Rules of death across ontogeny in sexually dimorphic mammals

在许多动物中，雄性体型明显较大，在不同的栖息地觅食，死亡率高于雌性。虽然生理限制、行为策略和捕食者-猎物相互作用被认为是身体大小和死亡率之间的可能联系，但它们的相对重要性尚不清楚。这个项目将确定北象海豹体型庞大的好处和后果，在北象海豹中，成年雄性海豹比雌性海豹大6倍。潜水能力和食物需求将被量化，并对从出生到四岁的男性和女性进行比较。在它们觅食的迁徙过程中，每只海豹都将携带一个新开发的生物仪，即使动物在海上死亡，它也会通过卫星传输潜水行为、迁徙路线和觅食成功的数据。找出导致雄性和雌性之间觅食栖息地和死亡率差异的机制，将改变我们对包括海洋哺乳动物和鸟类在内的顶级捕食者的理解，这些捕食者对世界各地的生态系统产生重大影响。该项目还将在传统上生物学代表性较低的学生中建立研究能力，并通过一个互动的动物跟踪网站为K-12学生和公众提供教育机会。对于性别大小的二态物种，尚不清楚饥饿和捕食等生态过程如何影响雄性和雌性不同的生理和行为表型。该项目旨在确定在个体发育过程中，男性和女性的体型差异如何导致对风险-回报格局的不同使用。雄性和雌性北方象海豹将被麻醉，测量，称重，测量仪器，并从出生到四岁取样。由此产生的数据将把三个生物学学科联系起来：潜水发展和能量需求的生理测量，由于生理限制对三维空间使用和饮食的行为划分，以及生理和生态位划分变化的生态后果。对所有海豹、海狮和海象物种的荟萃分析将被用来评估性别特有的死亡率如何与一夫多妻制的程度和更广泛的性别大小二型性相关。这些目标加在一起，将决定生态风险和回报如何与生理限制相互作用，以驱动性二态哺乳动物行为策略的个体发育。这一奖项反映了NSF的法定使命，并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，被认为值得支持。

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.