Monday, March 31, 2014

For the love of lemurs and Madagascar

The IMAX movie “Island of Lemurs: Madagascar” opens nationwide on April 4, including Atlanta's Fernbank Museum of Natural History. Mouse lemurs, above, are among those featured in the film about the island, a bio-diversity hotspot.  (Photo by Frank Vassen)

By Carol Clark

“I smell props,” says Sarah Zohdy, a biologist in Emory’s Department of Environmental Sciences and the Rollins School of Public Health. She looks skyward, scanning a tangle of thick Tarzan vines, tree branches and leaves that weave the dense rainforest canopy 100 feet above.

“Do you smell that?” Zohdy asks a new arrival to Madagascar’s Ranomafana National Park. “They have a scent like maple syrup.”

Then, whoosh! A wide-eyed, fur-covered acrobat, mostly arms, legs and tail, leaps out of one clump of leaves and disappears into another.

“Props!” Zohdy confirms, smiling at the comical effect of the creature. “Their legs are crazy long for their bodies.”

Propithecus edwardsi
Propithecus edwardsi, more commonly known as a sifaka, is one of nearly a hundred species of lemurs. These primitive primates, with large, round eyes and wet, dog-like noses, are unique to Madagascar, an island in the Indian Ocean, off the southeast coast of Africa.

Lemur ancestors arrived in Madagascar some 65 million years ago, perhaps floating over from mainland Africa on mats of vegetation. Isolated on the island, the Earth’s fourth largest, lemurs evolved independently from other primates, diverging into a striking cast of characters: From the teddy-bear cute black-and-white ruffed lemur to the creepy, bat-like aye-aye.

Zohdy’s favorite is the mouse lemur, the smallest primate in the world. “The adults weigh about as much as a fun-sized package of M&Ms and can fit into the palm of your hand,” she says. “The babies are no bigger than a Ping-Pong ball and, basically, all eyeballs.”

A new IMAX movie “Island of Lemurs: Madagascar,” opening nationwide on April 4, features the work in Ranomafana of famed primatologist Patricia Wright, one of Zohdy’s mentors. “The imagery in the film is so rich, it tugs on my heartstrings,” Zohdy says. “I hope the film makes more people around the world aware of the dire ecological situation in Madagascar.”

Watch the trailer for the IMAX movie:

Zohdy has been researching lemurs in Madagascar for seven years. Last summer, she broadened her focus and led an Emory infectious disease field team in Ranomafana, made up of students from a range of specialties. The Emory team is gathering baseline data for an ambitious “one health” intervention. The goal is to bolster the health of the rural poor around Ranomafana, who are struggling to stay fed, sheltered and alive, while also conserving the ecosystem of the World Heritage site.

Zohdy’s rubber boots make loud sucking sounds as she trudges through thick mud towards a wooden suspension bridge spanning the Namorona River, roaring and rushing over its rocky bed even during the dry season.

“Check out that spider web,” she says, as she leads the way across the bridge. She points up at gossamer threads hanging above the water, leading out of the forest on one side of the river and stretching 40 feet to connect with the trees on the opposite bank. The recently discovered Darwin’s bark spider, she notes, spins the largest webs in the world, and its silk is the toughest biological material ever studied, more than 10 times tougher than Kevlar.

Crested drongos – large black birds sporting what look like elegant coattails and fancy feather headdresses – chatter in the trees alongside the slick forest trail, which is now leading steeply up a lush hillside.

Zohdy pauses when she hears breaking leaves in the canopy and catches a whiff of a musky, zoo-like smell. “Golden bamboo lemurs. They are right above us,” she says softly. “Don’t open your mouth when you look up,” she quickly adds. “People have been peed on.”

A golden bamboo lemur, photographed in Ranomafana by Sarah Zohdy.

The dusky-gold creatures, which look like a cross between a Koala bear and a raccoon, are critically endangered. They are one of three species of lemurs in the park that subsist almost entirely on the tender leaves and shoots of bamboo.

The greater bamboo lemur is the rarest of them all. Just two remain in the 160-square-mile Ranomafana National Park – a father and his daughter – and only about 60 survive in the wild. Like the giant panda, the greater bamboo lemur has molars capable of slicing and crushing the tough trunk of bamboo.

“It’s a fascinating evolutionary adaption,” Zohdy says, that allows them to survive during the dry season, when the more tender bamboo shoots and leaves are not as readily available. Loss of habitat and shifts in climate, however, have lengthened the dry season. “That means the greater bamboo lemurs have to chew on the tough trunks longer, which wears down their teeth,” Zohdy says. “When their teeth go bad, they starve. It’s not like they can go to a bamboo lemur dentist and get dentures.”

Since humans began settling on the island, only about 2,000 years ago, bringing a rice-growing culture with them, much of the natural habitat and its wildlife has disappeared, including at least 17 species of lemurs.

“When I first came to Madagascar, I thought the whole island would look like a BBC nature special,” Zohdy recalls. Instead she was stunned during the ten-hour drive from the capital of Antananarivo to Ranomafana to see a largely treeless landscape of terraced rice paddies and the occasional smoke from slash-and-burn agriculture.

Watch a video about an Emory "one-health" project in Madagascar:

In the steep landscape of Ranomafana, the homes of villagers and their food crops and livestock bump up against the remaining patches of primordial wilderness. The crowding puts both people and animals at risk. “When you have humans encroaching on wildlife habitat you have huge potential for zoonotic diseases, and the emergence of new diseases,” Zohdy says. Pneumonic plague and virulent strains of flu are examples of deadly outbreaks that have occurred in Madagascar in recent years.

The “one health” approach of the Emory infectious disease team may be key to solving some of the complex problems facing the Malagasy people and the fragile Ranomafana ecosystem. “To really understand human health, animal health, and environmental health, you have to study all three at once,” Zohdy says.

During the summers, going back to 2011, Emory student-researchers have collected fecal samples of lemurs, people and their livestock. These samples, along with mosquitos and ticks the team is collecting, are sent back to Atlanta for analysis of pathogens they may contain.

The project is part of a large-scale effort of conservation and global health being coordinated by Thomas Gillespie, an Emory professor of Environmental Sciences and Environmental Health. The data the students are gathering will help guide a health care improvement effort through a new non-profit agency called PIVOT.

Madagascar is home to half the world's chameleon species. Photo by Sarah Zohdy.

One evening, Zohdy leads students on the team on a night hike up the side of a mountain. The forest is eerily silent. A thick mist snakes along the ground and drifts up through the silhouettes of trees.

The researchers’ headlamps slice like lasers across the understory, occasionally striking treasure. An iridescent green and blue chameleon looks like a jeweled dragon clinging to the branch of a sapling. A golden moth the size of a small bird fans its wings across a clump of eucalyptus leaves.

“Do you hear that high-pitched trill, like a tiny, far-away bell?” Zohdy asks. “That’s a mouse lemur.”

Tiny pairs of glowing eyes pop out of the darkness. Mouse lemurs are nocturnal, and their eyes shine due to the reflective effects of sensitive night vision. The eyes appear, then vanish in a flash, as the shy creatures dart amid the branches of small trees.

Zohdy instructs everyone to switch their headlamps from white light to red, so the lemurs don’t get blinded.

Seen in well-lit photographs, the brown mouse lemurs populating Ranomafana are charming. They have a beguiling gaze and tiny, elegant hands that look more human than animal, complete with delicate fingernails.

Moving through the dark forest, however, these miniature primates become like lemures, Latin for ghosts and the origin of the word lemurs. They flit through the trees alongside the trail, watching the humans with wide, curious eyes that reflect the red glow of the curious humans watching them back.

 Watch a video about the making of the IMAX movie:

In Madagascar: A health crisis of people and their ecosystem

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