Species ranges and diversity patterns in tropical montane birds

热带山区的鸟类比地球上任何其他地区都多。这种高度多样性的一个原因是，随着物种的退出和被其他物种取代，鸟类群落从低地到山顶发生了巨大的变化。这项研究有两个主要举措。首先，我们的目标是提高我们的知识有多少物种出现在热带山区和多样性如何变化沿着山坡。其次，我们将努力理解为什么许多物种仅限于热带山脉斜坡上的一部分海拔范围。换句话说，是什么阻止了低地的鸟类，它们可以飞很长的距离，而不是殖民栖息地只有500米上坡？秘鲁安第斯山脉的马努生物圈保护区和哥斯达黎加的蒙特韦尔德云雾森林被选为这项工作的地点，因为它们是主要的生物多样性“热点”。例如，在马努的一条沿着75公里的样带中，我们可以找到1100种鸟类，比整个北美都多。第一项举措将依靠对物种及其生境的调查，在卫星传感器的帮助下绘制整个景观的多样性模式，卫星传感器可以远程描述大片地区的生境结构。第二项举措将根据物种对不同温度的耐受性，确定物种可能占据的海拔范围。对于那些没有占据生理上可容忍的整个条件范围的物种，我们将研究如何与环境和其他物种，如食物资源和竞争对手的相互作用，而不是决定物种可以生活在哪里。热带山区被视为气候变化将对动植物产生重大影响的地区。世界上超过四分之一的濒危鸟类栖息在这些地区。在下一个世纪，随着气温的升高，许多热带物种将不得不向上游迁移。任何阻止它们殖民新环境的事情都会增加它们灭绝的风险。目前，几乎没有人知道任何热带物种对温度变化的耐受性。物种间的相互作用也可能影响上坡运动，以应对变暖。这项研究将为生物多样性热点地区的许多物种提供这些数据。

Tropical mountains have more bird species than any other region on earth. One reason for this high diversity is that bird communities change dramatically from the lowlands to mountain tops as species drop out and are replaced by others. This research has two major initiatives. First, we aim to improve our knowledge of how many species occur on tropical mountains and how diversity changes along mountainsides. Second, we will strive to understand why many species are restricted to just a portion of the elevation range available on the slopes of tropical mountains. In other words, what prevents lowland birds, which can fly long distances, from colonizing habitats only 500 meters upslope? The Manu Biosphere Reserve in the Andes of Peru and the Monteverde Cloud Forest of Costa Rica were chosen as sites for this work because they are prime biodiversity "hotspots". For example, along a 75-km transect in Manu, we can find 1100 bird species, more than in all of North America. The first initiative will rely upon surveys of species and their habitats to map diversity patterns across the landscape, with the help of satellite sensors that remotely describe habitat structure across large areas. The second initiative will determine the range of elevations that species can potentially occupy based on their tolerance of different temperatures. For species that do not occupy the entire range of conditions that are physiologically tolerable, we will study how interactions with the environment and other species, such as food resources and competitors, may instead determine where species can live. Tropical mountains have been targeted as regions where climate change will have large impacts on plants and animals. More than a quarter of the world's endangered bird species inhabit these regions. Over the next century, many tropical species will have to move upslope as temperatures increase. Anything that prevents them from colonizing new environments will increase their risk of extinction. Currently, almost nothing is known about tolerances of any tropical species to changing temperatures. Species interactions could also affect upslope movements in response to warming. This research will provide these data for many species in biodiversity hotspots.