Mt. Roraima, Guyana/Venezuela Photograph by Smithsonian/WWF   South America: Venezuela, Guyana, Suriname, and Brazil Tropical and Subtropical Moist Broadleaf Forests   18,800 square miles (48,800 square kilometers) -- about twice the size of Vermont Relatively Stable/Intact

· Spectacular Slopes
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern
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Spectacular Slopes

The Tepuis ecoregion is named for its most famous feature--isolated mountains with dramatic cliffs rising out of the forest, topped with flat summits covered with an amazing array of species. Some species may be found on a single mountaintop here and nowhere else on Earth. Each mountain, called a tepui, is home to a different set of species and features. But the ecoregion as a whole is known for the wild diversity on these spectacular slopes: waterfalls, birds, orchids, insect-eating plants, monkeys, snakes, iguanas, and more.

Special Features

As the mountains that make up the Tepuis ecoregion rise from the Amazonian forests, the vegetation changes along the steep slopes. Tall trees cover the lower slopes, while only small, hardy plants can survive in tiny cracks and crevices in the upper slopes of the cliffs. Each summit is unique, with a variety of habitats that include tall and dwarf forests, open savannas, and rocky crevices. There is an extraordinary richness of species on these isolated mountaintops. Of the more than 2,300 vascular plant species found in this ecoregion, 33 percent are endemic. Waterfalls are common in the ecoregion and include the world’s largest: Angel Falls.

	The venomous fer-de-lance is one of a group of snakes called pit vipers--snakes equipped with special heat-sensing pits that detect the infrared radiation given off by "warm-blooded" animals. The pits make the fer-de-lance a deadly predator that can detect its prey even in the darkest night.

Wild Side

Birds such as a buff-breasted sabrewing and tepui goldenthroat flit up and down a cliff face, visiting the flowers of orchids, bromeliads, "heath-like" shrubs, and creeping Clusia, which cling to the rocks. In the lowland forests, troops of black uakari and weeper capuchin monkeys patrol the upper canopy for fruits and insects. The call of an endemic tepui tinamou bursts out from the forest floor below, startling a nearby long-tailed weasel, which runs for cover. Squawks from above signal the passing of endemic tepui parrotlets and fiery-throated parakeets. An endemic mouse opossum prowls the canopy at night in search of insects and fruits. In a patch of bunchgrass, the fer-de-lance pit viper coils its body to strike at a guinea pig, while in the forest nearby, the endemic tepui antpitta follows a group of leaf-cutter ants along the ground. An unwary climbing rat is caught in the coils of a boa constrictor, as lizards called tegus sun themselves on a rocky outcropping.

Cause for Concern

Illegal gold and diamond mining on the mountains’ lower slopes threaten both the vegetation and the structure of the Tepuis. However, due to the inaccessibility of the steep slopes and high summits of the Tepuis, much of the natural habitat remains intact. Humaninduced fires at the base of the mountains have spread to the upper slopes and even the summits of some mountains. Because of the region’s poor soils, plant recovery from these threats is slow. Hikers and campers visiting the summits of the Tepuis have trampled vegetation, stripped woody plants for firewood, and left litter behind.

For more information on this ecoregion, go to the World Wildlife Fund Scientific Report.