Species ranges and diversity patterns in tropical montane birds

热带山区的鸟类种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，随着物种的消失和被其他物种取代，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的倡议。首先，我们的目标是提高我们对热带山区有多少物种以及多样性如何沿着山坡变化的认识。其次，我们将努力理解为什么许多物种只局限于热带山脉斜坡上可用海拔范围的一部分。换句话说，是什么阻止了可以长距离飞行的低地鸟类在只有500米高的上坡栖息地定居？秘鲁安第斯山脉的Manu生物圈保护区和哥斯达黎加的Monteverde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，沿着马努岛75公里的样带，我们可以发现1100种鸟类，比整个北美都多。第一项计划将依靠对物种及其栖息地的调查来绘制整个景观的多样性模式，并借助卫星传感器远程描述大面积的栖息地结构。第二项倡议将根据物种对不同温度的耐受性来确定它们可能占据的海拔范围。对于那些没有占据生理上可容忍的全部条件范围的物种，我们将研究与环境和其他物种（如食物资源和竞争对手）的相互作用如何决定物种的生存环境。热带山区已成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。在下个世纪，随着气温的升高，许多热带物种将不得不向上坡迁移。任何阻止它们在新环境中殖民的因素都会增加它们灭绝的风险。目前，人们对任何热带物种对温度变化的耐受性几乎一无所知。物种间的相互作用也会影响上坡运动以应对气候变暖。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.