Patterns of community assembly and evolution of body size variation in the Accipiter-complex, a cosmopolitan hawk clade

虽然鹰是最具魅力的鸟类群体之一，但令人惊讶的是，我们对鹰的物种之间是如何联系的，它们的群落是如何在地球历史上聚集在一起的，甚至是我们这个星球上有多少物种，我们知之甚少。特别是，生活在偏远岛屿上的鹰鲜为人知，许多被认为是单一分布物种的成员，但居住在岛屿上的几个鹰种群足够独特，应该被认为是这些岛屿特有的独立物种。使用下一代DNA测序，这项研究正在确定有多少种鹰相互共存，以及这些物种之间是如何联系的。研究人员正在使用这些数据来确定岛屿上的鹰群落是通过单一的殖民然后多样化的方式在地球历史上聚集在一起的，还是多个鹰的谱系独立地殖民于同一岛屿。通过比较观察到的横跨海洋岛屿的模式和大陆地区鹰的群落聚集模式，该项目将确定这两种类型的地貌中如何创建群落的差异。该项目是第一个重建全球分布的鸟类群体群落组装模式的项目之一。最后，该团队正在研究来自世界各地的10,000多个鹰标本，以将鹰归入功能生态组，并确定自然历史特征(如典型的猎物类型)，这些特征对于许多较稀有的鹰物种来说是未知的。研究人员正在与德雷克塞尔大学自然科学学院的女性自然科学(WINS)项目合作，让来自弱势背景的女高中生接触STEM领域。该团队正在为所有参与者组织观鹰实地旅行，每年夏天都会有一名WINS学生作为该项目的研究助理参与该项目。该项目还支持西班牙裔美国人少年派领队的早期职业发展。这两名私人助理都是一家大型公共博物馆的研究人员，并在公共宣传活动中传播项目成果。最后，通过确定拥有独特物种的岛屿和地区，保护资源可以更好地用于最需要的地区或物种。重建群落聚集的格局和过程是理解生物群生态和进化的关键。群落可以通过几种方式形成，其中一种预测是，海洋岛屿上的群落是通过聚集(一次扩散后形成物种)聚集在一起的，而大陆群落是通过多个扩散事件聚集在一起的。鹰鹰复合体包括大约180个目前有效的命名分类群(种和亚种)，这些分类群同时出现在大陆和岛屿上。即使在偏远的岛屿上，在相同的生态群落中也发现了多个行为和生态相似但大小不一的鹰复合体，这使得这种鹰复合体成为在全球分布的种群上测试群落组装模式的理想种群。该项目包括四个目标：1)重建天鹰复合体的亚种水平系统发育；2)识别地理分布上有多个天鹰复合体成员重叠的地理区域；3)根据形态检查确定这些鹰的大小和自然历史类别；4)识别天鹰复合体中的群落聚集模式。为了实现这些目标，研究人员正在对基因组进行测序，以利用现有的标本重建综合体内所有目前公认的亚种的系统发育图，为每个鹰-综合体成员创建详细的范围图，并在全球重建这个综合体的社区组装模式。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Although hawks are among the most charismatic bird groups, we know surprisingly little about how species of hawks are related to each other, how their communities have assembled over earths history, and even how many species there are on our planet. In particular, hawks that live on remote islands are poorly known and many are considered members of single widespread species, yet several of the island dwelling hawk populations are sufficiently distinct that they should be considered separate species unique to these islands. Using next generation DNA sequencing, this research is determining how many species of hawks coexist with one another and how the species are related. The researchers are using these data to determine whether the hawk communities on islands assembled over earth’s history via a single colonization followed by diversification or whether multiple hawk lineages independently colonized the same islands. By comparing the observed patterns across oceanic islands to the patterns of community assembly of hawks on mainland regions, this project will identify differences between how communities are created in these two types of landforms. This project is among the first to reconstruct community assembly patterns of a globally distributed bird group. Lastly, the team is examining over 10,000 hawk specimens from around the world to place hawks into functional ecological groups and identify natural history characteristics (such as typical prey types), which are unknown for many of the rarer hawk species. The researchers are partnering with The Women in Natural Sciences (WINS) program at the Academy of Natural Sciences of Drexel University to expose female high school students from disadvantaged backgrounds to STEM fields. The team is coleading hawk-watching field trips for all participants, and each summer a WINS student is working on the project as a research assistant on the project. This project is also supporting the early career development of the lead PI, a Hispanic American. Both PIs are researchers at a large public museum and are disseminating project results at public outreach events. Lastly, by identifying islands and regions harboring unique species, conservation resources can be better directed towards the areas or species in greatest need. Reconstructing the patterns and processes of community assembly are critical for understanding the ecology and evolution of biotas. Communities can be formed in several ways and one prediction is that communities on oceanic islands are assembled via clustering (a single dispersal followed by speciation), whereas continental communities are assembled via multiple dispersal events. The Accipiter hawk complex includes approximately 180 currently valid, named taxa (species and subspecies) that occur on both continental and island land masses. Even on remote islands, multiple behaviorally and ecologically similar, but variably sized Accipiter-complex hawk taxa are found in the same ecological communities making this hawk complex an ideal group for testing community assembly patterns on a globally distributed group. This project includes four objectives: 1) reconstruction of a subspecies level phylogeny of the Accipiter-complex, 2) identification of geographic regions with multiple Accipiter-complex members overlapping in geographic distribution, 3) characterization of size and natural history classes of these hawks based on morphological examination, 4) identification of community assembly patterns in the Accipiter-complex. To accomplish these objectives, the researchers are sequencing genomes to reconstruct a phylogeny for all currently recognized subspecies within the complex using existing specimens, creating detailed range maps for each Accipiter-complex member, and reconstructing community assembly patterns for this complex across the globe.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.