Ecuador is one of the smaller countries in South America (ca. 285,000 sq. km.) yet contains an enormous diversity of habitats with very high biodiversity. The country has a relatively small population (around 14 million) of which four million are located in the cities of Guayaquil and the capital Quito. Plaza San Francisco, QuitoThe country is bisected by the equator, from which it derives its name, and is divided from north to south by the Andes mountains. The highest point in the country, Volcano Chimborazo, is 6310 m but there are many other towering volcanic peaks andVolcan Sumaco the capital Quito is the second highest capital city in the world at 2800 m. Nine of the country's 55 volcanos are active and a similar number are classified as potentially active. The habitats in Ecuador range from the hot and humid lowland rain forest of Amazonia to the east of the Andes,Rain Forest Tree Platform Napo Wildlife Centre through sub-tropical cloud forest on the eastern slopes of the mountains to the Paramo treelessParamo region at higher altitudes and finally to the tundra regions on the mountain tops. This diversity of habitats has led to opportunites for an amazing diversity of plants and animals to thrive in Ecuador. Ecuador is perhaps the most biodiverse region on earth with 1600 species of birds and 317 species of mammals. The rivers flowing from the peaks of the Andes join to form major rivers, such as the Rio Napo which eventually join with other tributaries to form the Amazon River. These rivers are known as white water rivers while other flooded areas containing the breakdown products of plant material are referred to as blackwaters. Significant seasonal changes in water levels mean that even white rivers such as the Rio Napo develop sandbanks and can be difficult to navigate at times.