Scientific American 201907

44 Scientific American, July 2019

banana-leafed Ravenala trees crowd out the

sun, their electric blue seed pods dotting the

leaf litter and white sand below. When night

falls, gray mouse lemurs emerge from tree

hollow dens to feed on insects, flowers and

fruit. During the rainy season, pools of water

form where screw pines’ pom-pom-like clus-

ters of long leaves meet their trunks, the base

of each leaf forming a reservoir just large

enough to nurture small schools of tadpoles

to maturity before the puddles dry out every

April. There ring-wearing tree frogs—named

for the bright-white bands that mark each

webby finger—find a perfect spot to nurture

their next generation, high above would-be

predators. Leopard-spotted and no bigger

than a child’s thumb, the frogs lay their eggs

in a sticky clutch above the water and stand

watch for nearly a week, until their offspring

drop into the tiny pool and begin to swim.

At close range, this corner of Mandena feels like you could

get lost in it. But above the canopy reality looms into view. For-

est once stretched to the horizon. What’s left of it is now small-

er than Brooklyn’s Prospect Park—less than a half-hour walk

from end to end, sandwiched between a mine on one side and a

steadily expanding village on the other.

Madagascar broke free of the land that makes up Africa and

India nearly 100 million years ago. Across the eons, evolution in

isolation has given the island unparalleled ecological richness:

Four out of five plants and animals there are found nowhere

else, the sweeping cast of characters in a wide array of highly

specialized symbiotic niches. The country’s 83 species of screw

pine alone serve as breeding grounds for dozens of different

reptiles and amphibians. But the ballet between this particular

tree and frog is now confined to a tiny collection of forest frag-

ments, like the one in Mandena, that are spread along Madagas-

car’s southeastern coast. Two of the three smatterings of forest

where the frog is still found lie inside a concession belonging to

Rio Tinto, one of the largest mining companies in the world.

Rio Tinto came to Madagascar in the 1980s, looking for il -

men ite, a mineral used to make titanium dioxide, which pro-

vides the white pigment found in products ranging from paint

and plastics to toothpaste. Test pits hit pay dirt near Tolagnaro

(Fort Dauphin), at the southeastern tip of the island. The ilmen-

ite deposits that interest the company lie underneath the rem-

nants of dense evergreen forests that once grew on sand dunes

along most of Madagascar’s eastern coast, forming a continu-

ous band covering perhaps 465,000 hectares. Since human col-

onization of the island some 2,000 years ago, these littoral for-

ests, as they are known, have dwindled to at most 10 percent of

their original expanse. As such, Rio Tinto’s concession weaves

through one of the most threatened ecosystems on the planet.

Ordinarily, the discovery of so much buried wealth under-

neath an already vulnerable ecosystem would spell doom for

most of what lives there. But in 2004 executives at Rio Tinto,

which is headquartered in London, flew to the International

Union for Conservation of Nature’s World Conservation Con-

gress in Bangkok, a major gathering of scientists, environmen-

talists, and government and business leaders, to unveil what

amounted to a radical rethinking of mining’s relationship with

the natural world. Going forward, they pledged, the company

would seek not just to limit the environmental damage it caused

but to actively improve the ecology of its most sensitive mine

sites. And it would start with the mining concession in south-

eastern Madagascar.

Conservationists met the proposal with enthusiasm. They had

reason to be optimistic: Rio Tinto and its predecessor had already

been collaborating with scientists from the Missouri Botanical

Garden for more than a decade, funding and conducting botani-

cal surveys and studies of the new species discovered throughout

PRECEDING PAGES: ED K ASHI

Redux Pictures

Rowan Moore Gerety is a reporter and radio producer in

New York City and author of Go Tell the Crocodiles: Chasing

Prosperity in Mozambique (The New Press, 2018). His reporting

trip for this story was paid for with a grant from Mongabay.

IN BRIEF

In 2004 mining company Rio Tinto vowed to

improve the ecology of its most sensitive sites. It

would start in Madagascar, where the company was

working to extract the mineral ilmenite.

Conservationists working in Madagascar, which

is rich in species that are found nowhere else in the

world, partnered with Rio Tinto to help the compa-

ny make good on its pledge.

Eventually Rio Tinto retreated from its promise,

raising questions about whether mining companies

and conservationists can collaborate effectively on

environmental stewardship.

In the

forest

ın

Mandena,

Madagascar,