Argentina Photograph by Alejandro Serrat   Southern South America: Eastern Argentina Flooded Grasslands and Savannas   15,000 square miles (38,900 square kilometers) -- about twice the size of New Jersey Critical/Endangered

· Hanging By a Thread
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern
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Hanging By a Thread

Patches of flooded grassland line the southern Paraná River Valley from Buenos Aires north to Resistencia. This ecoregion was originally one of the most extensive mosaics of riverine and wetland habitat in South America, but it now contains the majority of the human population of Argentina. As a result, the region has been largely converted to agricultural, industrial, and residential uses. Isolated tracts of remaining habitat cling to the edge of the river in areas where development cannot reach.

Special Features

Patches of wooded shrubs and low thickets grow in the remnants of this ecoregion, and numerous palms stretch toward the sky. Birds flutter through the grasslands, including black-headed ducks, brown-and-yellow marshbirds, great grebes, black-necked swans, and whistling herons. To the north, the more humid Chacoan area is filled with more tropical species such as ocelots, cougars, black howler monkeys, parrots, and toucans. Although wildlife is significantly less abundant than it once was, many unique species can still be found.

	The capybara, an animal that lives in this region, is the world’s largest rodent. This mammal can grow to be more than 154 pounds (70 kg) and its partially webbed feet help to make it an excellent swimmer.

Wild Side

Along the shore of the Paraná River, a bright pink Chilean flamingo uses its curved bill like a sieve to strain its food from the water. Nearby, a nutria--a large rodent known also as a coypu--emerges from its burrow in the riverbank to nibble on aquatic plants. Another herbivore, the marsh deer, grazes on leaves and grasses. The large feet of these deer have an elastic membrane between the hooves, which may help keep the deer from sinking in the mud while they graze. A zorro pampa, a type of fox, trots through a patch of reeds, sending a group of dot-winged crakes fluttering into the sky. A pod of La Plata river dolphins--one of the world’s smallest cetacean species--swims north, passing a lobito comun, a type of otter, on their way to the more humid Chacoan area. As the dolphins swim north, vegetation along the shore becomes denser. An ocelot watches them pass, one paw hanging from the gnarled branch of a fallen tree. Color splashes through the trees as a blue-crowned parakeet takes flight. A South American alligator, or yacaré, slips into the river and disappears beneath the jade surface.

Cause for Concern

Agriculture, industry, and urban development push this region into an increasingly narrow thread along the river, especially in the south. The Paraná River flows like an aquatic highway from Buenos Aires to Resistencia, and settlements occur along the length of the river. Water diversion, channelization, and draining have altered the natural flow and critical flooding cycles. Erosion and wastewater pollution are also threats.

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