LTREB: Pace of life and differential migration in changing environments

几千年来，人类一直对许多动物为了寻找食物、繁殖和生存而进行的长途迁徙着迷。近几十年来，科学家观察到越来越多的动物没有像它们的祖先那样迁徙。为什么有些人短暂地停止了迁徙，而另一些人则继续采取传统的长途迁徙？这些行为变化对迁徙物种会产生什么后果？这对人类社会有何影响？通过对白雁进行一项独特的长期研究，研究人员将通过研究气候变化和个体的繁殖历史（迄今为止养育了多少只婴儿）对迁徙距离的双重影响，以及迁徙决策对未来生存和繁殖机会的影响来解决这些问题。然后，该团队将量化每种类型的迁徙行为对大雁总体丰度的贡献。白雁作为太平洋沿岸鳗草的主要食草动物，影响沿海经济，而太平洋沿岸也是无数鱼类和贝类物种的繁殖地。如果没有丰富的麸皮来维持健康的鳗草床，也没有充分了解影响麸皮丰度的因素，依赖鳗草河口的渔业可能会受到影响。在开展研究的同时，该团队将在 STEM 领域培训高度多元化的学生群体，包括阿拉斯加原住民学生。该团队还将为 K-12 学生开发涵盖野生动物采样技术和模型的开放式教育材料。与其他类群一样，随着气候变暖以及更南边的栖息地受到人类破坏，许多鹬类动物会短暂停止季节性迁徙并在高纬度地区过冬。但许多人继续投资于向南纬地区进行传统的长途迁徙，随着时间的推移，在布兰特种群中形成了不同的迁徙策略模式。通过对阿拉斯加布兰特的长期研究，研究人员将测试环境变化是否允许个体布兰特从广泛的迁徙策略中平等地进行选择，或者环境变化是否有方向性地有利于与生命史节奏（快与慢的生殖投资和寿命）相关的特定迁徙策略（长距离与短距离），通过终生进化适应性的货币来衡量。建模还将揭示个体迁徙策略对布兰特种群生存能力的贡献，以及布兰特种群对它们所吃草的生态系统的影响。该奖项反映了美国国家科学基金会的法定使命，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。

For millennia, humans have been fascinated by the long-distance migrations that many animals undergo to find food, reproduce, and survive. In recent decades, scientists have observed that more and more animals are not migrating as far as their ancestors did. Why is it that some individuals stop their migration short while others continue to adopt traditional, long-distance migrations? What are the consequences of these changing behaviors for migratory species, and how does this impact human societies? Using a unique long-term study of brant geese, the researchers will address these questions by studying the dual influence of climate change and an individual’s reproductive history (how many babies they have reared to date) on migration distance, and the impact of migratory decisions on future chances of survival and reproduction. The team will then quantify the contribution of each type of migration behavior to the overall abundance of brant geese. Brant geese affect coastal economies via their role as primary grazers of eelgrass along the Pacific Coast, the same habitat that serves as the rearing ground for a myriad of fish and shellfish species. Without an abundance of brant to maintain healthy beds of eelgrass, and a solid understanding of the factors affecting brant abundance, the fishing industries that rely on eelgrass estuaries could suffer. While carrying out the study, the team will train a highly diverse group of students, including Alaska Native students, in STEM fields. The team will also develop open educational materials covering wildlife sampling techniques and models for K-12 students.Like other taxa, many brant are stopping their seasonal migration short and wintering at high latitudes as the climate warms and as habitats further south are damaged by humans. But many individuals continue to invest in traditional long-distance migrations to southern latitudes, creating a divergent pattern of migration tactics within brant populations over time. By leveraging a long-term study of brant in Alaska, the researchers will test whether environmental change is allowing individual brant to choose equally from a broad range of migration strategies, or if environmental change is directionally favoring a particular migration strategy (long- vs. short-distance) associated with life-history tempo (fast vs. slow reproductive investment and lifespans), as measured via the currency of lifetime evolutionary fitness. Modeling will also reveal the contributions of individual migration tactics to brant population viability, and the impact of brant populations on the ecosystems they graze.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.