相比，妊娠相对便宜，因为营养物质可以直接转移到发育中的年轻人身上，并且体温调节成本最低。然而，运输成长中的胎儿会妨碍正常的日常活动，并增加捕食的风险。因此，妊娠期和哺乳期的能量消耗模式应反映出维持和运输胎儿与喂养和照顾发育中的幼崽的成本。拟议研究的目标是进行一系列实地和实验室实验，以测量与杂食性热带蝙蝠（Phyllostomus hastatus）怀孕相关的成本。将通过测量妊娠进行期雌性动物的田间代谢率（使用双标记水）和身体组成（通过同位素稀释）来量化每日能量消耗和分配。夜间时间预算的觅食女性将使用无线电遥测来测试的假设，觅食时间是一个权衡之间提供胎儿的成长需要和最大限度地减少运输胚胎发育的成本。将分析饮食组成和营养成分，以确定饮食组成与妊娠所需费用的相关性。这些项目的完成将与同一物种的可比数据相结合，以提供对杂食性飞行哺乳动物生殖相关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.***