Satellite view of the Negro-Branco moist forests, in Brazil, Venezuela, and Colombia   Northern South America: Eastern Colombia into Venezuela and Brazil Tropical and Subtropical Moist Broadleaf Forests   82,200 square miles (212,900 square kilometers) -- about the size of Utah Vulnerable

· Rivers White and Black
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern
More Photos

Rivers White and Black

The rivers of this ecoregion are as varied as the plants and animals that depend on them. River types include nutrient-rich whitewater rivers, nutrient-poor clearwater rivers, and tannin-stained nutrient-poor blackwater rivers. This area consists of forested lowland plains, with some wide, rolling hills, and low sandstone table mountains.

Special Features

This ecoregion lies along the Rio Negro basin, along the southwestern edge of the Guayana Shield in eastern Colombia, southwestern Venezuela, and northwestern Brazil. Elevations range from 390 to 1,310 feet (120 to 400 m), and annual precipitation is between 80 to 120 inches (2000 to 3000 mm). The landscape is dominated by flooded and non-flooded forests alike, and consists of both vársea forest and igapó forest types, as well as isolated patches of shrub communities and llanos savanna-like meadows. Trees in evergreen lowland forests reach 130 feet (40 m) in height, but low evergreen flooded palm forests grow only half as high. The region is heavily influenced by the numerous rivers and streams, which form the Negro River and Branco River watersheds. The hydrology of the area is complex, with most of the water draining into the Orinoco basin, but some flowing to the Amazon basin. This is also a region of high species endemism, particularly among plants.

	The bearded saki is a heavily furred monkey that lacks a prehensile tail and lives in the upper canopy of mature rain forests. The monkeys travel in troops of up to 25 individuals, and forage for fruit and seeds in the high treetops.

Wild Side

High atop a Virolia tree, a troop of bearded saki monkeys makes its way through the upper branches, eating abundant fruits. In a large hollow tree cavity, a group of spear-nosed bats spend the day resting and fanning their wings to keep cool. In an endemic chiquichiqui palm, a pair of scarlet macaws holds palm nuts in their feet as they open them with their powerful beaks. Clinging to a Costus, or native wild ginger plant, a palm viper sits quietly as a small frog approaches. Hidden in a fallen tree, an endemic grey-legged tinamou calls its eerie cry through the early morning mist. Along the riverâs edge, a tapir and her spotted young cautiously drink water, aware that this is jaguar territory. Two endemic antbirds, the yapacana and grey-bellied, move through the lower canopy in search of small insects.

Cause for Concern

Due to the inaccessibility of this region, the forest remains largely intact. People living in settlements along the rivers practice small-scale agriculture. However, boat traffic brings loggers and merchants into the region--and with them come problems associated with the hunting of large mammals, plant collecting (especially palm nuts and Brazil nuts), and human-induced fires.

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