Cauca River Valley, Valle, Columbia Photograph by Carl Downing   South America: In the Cauca Valley of western Colombia Tropical and Subtropical Dry Broadleaf Forests   2,800 square miles (7,300 square kilometers) -- about the size of Delaware and Rhode Island combined Critical/Endangered

· Down by the Riverside
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern
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Down by the Riverside

This ecoregion consists of a long and narrow strip of dry forests along the Cauca River in western Colombia. In a valley surrounded by the majestic northern Andes Mountains, the rich mosaic of habitats here include open woodland, dry forest, riparian forest, arid scrub, and wetlands. On either side of the valley, the dry forests give way to moist montane forests along the slopes of the central and western Andes Mountains. Much of the landscape has been altered by agriculture and other human activities, but the patches of natural vegetation that remain provide important habitat for animals such as three-toed sloths and long-tailed weasels.

Special Features

The vegetation in this area was historically deciduous dry forest, mixed with arid scrubland and evergreen dry forest along the river and its tributaries. Today, native vegetation occurs in patches and in various states of successional development. Common pioneer plants include Cecropia, Croton, and Inga. The Sinso Lagoon and surrounding forests occur in an ancient oxbow of the Cauca River and now host many of the once common species. This area also hosts a number of endemic species.

	Sloths use more than 200 species of trees, but they are most often spotted in Cecropia trees. This is because Cecropia is a common successional species in this ecoregion, and the sloth’s green, algae-covered fur stands out against the pale undersides of Cecropia leaves.

Wild Side

In a dry deciduous forest overlooking the Cauca River, a three-toed sloth moves slowly through the crown of a Cecropia tree as it munches on the tree’s large, frilled leaves. Moving along the canopy of an Inga tree and on the ground below, a large group of coatis--small raccoon-like rodents--pick and prod at dead tree stumps, bromeliads, and leaf litter for insects, bird eggs, and small prey. In a neatly excavated burrow nearby, a naked-tailed armadillo sleeps the day away, while a group of red brocket deer are spooked by an approaching ocelot. A long-tailed weasel trots across the open dirt in search of ground-nesting birds and rodents. The Cauca Valley also teems with birds. A large black antbird picks through the understory as it searches for ants and small insects, an endemic Cauca guan scratches at the dirt and leaves for its insect prey, and a spot-breasted woodpecker taps on a hollow tree, echoing a rhythmic tune that will attract mates and warn other males of its territorial boundaries.

Cause for Concern

The beauty and biodiversity of the Cauca Valley have attracted humans for centuries. The landscape is now dominated by crops of coffee, maize, bananas, sugarcane, cassava, citrus fruits, and avocados. The city of Cali is in the ecoregion, and many other cities and towns line the Cauca River here as well. Both urban sprawl and agricultural expansion have created a patchwork of natural habitats here that are vulnerable to the invasion of introduced grass species. Overhunting and the illegal collection of wildlife for the pet trade also take their toll on certain native species.

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