Rain begins saturating the ground about November, and gradually the water starts to rise. The Paraguay River and tributaries swell and overflow, so that in January, February, and March—in a really full year—only the winding gallery forests called cordilheiras and the round, hummocky forests called capões and the earth that humans have scraped into dikes and mounds are dry land. The rest is damp or muddy or wet or flooded in various degrees. Wading birds, caimans, fish, and semiaquatic mammals like tapirs and capybaras disperse across the flooded land. Animals that like to keep their feet dry— jaguars, ocelots, crab-eating foxes, deer (and often cattle)—crowd into the narrow forests and make do till the waters subside.
In the dry season, roughly May through September, the water withdraws into its riverbeds and shrinks into rounded, puddle-like ponds called baías, and the whole marsh is transformed into a tawny savanna. Wading birds throng the shrinking baías and sloughs, gorging on stranded fish. When the seasonal ponds dry up and the last fish are gone, the birds retreat to the forested rivers and streams.
It's an improbably soggy place for ranching. But since the late 19th century the Pantanal has been given over to immense cattle ranches, called fazendas in Brazil, so lightly placed on the landscape they look more like wildlife refuges than ranches. It's a style of cattle ranching imposed by the sharp extremes of the wet and dry seasons—and that serendipitously has protected this extraordinary ecosystem.
As wetlands all over the world have been degraded and destroyed, the Pantanal, its abundant wildlife, and its distinctive ranching culture have survived into the present relatively intact, insulated by the annual floods and the near-feudal distribution of land. Fiefdoms of half a million acres (202,343 hectares) were once common and still exist today. Bia Rondon doesn't think Santa Sophia's more than 85,000 acres (34,398 hectares) is much to boast of; her grandfather's ranch, Fazenda Rio Negro, once sprawled over 692,000 acres (280,042 hectares).
"You need a lot of land to raise cattle if three-quarters of it is going to be underwater three months out of every year," one Pantaneiro explained. "And you won't bother undertaking extensive alterations—roads and dikes and buildings. The full season's just going to wash them away, if not this year, surely the next. The man of the Pantanal learned early on that he couldn't fight the full."
But the insulation of the full may no longer provide sufficient protection. Industrial soybean and cotton plantations increasingly dominate the highlands north and east of the Pantanal, drizzling damaging sediment and herbicides and fertilizers downstream into the floodplain. Their owners and the multinational corporations they supply exert relentless pressure on the governments of Brazil, Paraguay, and Bolivia to deepen the Paraguay River for oceangoing tankers and to build an all-season highway to speed their goods to market. These big infrastructure projects, many believe, would be catastrophic for the fragile hydraulics of the Pantanal.