Guarding the Chaco's Nest.

• Author: Darsie, Jann

A NEW GENERATION OF CONSERVATIONISTS IN PARAGUAY IS EMERGING AS THE DEFENDERS OF A PARK THAT CONTAINS A RARE MIXTURE OF ENDEMIC AND ENDANGERED SPECIES

When Maria de los Milagros Lencina Chaves and Rocio Barreto graduated from the National University of Paraguay, like most graduates everywhere, they were job hunting. They both studied science--Chaves, forestry and Barreto, biology--but neither of these young women imagined that their first professional assignment would be working on a collaborative, international investigation of a protected area of the Paraguayan Chaco.

Defensores del Chaco National Park (Defensores) forms a large part of the 250,000-square-miles known as the "Grand Chaco," which extends into neighboring Bolivia to the north and Argentina to the south. The Paraguayan Chaco--its wetlands, dry forest, thorny scrub, and seasonal rivers and streams define the heart of one of South America's last great wilderness areas. Actually, the Chaco is divided into "humid" and "dry." The former is the southernmost portion, beginning just north of the Paraguay River, near the capital city of Asuncion, where the Trans-Chaco highway also originates. Traveling along this mostly lonely road, the landscape slowly changes from tropical foliage--and flocks of graceful, pink roseate spoonbills--to dry scrub. As the palm trees vanish, so does the paved road, at the Mennonite settlement of Filadelfia. This section is officially the "dry Chaco."

We travel northwest, dust flying behind the four-wheel-drive truck loaded with provisions for the expedition. Night falls and so does the rain, despite the fact that our work has been scheduled to coincide with the height of the dry season. The truck slows, and the driver, Luis Moran, a technician with the National Museum of Natural History, begins the laborious task of keeping our sliding vehicle on the road. More than seventeen hours pass in our journey to the remote protected area of Defensores, and Moran breaks the monotony of the trip with tales of his father's adventures as a hero in the Chaco War. This war was fought from 1932 to 1935 as both Bolivia and Paraguay struggled to gain and retain control of the Chaco, and access to a navigable passage to the Atlantic. Paraguay succeeded in not losing territory, but paid for its defense with great human loss.

Defensores is a fragile and endangered ecosystem. The Paraguayan government has classified the area as its number one priority for conservation, and it has been declared a World Heritage Site by UNESCO. Both the World Bank and the Biodiversity Support Program, a consortium of conservation organizations addressing biodiversity loss, term it vulnerable and of the highest regional biological value. The rich mixture of life forms from the Amazon in the north, the pampas and...