Researcher hears a cry for help from rare silky sifakas

MAROJEJY NATIONAL PARK, Madagascar — Since daybreak he has been scanning the treetops for the creatures that move as if by pogo stick and look as if they wear white fur coats and big, black, round sunglasses.

It is after 2 p.m. and the dense, hilly rain forest has yet to give primatologist Erik Patel a glimpse of Propithecus candidus, the rare lemur known as the silky sifaka. It is one of the world's 25 most-endangered primates. Fewer than 1,000 silky sifakas are thought to exist, all of them in this rugged patch of northeast Madagascar.

Finally, a guide working with him spots a flash of white deep in a ravine. Patel skitters and slides down the slope, where he hears a familiar sound: the sneeze-like "zzuss" call the animals emit when alarmed.

"It's Pink Face," he says, wiping sweat from his forehead. "I know it's him."

Patel, 35, is the planet's foremost expert on the silky sifaka. Over the past four years, he has spent 14 ½ months camping in this forest. He is back for a few weeks to observe Pink Face and the five others in this lemur community. He hopes new data will shed more light on how the animals communicate.

And he feels a sense of urgency. Despite an increase in conservation efforts, no one knows how much longer the silky sifakas can survive persistent hunting and deforestation.

No one can mistake these animals for any other kind of lemur. Only the silky sifakas have fluffy white fur covering their body except for the face, which is slate-gray or pinkish. Their eyes are reddish-orange.

They have been dubbed "flying angels" for the way they appear to soar from tree to tree. They use their powerful legs and finger-like toes to grasp a tree trunk or branch and quickly push off to the next one, up to 10 feet away.

Lemurs have been eating leaves and exploring forest canopy for perhaps 50 million years.

How they got here remains a mystery. Madagascar, along with India, split off from Africa about 125 million years ago, and parted ways from India 88 million years ago — before lemurs existed.

The island's long isolation meant that most of its plants and animals evolved separately from the wider world. Biologists estimate that eight in 10 of its species — plants as well as animals — are found nowhere else. People arrived 2,000 years ago, likely from Indonesia.

The most striking examples of the island's species diversity may be the lemurs.

Taxonomists group them into 70 species and subspecies (humans are known to have driven 17 species to extinction), and all occur naturally only in this country.

The study of lemurs is relatively young, particularly when it comes to species found in forbidding terrain, and few live in tougher territory for researchers than the mountain-dwelling silky sifaka.

Sifakas are a large category of lemurs. They resemble a cross between a bear, a monkey and a raccoon.

Patel's team documented how sifakas spent their time (resting nearly half of it, then foraging for food or playing and grooming), the home range of the study group (the equivalent of 83 football fields) and the distance they typically covered in a day (four-tenths of a mile). Scent markings left by males and females were painstakingly recorded. The result was the first documented behavior known as "totem-tree" scent marking in primates — the repeated marking of particular trees mainly by males apparently competing for female attention.

Patel also made the most complete audio recordings of lemurs in the wild.

They are "talkative," Patel says, and he has amassed a catalog of 600 zzuss calls alone.

By the time he thinks he hears Pink Face, Patel has a lot riding on having a productive, successful trip.

The Cornell doctoral candidate has visited the busy market in Sambava, using a mix of grant money and his cash to load up supplies.

He has hired 14 porters for $4 a day to carry his recording gear, laptop computer, clothes and supplies on their backs or bamboo poles. They walk through two dusty villages, past countryside denuded by "slash and burn" farming, into the park's dense forest and up the mountain.

At Camp 2, which now has four simple bungalows, a few guides will earn $5 a day to help track the animals. The best, Nestor Randrianasy, says the lemurs speak to him in his dreams. He was the one who found them in the ravine.

"Pink Face is his usual self, alarm-calling at nothing, roaring at birds that aren't there" Patel says. He points out Black Hands, a 3-year-old with curious eyes. "I knew BH when she was this big," he says, holding his hands a foot apart. "She's a big girl now, acting like a typical juvenile, falling out of trees."

Through the dense vegetation he spies Antenna Female (named for the radio collar she once had), Black Cap (for the coloration atop his head) and Black Face Pink Hands (a second female), or BP. But he is most interested in a sixth silky he cannot find, a young one born in June 2004.

Infant mortality is high, an additional danger to their survival as a species. Since there may be fewer than a thousand left — all in the wild, none in zoos — every one counts.

The next day, Patel sees the infant. Relieved, he can focus on his primary mission: to collect soft "hum" and "mum" calls thought to be "we're about to move" sounds for analysis.

Patel's $5,000 worth of equipment includes a directional microphone, a grip for the microphone and a digital recorder. Even so, he needs to get within 30 feet of the sifakas, and without too much background noise.

One day is lost when the animals never venture far from a raging river. Early the next morning, though, he captures clear mums from Pink Face and three others.

Moments later, the group shoots up into the canopy for a snooze, something they do five times a day for anywhere from 15 minutes to three hours.

Fifty feet below, Patel sits on a wet log, staring up with binoculars in one hand, his microphone in the other. The sifakas show no movement. Patel opens a bag of cookies and waits.

Two hours later, a few minutes after 12:30, something happens.

BP rapidly descends a tree like a firefighter sliding down a firehouse pole. She parks herself on a branch about 15 feet off the ground and 20 feet from Patel. She looks around and scratches absentmindedly. All the while, she goes "mum, mum, mum."

Patel records every sound.

In Madagascar, human pressures continue to threaten endangered lemurs, even in national parks. Patel has documented as well the threats to silky sifakas, mainly from people. From villagers outside the park he learned that Madagascar's well-to-do enjoyed the taste of lemurs as a delicacy or "picnic food" and hired unemployed villagers to hunt them.

"All you need is a few dedicated hunters, and they could be gone in no time," says Russell A. Mittermeier, president of Conservation International. With donors and Madagascar officials, he is exploring new ways to preserve the species, whose only natural predator is the fossa, a mongoose-like mammal.

A few months ago, a hunter was caught near here with 28 dead lemurs in bags, two of them bone-white silky sifakas.

But the presence of a scientist in the forest may make hunters think twice, says Patricia Wright director of the Institute for the Conservation of Tropical Environments at the State University of New York, Stony Brook. "They're scared to do it if there is a researcher there," she says.

Even more recently, illegal logging of rosewood trees for export to China has expanded inside Marojejy's park boundaries, an ominous development in a country where "slash and burn" agriculture has destroyed 85 percent of indigenous forest. Subsistence farmers clear land to grow rice.

Patel tells impoverished villagers that ecotourism can help them economically. To encourage tourism, he produced a poster about the silky sifaka for the park and, when in the forest, helps European and American visitors spot the elusive lemurs, even if it disrupts his research.

The problem, Patel says, is that there are too few patrols or dedicated park employees. Soon, Patel and geneticist Ed Louis will search for silky sifakas outside Marojejy and an adjacent nature reserve. The goal is to document any sightings in hope of creating new protected areas — something Madagascar's president, Marc Ravalomanana, has committed to doing around this island nation rich in biodiversity.

Patel says he has no idea how many silky sifakas they may find, "but we are sure that they are being hunted and are living in disturbed habitats."

As for capturing several and putting them in zoos to ensure the species' survival, Wright is unsure that is a viable alternative.

"We don't know whether they would survive or not," she says, and no one wants to take that chance, yet. But if the hunting and habitat disturbance continue, "we have to think differently."