Rules of death across ontogeny in sexually dimorphic mammals

在许多动物中，雄性明显较大，在不同的栖息地觅食，死亡率高于雌性。虽然生理限制，行为策略，捕食者-猎物的相互作用已被提出作为可能的身体大小和死亡率之间的联系，他们的相对重要性是未知的。该项目将确定北方象海豹大体型的好处和后果，其中成年雄性比雌性大6倍。从出生到四岁，男性和女性的潜水能力和食物需求将被量化和比较。在觅食迁徙过程中，每只海豹都将携带一个新开发的生物记录器，即使动物在海上死亡，也能通过卫星传输潜水行为、迁徙路线和觅食成功率的数据。确定导致雄性和雌性之间觅食栖息地和死亡率差异的机制将改变我们对顶级捕食者的理解，包括对世界各地生态系统产生强烈影响的海洋哺乳动物和鸟类。该项目还将在生物学传统上代表性不足的学生中建立研究能力，并通过互动式动物跟踪网站为K-12学生和公众提供教育机会。对于性别大小的二态物种，目前还不知道如何生态过程，如饥饿和捕食作用于不同的生理和行为表型的男性和女性。这个项目的目的是确定男性和女性的身体大小差异在整个个体发育过程中如何导致风险回报景观的不同使用。雄性和雌性北方象海豹将被麻醉，测量，称重，仪器，并从出生到四岁取样。由此产生的数据将连接三个生物学科：潜水发展和能源需求的生理测量，三维空间使用和饮食的行为分区，由于生理限制，以及生理和生态位分区变化的生态后果。所有海豹，海狮和海象物种的荟萃分析将用于评估性别特异性死亡率如何与一夫多妻制和性别大小二态性的程度更广泛的相关性。总之，这些目标将确定生态风险和回报如何与生理约束相互作用，以推动性二形哺乳动物行为策略的个体发育。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

In many animals, males are notably larger, forage in different habitats, and experience higher mortality than females. Although physiological constraints, behavioral strategies, and predator-prey interactions have been proposed as possible links between body size and mortality, their relative importance is unknown. This project will determine the benefits and consequences of large body size in northern elephant seals, in which adult males are 6x larger than females. Diving abilities and food requirements will be quantified and compared between males and females from birth to age four. During their foraging migrations, each seal will carry a newly-developed biologger that transmits data on diving behavior, migration route, and feeding success via satellites even if animals die at sea. Identifying the mechanisms that drive differences in foraging habitat and mortality rates between males and females will transform our understanding of top predators including marine mammals and birds that exert strong influences on ecosystems around the world. The project will also build research capacity among students traditionally underrepresented in biology and provide education opportunities for K-12 students and the public through an interactive animal tracking website. For sexually size dimorphic species, it is unknown how ecological processes such as starvation and predation act upon the disparate physiological and behavioral phenotypes of males and females. This project aims to determine how male and female body size differences throughout ontogeny lead to divergent use of the risk-reward landscape. Male and female northern elephant seals will be anesthetized, measured, weighed, instrumented, and sampled from birth through age four. The resulting data will link three biological disciplines: physiological measurements of diving development and energy demands, behavioral partitioning of 3-dimensional space use and diet due to physiological constraints, and ecological consequences of variation in physiology and niche partitioning. A meta-analysis across all seal, sea lion, and walrus species will be used to evaluate how sex-specific mortality rates correlate with the degree of polygyny and sexual size dimorphism more broadly. Together, these aims will determine how ecological risk and reward interact with physiological constraints to drive the ontogenetic development of behavioral strategies in sexually dimorphic mammals.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.