Species ranges, diversity and life history of Neotropical montane birds

点击翻译按钮获取中文摘要

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. My research aims 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? Additionally, my research builds upon a long-term monitoring database to evaluate the stability of tropical bird populations, supplying crucial information to determine whether such populations are growing or in decline. This research will be carried out in three sites across the Neotropics: the Manu Biosphere Reserve in the Andes of Peru, Tatama National Park in central Colombia, and the Monteverde Cloud Forest of Costa Rica. These areas represent 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 test alternative hypotheses regarding how the interactions of birds with other species (e.g., competitors, mutualists, food resources) or the ability of birds to tolerate extreme environmental conditions (e.g., cold temperatures at high altitudes) determine where species live on a mountainside. The second initiative will examine data from banded birds, which have been recaptured and monitored across years, to estimate how long tropical species live and how populations are changing. It will also apply new technologies to understand how species will respond to novel environments. Tropical mountains have been targeted as regions where climate change will have disproportionately 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 could be forced to move upslope as temperatures increase. Anything that prevents them from colonizing new environments will increase their risk of extinction. Currently, we know very little about how tropical species will respond to changing temperatures or whether species interactions could affect upslope movements in response to warming. This research will provide these data and fill important knowledge gaps for many tropical bird species while improving our conservation strategies for these biodiversity hotspots.