The Pantanal, thought to be the largest, undeveloped wetland complex on Earth, covers almost 70,000 square miles at the junction of Brazil, Bolivia and Paraguay. A desert landscape as recently as 13,000 years ago, this flat ecosystem is now a mosaic of meandering rivers, seasonal lakes, oxbows, sloughs, grasslands, marsh and woodlands. During the wet season, which lasts from October into April, 80% of the Pantanal (Portuguese for wetland) is flooded by its primary streams, which drain the adjacent highlands and distant mountains. With the onset of the dry season, the flora and fauna undergo a dramatic change, augmenting the tremendous array of life in the Pantanal.
Rivaling the diversity of the Amazon Rainforest, this wetland is home to over 700 species of birds, including greater rheas, toucans, macaws, parrots, giant black eagles and, of course, a wide variety of waders. Resident mammals include jaguars, ocelots, maned wolves, giant otters, Brazilian tapirs, howler and capuchin monkeys, giant anteaters and capybaras, the largest rodents on Earth. Anacondas and caimans are among the Pantanal's many reptiles and almost 300 species of fish inhabit its many lakes, streams and seasonal wetlands.
Though "undeveloped," the Pantanal has been used for cattle ranching and is threatened by a variety of human activities. Pollution from upstream mines, human settlements and agricultural areas is perhaps the major threat though deforestation, poaching and unregulated tourism all take a toll. Most recently, plans to divert water from this fragile ecosystem tempt disaster.
