Venezuela is the 6th largest country in South America, with a 2,800 kilometer long coastline. It is a large country and 72 nearby islands are also part of it. Venezuela is divided into three geographical regions: Cordillera, Llanos, and the Guiana Highlands. The Cordillera is a highly mountainous region in Northwest Venezuela. The Llanos is an enormous area of flat land in central Venezuela. The Guiana Highlands covers half of Venezuela and is an upland area of lush vegetation. The Orinoco River is the primary drainage channel of Venezuela and flows 2,560 kilometers. The national average temperature is 82ºF, with 90% of the country being above 75ºF. Altitude is the only cause of regional variation in temperature, with altitudinal differences of 1,524 meters between the cities of Mérida and Maracaibo. Vegetation also varies hugely with altitude, where below 457 meters, the climate is mostly tropical. Above 457 meters, the climate is primarily subtropical. Above 1,524 meters, there is mostly mountain vegetation; above 3,048 meters, there are only a few species of alpine shrubs that are adapted for the harsher climate. Venezuela is rich in animal life, however most of the species of animals that live there are also found throughout South America. Some animals that call it home are monkeys, bears, deer, jaguars, pumas, coral snakes, striped rattlesnakes, boa constrictors, anacondas, boto dolphins, inia dolphins, and pink porpoises. While many of these species are also found outside of Venezuela, that does not change the fact that Venezuela is highly diverse in animal life. Venezuela also has 1,300 species of birds—42% of all South American species of birds and 14% of all species of birds worldwide. Overall, Venezuela has an incredibly diverse climate for a very small country and a visitor can see all the four types of climate as well as the many local animals.