Economic management has also paid off. Since the purchase of a large freezer boat, residents have tripled their income by selling premium fish directly to buyers downstream. A growing ecotourism business generates additional cash, along with selective logging in designated areas of the reserve.
The standard of living in is now higher than most areas of rural Brazil, the infant mortality rate is half what it was in 1994, and wildlife populations are flourishing.
But Ayres knew that if the region's amazing biodiversity was to be safeguarded, they would have to increase monitoring: Each agent from IBAMA, the Brazilian environmental agency, must police about 30,000 square miles (77699.6 square kilometers) of forest.
So they built a network of floating stations outfitted with radios, and trained over 100 volunteer wardens. The result: hunting, poaching, and illegal logging is a much smaller problem than in traditional reserves.
"Mamirauá is a refuge for animals that are exploited in other areas," said Miguel Pinedo-Vasquez, an ecologist at Columbia University's Center for Environmental Research and Conservation who brainstormed with Ayres on Mamirauá's original management plan 15 years ago.
And those animals include over 300 bird species, about 50 types of mammals, 400 species of fish, plus innumerable plants and treesand Ayres says there's still much that remains undiscovered.
Ayres: Saving His "Neighborhood"
Ayres discovered his direction at the age of 19, while still a college student. On a research visit to German zoos, he glimpsed his first uakari and saki monkeys, species indigenous to Brazil.
Although he grew up in Belen, near the mouth of the Amazon, he had never seen the monkeys in the wildand realized that almost nothing was known about them.
In 1977, Ayres moved into the Amazon interior to study them. He quickly accomplished what many biologists dream of, discovering not one, but two new species: the black squirrel monkey and the Rio Maues marmoset. Ayres' primatology studies triggered his conservation work. A year into his research, he petitioned the government to protect the habitat of the white uakari. Mamirauá Ecological Station was born, and his vision for the region has continued to expand since.
Citing studies that animals from manatees to jaguars migrate over large areas to find food or mate, Ayres lobbied for conservation of a larger tract of rain forest.
In 1997, the Brazilian government created the Amana Sustainable Development Reserve, connecting Jaú National Park and Mamirauá. It created a 22,000 square mile (56979.7 square kilometer) swath of unbroken, protected habitatan area larger than Costa Ricacalled the Central Amazonian Corridor.
Vasquez attributes Ayres' conservation coup to the fact that he is a native Amazonian. "He grew up there, he knows the ecosystem, and he understands the social landscape. He's managed to work with local people because he's from thereand he's respected by everyone: local fishermen, big ranchers, even the president of Brazil."
Ayres still dreams a bigger dream: to see sustainable reserves linked into wildlife corridors across the Amazon, using Mamirauá as a model. In 1997 he designed a proposal for five ecological corridors in the Amazon and two more along the Atlantic coast.
"If we had 20 more Marcios, we could save the entire Amazon," said Taber.
National Geographic Today, 7 p.m. ET/PT in the United States, is a daily news journal available only on the National Geographic Channel. Click here to learn more about it.
Got a high-speed modem? Watch National Geographic Today in streaming video.
SOURCES AND RELATED WEB SITES