Partido Coronel Rosales, Provincia de Buenos Aires, Argentina Photograph by Tiziana Prada   Southern South America: Southeastern Argentina Temperate Grasslands, Savannas, and Shrublands   126,300 square miles (327,000 square kilometers) -- about the size of New Mexico Critical/Endangered

· A Sea of Grass
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern
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A Sea of Grass

The Semi-Arid Pampas ecoregion is primarily temperate grasslands, mixed with deciduous thorn woodlands in the western portion. Like the Great Plains of North America, this ecoregion is a broad, flat plain, lacking trees except in drainage areas along rivers. Dunes form in the drier areas, while ponds and lakes are common in the wetter northern areas.

Special Features

These are some of South America’s richest grasslands. The land is dominated by tuft grasses, scattered trees and interspersed with mesquite, jarilla, and ephedra shrubs. This ecoregion is home to a number of endemic species, including the band-tailed earthcreeper, white-throated cachalote, and tuco-tuco.

	Male lesser rheas are so protective of their chicks that they will defend them against passing airplanes and horseback riders. South American cowboys known as gauchos often keep dogs with them to scare off the aggressive rheas.

Wild Side

The Semi-Arid Pampas support a diversity of wildlife. Greater and lesser rheas forage among the tall grasses, their presence given away by their long ostrich-like necks. Mixed flocks of great pampas-finches, long-tailed reed-finches, and lesser red-breasted meadowlarks feed on abundant grass seeds and occasional insects. The melodious whistle of a red-winged tinamou attracts the attention of a wary pampas cat, whose long gray undercoat and black-striped legs make it nearly invisible among the mesquite and bunchgrass. A llama-like guanaco forages near a small pond, where a great grebe dives among the cattails for crustaceans and aquatic insects. The striking bright-yellow nape of the saffron-cowled blackbird stands out as the bird sways on a grassy perch. Several threatened plants are found here, including the legume Astragalus and the purple iris Cypella wolffhuegeli.

Cause for Concern

The pampas provide one of the richest grazing areas in the world and have been under human cultivation since the 17th century. Thus, the ecoregion has been severely affected by domestic livestock and farming. Considered one of Earth’s most endangered habitats, this once-vast "sea of grass" has only a few true remnant patches left. The loss of habitat has made the ecoregion less hospitable for migrating birds. The Eskimo curlew and several other migrant birds have disappeared from here altogether.

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