Gran Chaco, Bolivia & Paraguay

Jaguar Family Photo
A jaguar family plods through Kaa Iya National Park, Bolivia, near the Isoso Station of the Santa Cruz-Puerto Suarez Gas Pipeline. WCS conservationists confirm that the mother, nicknamed Kaaiyana, has lived in the area for six years.
© Daniel Alarcon
Gran Chaco, Bolivia Photo
The Gran Chaco is the largest dry forest in South America and the continent’s most extensive forested region after Amazonia.
©R. Montano/WCS

The Gran Chaco is the largest dry forest in South America and the continent’s most extensive forested region after Amazonia. Spanning close to 400,000 square miles, it extends across parts of ArgentinaParaguay, Bolivia, and Brazil, where it connects with the Pantanal, the world’s largest wetland. Gran Chaco contains three distinct subregions with varying climates: the Humid Chaco, Dry Chaco, and Montane Chaco. These diverse environments include plains, swamps, seasonally flooded savannas, salt flats, and a great variety of forests and scrublands. The Gran Chaco provides good habitat for the Chacoan peccary, as well as the white-lipped and collared peccaries, the Chacoan hare, 10 species of armadillo, tapirs, guanacos, and jaguars. Additionally, the region is a center of cultural diversity. However, its once numerous nomadic hunters, gatherers and fishermen, together with a group of farmers who have long called Gran Chaco home, are now severely threatened by habitat degradation and loss of traditional land rights.

Fast Facts

  • The Gran Chaco harbors approximately 3,400 plant species, 500 bird species, 150 mammal species, 120 reptile species, and 100 amphibian species.
  • The Gran Chaco is one of the hottest places on the South American continent.
  • The Chacoan peccary first became known to science in the 1970s.
  • The Gran Chaco was the scene of a brutal territorial war between Paraguay and Bolivia (1932–1935) that left approximately 100,000 people dead.


For more than a century, the Gran Chaco has been environmentally degraded, and gradually losing its natural wealth. Poorly planned natural resource extraction and extensive livestock operations are largely to blame. Additionally, in more recent years, new challenges to conserving the region’s unique biodiversity have arisen. These include poorly planned natural gas and infrastructure development  and groundwater tapping for irrigation projects in Bolivia, along with land prospecting in Paraguay, particularly by Brazilian and Uruguayan ranchers.

WCS Responds

In 1995, WCS supported an initiative by the Isoceño Guaraní people that led the Bolivian government to create the Kaa Iya del Gran Chaco National Park in Bolivia's Santa Cruz Province. Covering 13,000 square miles, Kaa Iya is the largest protected tropical dry forest in the world. WCS is promoting the integration of the protected area, indigenous community lands, and local government territorial plans, including important wetland areas. We are also working to improve rangeland management for livestock and wildlife such as guanacos and jaguars. Since we began working in Bolivia's Gran Chaco, we have mentored more than 120 Bolivian conservation professionals and trained more than 23 indigenous wildlife monitors.

In 2010, WCS started working as part of a consortium of Paraguayan and international partners to conserve the Paraguayan Chaco. Given that the vast majority of land in Paraguay is privately owned, our strategy to conserve the Chaco’s biodiversity focuses on forming partnerships with ranchers and landowners to safeguard the region’s wildlife and ecosystems. For example, we promote sustainable livestock management practices, encourage the establishment of private reserves, and promote alternative economic activities, such as the sustainable marketing of non-timber forest products. Additionally, in Bolivia, Paraguay, and Brazil we are working to save jaguars by conducting workshops with ranchers, veterinarians and governmental bodies, to evaluate current ranching practices and promote more wildlife-friendly cattle management. Given the complex challenges and myriad of players in the Gran Chaco, working with key stakeholders across these three countries is crucial for conserving one of South America’s last wild places.

WCS Projects

Gas Pipeline from Bolivia to Brazil

WCS and the Capitanía de Alto y Bajo Isoso, the indigenous organization representing the Guaraní people of Bolivia’s Chaco, have worked as partners for more than 15 years. The partnership has helped both institutions deal with challenges arising from the rapid expansion of Bolivia’s hydrocarbon industry into this fragile landscape.

From the Newsroom

Bolivia: Land of Giant Anteaters and Fairy ArmadillosJuly 23, 2013

A newly published WCS database shows the range of 116 species of Bolivian mammals, from the obscure “Count Branickii’s terrible mouse” to the mighty jaguar. The database will help shape future conservation decisions for some of South America’s most threatened and charismatic wildlife.

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