This course offers a world class opportunity to study the unique Elfin Forest in Nicaragua. This forest is part of the famous Cloud Forests, which are fascinating habitats that are globally endangered. These mountain forests are inherently cool and rainy, representing unique ‘sky islands’ with a high proportion of endemic species, many not even described to science, yet. The course objectives are to document and quantitatively inventory, for the first time, the existing biodiversity of this habitat located at app. 1000m altitude. The Maderas volcano offers a unique altitudinal gradient and mountain top to assess this tropical mountain wilderness, but also human impacts including climate change and invasive species. This course teaches expedition skills, and makes use of the nearby Ometepe field station as our base. The sophisticated field work is based on well-planned individual student research projects, and includes two steep hikes to the Elfin Forest that are physically demanding and require to be in a good health condition (similar to mid-distance running) and being able to sustain two sessions of 2-3 days of continuous field work on the volcano; basic data skills and a good team spirit are essential.