The Andes is a mountain range in South America that spreads on 7,500 km and crosses seven countries: Peru, Venezuela, Ecuador, Colombia, Argentina, Bolivia and Chile. It covers 33% of the Andean countries and gathers a great number of mountain chains that are linked to one another by orographic knots (high-altitude plateaus). The Andes has three climatic zones: the Tropical Andes, Wet Andes and Dry Andes. With this climatic variations, resides over 1,700 types of birds, 400 species of fish, 600 different species of mammals. Its flora is composed of 30,000 species of endemic plants.