jueves, 14 de agosto de 2008

New Rare Lemur Group Found in Swamp

lemur photo

July 22, 2008—A new population of wrinkly-faced, bamboo-eating lemurs has been found in a swampy region of east-central Madagascar—more than 240 miles (400 kilometers) from the other only known group of the primates, listed as critically endangered by the World Conservation Union, conservationists announced today.

The 2007 finding comes after years of rumors that the so-called greater bamboo lemur had been sighted in the Torotorofotsy wetlands. Now that it's confirmed, the newfound group has renewed experts' hopes that the species will survive.

"Finding the extremely rare Prolemur simus in a place where nobody expected it was probably more exciting than discovering a new lemur species," conservation geneticist Edward Louis of Henry Doorly Zoo said in a statement.

Louis coordinated the joint research mission between the zoo and MITSINJO, a Malagasy nonprofit. The work was supported by the Margot Marsh Biodiversity Foundation and Conservation International.

(Read about three new species of palm-size lemurs found in Madagascar in 2006.)

Scientists suspect that 30 to 40 of the lemurs—known for cracking open giant bamboo with their powerful jaws—live in the wetland, where bamboo is still their main staple.

The new group joins another population of about a hundred animals in the island's northern bamboo forests, which are under threat from illegal logging and habitat destruction, according to Conservation International.

—Christine Dell'Amore

Photograph courtesy Jonathan Linus Fiely/Conservation International

"Cross Dressing" Lemurs Appear Male to Avoid Conflict

Matt Kaplan
for National Geographic News
July 24, 2008
Young female red-fronted lemurs in Madagascar adopt male coloration to dupe their aggressive female groupmates, a new study found.

These "cross dressing" primates thus avoid the wrath of older females, which would attack them to reduce sexual competition.

All red-fronted lemurs are born with the same greyish brown fur and rusty-red crowns that distinguish adult males. 

At 7 to 17 weeks later, females' coats change to a cinnamon hue, and their crowns become white.

"We knew from our longer-term observations that there was a lot of female aggression in red-fronted lemurs," said study author Claudia Fichtel of the University of Göttingen's German Primate Center.

"Females compete fiercely over limited breeding opportunities, and we wanted to know if hiding femininity was a way to avoid being attacked," Fitchtel said.

(See a photo of an endangered ring-tailed lemur.)

Not a Target

German researchers monitored a wild lemur population in the Kirindy forest in western Madagascar for five months and recorded behavioral changes as their coats changed color. 

But the scientists also faced a problem: Since all infants appear male, the theory that young sport different colorations to thwart conflicts is tricky to investigate. 

This led Fichtel and her colleagues to look very closely at older females and monitor their attacks. 

They found that males and all young females disguised as males were not targeted by the hostile older females.

Fichtel and her colleagues argue that appearing male has evolved as a defense to keep females from attacking until the masquerading females are strong enough to handle it. That tends to be between 7 and 17 weeks of age.

(Related: "Rainfall Helps Baby Lemurs Survive, Tooth Study Shows" [November 14, 2005].)

Red-fronted lemurs are not the only primates whose youngsters are colored differently than adults. 

In other species this disparity has often been explained as an adaptation that makes infants more noticeable to groupmates. Adults are then more likely to care for and protect infants, Fichtel added.

The study appears in the July issue of the Journal of Physical Anthropology.

Female Dominance

"This provides a fresh perspective into why some primate offspring have a dramatically different coat color," said Sylvia Atsalis, a primatologist at Lincoln Park Zoo in Chicago.

"It tickles scientific minds to think—through a new perspective—about a condition that occurs in many species," she added.

More in-depth analyses should be made into female lemurs and their behaviors, other scientists said.

"There has been a long-running argument about how aggressive red-fronted lemurs are to each other," said Alison Jolly, a primatologist at the University of Winchester in the United Kingdom.

"Most of their social life is cuddling and grooming, [but] once in a long while females viciously throw other females out of the group, or more rarely, they have been seen to kill and actually eat another animals' infants," she said. 

"The question is, Is infanticide or targeting so rare that it couldn't have much influence over evolutionary time?"

(Read: "Ecotourism Driving Tibetan Monkeys to Infanticide" [July 20, 2007].)

Patricia Wright, a primatologist at Stony Brook University in New York, added that genetic tests should be done to see how lemurs perceive color.

"We've only recently learned that not all lemurs see color," Wright said.

"Sometimes only females have color vision, a trait that makes males dependent upon them for finding berries and secures female dominance."

Newfound Monkey Species "Rarest in Africa," Expert Says

Steven Stanek
for National Geographic News
August 4, 2008
A recently discovered African monkey could soon be extinct, scientists report.

The first comprehensive study of a three-foot-tall (one-meter-tall) monkey discovered in Tanzania found that just 1,117 individuals exist, according to researchers with the Wildlife Conservation Society (WCS). 

The Rungwecebus kipunji on Monday was listed as "critically endangered"—the highest possible threat level before extinction—by the International Union for Conservation of Nature (IUCN) in response to the WCS research. 

"Without a doubt, they are the rarest monkey in Africa, and I would imagine there are very few with such small numbers in the world," said Tim Davenport, Tanzania country director for the WCS, who led one of the two research teams that separately identified the primate in 2005.

Davenport helped IUCN to assess the conservation status of the kipunji. 

Mike Hoffmann, a Washington-based program manager for IUCN, said his organization relies on information from researchers in the field about animal populations to determine a species' conservation status. 

"They've got very good information," Hoffman said of Davenport's teams. "This is information from people working on the ground conducting detailed surveys."

New Genus

Davenport said the main threats to the kipunji are poachers and illegal logging in its habitat in Tanzania's southern highlands and the Udzungwa Mountains, which rise 8,000 feet (about 2,400 meters) above sea level.

As adults, the brownish gray, long-haired monkeys weigh up to 40 pounds (18 grams) and emit a unique "honk-bark," so named because it sounds like "a goose followed by a dog," Davenport said.

Originally scientists thought the monkey was a new species of mangabey, but in 2006 DNA analysis revealed it to be an entirely new genus of primate named Rungwecebus—the first genus discovered in Africa since 1923.

Patricia Wright, a primatologist at New York's Stony Brook University, said: "If it is indeed its own genus, then it becomes even more important that we save it." 

The primate could disappear in 20 to 50 years without safeguards to preserve it, said Wright, a member of National Geographic's Conservation Trust Advisory Board.

(The Conservation Trust is part of the National Geographic Society, which also owns National Geographic News.)

Counting Each Individual

The WCS study—published in the July issue of the journal Oryx—was the result of more than 2,800 hours of fieldwork by scientists. 

Davenport said most primate censuses estimate populations through sampling and statistical extrapolation. 

"What we decided to do was a little bit more time consuming ... actually try and count every individual," he said. "It was a bit of an unusual study." 

It took 20 researchers six months to map the movements of 34 separate groups of kipunji, using GPS mapping systems. Each group has 30 to 36 individuals.

The team found the monkeys—which sport distinctive, upright crests of hair on their heads—live in a range of just 6.8 square miles (17.7 square kilometers) in two remote regions, which explains why they eluded Western scientists for so long. 

The researchers said the kipunji's tiny population and "shyness" also contributed to the primate's obscurity.

Primates Newly Listed as Critically Endangered

PHOTOS: New Primates in IUCN Critically Endangered List

August 12, 2008—Numbers of the black-and-white ruffed lemur (Varecia variegata)—which, like all lemur species, is found only on the African island of Madagascar—have dwindled as a result of predation and habitat loss.

Last week the International Union for Conservation of Nature (IUCN) added several species and subspecies of primates, including the ruffed lemur, to the "critically endangered" category in its Red List of Threatened Species.

The additions were made as part of a study by hundreds of experts that suggests half of the world's apes, monkeys, and other primates are in danger of extinction.

PHOTOS: New Primates in IUCN Critically Endangered List

Gray-Shanked Douc 

Scientists first discovered the gray-shanked douc (Pygathrix cinerea) in 1997. Native toVietnam, fewer than a thousand of the primates are believed to exist. 

Two years ago an IUCN survey estimated that 65 percent of Vietnam's primate species were considered "endangered" or "critically endangered."

In August 2008 the conservation organization released a new report that estimates 70 percent of Asian primate species are considered "threatened," "endangered," or "critically endangered." The gray-shanked douc is among the primates that are now listed as critically endangered

PHOTOS: New Primates in IUCN Critically Endangered List

Cotton-Top Tamarin 

The cotton-top tamarin (Saguinus oedipus)seen above was photographed at Rolling Hills Wildlife Adventure in Salina, Kansas.

About 1,800 members of the squirrel-sized monkey species native to Colombia live in captivity. Fewer than a thousand of the primates, newly listed as "critically endangered" by the IUCN, are found in the wild.

PHOTOS: New Primates in IUCN Critically Endangered List

Celebes Black Macaque 

A Celebes black macaque (Macaca nigra)strips ripe fruit from a fig tree in Tangkoko-Dua Saudara Nature Reserve on Sulawesi, one of two Indonesian islands that serve as the primate's sole habitat.

The monkey species is often mistaken for a type of ape, owing to its black coloring and a truncated tail.

Slightly more than a hundred thousand of the primates are thought to exist. In August 2008 the IUCN added the species to its list of critically endangered animals.

PHOTOS: New Primates in IUCN Critically Endangered List
Pennant's Red Colobus Monkey 

A male adult Pennant's red colobus monkey(Procolobus pennantii) is photographed in the wild on Bioko Island, 20 miles (32 kilometers) off the coast of Cameroon in central West Africa. (See more photos of animals on the island.)

Of the continent's 13 red colobus monkey species, 11 are listed as critically endangered by the IUCN. The nonprofit added the Pennant's red colobus monkey to its list of critically endangered animals in 2008. 

PHOTOS: New Primates in IUCN Critically Endangered List

Highland Mangabey 

Three years ago scientists discovered a new monkey species known as the highland mangabey (Lophocebus kipunji), or kipunji, seen above, in a mountainous region ofTanzania in East Africa. 

Experts estimate that fewer than a thousand of the medium-size, long-tailed tree-dwellers live in the wild, a figure that led the IUCN to list the primate as "critically endangered" in 2008. (See"Newfound Monkey Species 'Rarest in Africa,' Expert Says" [August 4, 2008].) 

Among the hundreds of primate species and subspecies known to science, 53 have been discovered since 2000. 

Where have all the monkeys gone?

Nearly half of the monkeys, apes and lemurs in the world are in imminent danger of disappearing from the planet, according to a new survey. The news comes even as a separate new census has uncovered far more gorillas than expected.

The International Union for Conservation conducted its first survey of the 634 known primates in five years and found that 48 percent face extinction. Particularly at risk are the great apes like 

"The situation is far more severe than we imagined," said Russell Mittermeier, president of Conservation International and chairman of the IUCN's primate group, at the release of the analysis in Edinburgh. Although
tropical forest destruction remains the main cause, "in many places, primates are quite literally being eaten to extinction."

Asian primates are at particular risk, with nearly all of the monkeys of Vietnam and Cambodia dying out, including gibbons, langurs and leaf monkeys. And in Africa, relatively obscure species of red colobus monkeys may already be extinct: Bouvier's red colobus and 
Miss Waldron's red colobus have not been seen in at least 25 years.

But the news out of Africa isn't all bad. A survey by the Wildlife Conservation Society and the government of the Republic of Congo turned up more than 125,000 
western lowland gorillas—a formerly critically endangered species. That more than doubles the entire known population of the human relative.

The key to their survival -- and the reason so many gorillas had been hidden for so long --was the remoteness and inaccessibility of the 
jungle fastnesses and swamps where they make their home. "We knew from our own observations that there were a lot of gorillas out there, but we had no idea there were so many," said Emma Stokes, who led the survey efforts, at the announcement in Edinburgh.

Unfortunately, the hopes for a similar find of African red colobuses or Asian gibbons are not as good, according to the IUCN.

Extinction Threatens Half of Primate Types, Study Says

Brian Handwerk
for National Geographic News
August 5, 2008
About half the world's apes, monkeys, and other types of primates are in danger of extinction, according to a new study that predicts a bleak future for many of humankind's closest relatives.

Primates are falling prey to intense hunting and rapidly losing their habitats to deforestation, the study released Monday said.

"[This is] a very important and absolutely horrifying report," said primatologist Frans de Waal, director of the Living Links Center at Emory University. 

"There have been isolated pieces of data around for years, which have sketched an ever darker picture," de Waal said, adding that the report supports the bleaker prognoses. 

Hundreds of international experts helped to classify 634 primates for the Red List of Threatened Species using criteria established by the International Union for the Conservation of Nature (IUCN). They found nearly half the species and supspecies are endangered. 

Scientists have discovered 53 new primate species since 2000, including 40 on Madagascar alone, and no one knows what others may exist. Some could vanish before they are even known to science.

(Related story: "Newfound Monkey 'Rarest in Africa,' Expert Says" [August 4, 2008])

The report, released at the 22nd International Primatological Society Congress in Edinburgh, Scotland, was funded by Conservation International (CI), IUCN, the Margot Marsh Biodiversity Foundation, and Disney's Animal Kingdom. 

"Scary" Situation in Asia

The news was particularly bad for Asian primates—more than 70 percent of which are listed as "vulnerable," "endangered," or "critically endangered."

"I think what's most alarming is just how bad the situation is in the Asian region, particularly in Southeast Asia," said Mike Hoffmann, an IUCN scientist based in Washington, D.C. 

"In countries like Vietnam and Cambodia pretty much 90 percent of the primate fauna [including gibbons, monkeys, and langurs] is at risk of extinction. That is pretty scary." 

Many primates are caught between the two distinct threats: hunting and habitat loss. 

In a statement from Edinburgh, CI's Russel A. Mittermeier said, "Tropical forest destruction has always been the main cause, but now it appears that hunting is just as serious a threat in some areas, even where the habitat is still quite intact." 

"In many places, primates are quite literally being eaten to extinction," added Mittermeier, president of CI and longtime chair of the IUCN Species Survival Commission's Primate Specialist Group. 

Hunting feeds an insatiable appetite for bush meat, but it also satisfies demand for the primate pet trade and the many body parts used in traditional Chinese medicine—particularly in Southeast Asia. 

IUCN's Hoffmann added, "When you go into even some of the protected areas there, you just don't see anything. The forest is pretty much empty." 

Glimmer of Hope?

De Waal said the primates' plight appears grim. 

"It is reason to be extremely pessimistic," he said. "This situation can be changed only with the explicit support of governments in the primates' native countries as well as the international community."

But IUCN's Hoffmann stressed that such support could turn the tide. 

"We already know that if we invest in targeted conservation action we can see results," he said. 

Conservation efforts in Brazil, for example, led the black lion tamarin, and golden lion tamarin to be downlisted to "endangered" from "critically endangered" in 2003. 

"The problem is that [conservation efforts] require continuous investment," Hoffmann said. 

"Once you initiate a conservation action plan, you're probably going to see some rewards, and species recovering, but then you cannot assume the species is safe." 

Hoffmann encouraged people in primate-poor locales like the Unites States and Europe to get out and visit nations that have primates. 

"See what people are doing on the ground to save these species," he said. "Local conservation NGOs are out there doing fantastic work. Ask how you can get involved in some way." 

Sue Margulis, of the University of Chicago and the Lincoln Park Zoo, said conservation can also start much closer to home. 

"It's painfully easy to ignore the role that each of us can play in primate conservation, because the ex situ work is so far removed from our daily lives," she said. 

"However, it's critical that we recognize that even small things that we do can make a conservation impact, and do whatever we can in this regard, whether it is recycling cell phones or purchasing products made with sustainable palm oil [which combats deforestation], we need to act." 

Emory's De Waal said that all primates have intrinsic value as species and play important roles in their environments. 

"Primates also help us understand ourselves and our evolution, since we are primates," he said. 

"It's a pathetic situation that half our relatives may disappear."

Gorilla "Paradise" Found; May Double World Numbers

Dan Morrison
for National Geographic News
August 5, 2008
Deep in the hinterlands of the Republic of the Congo lies a secret ape paradise that is home to 125,000 western lowland gorillas, researchers announced today.

The findings, if confirmed, would more than double the world's estimated population of gorillas.

Western lowland gorillas are a subspecies classified as critically endangered by the International Union for Conservation of Nature (IUCN).

Their numbers have been devastated in recent years by illegal hunting for bush meat and the spread of the Ebola virus. Just last year scientists projected the animals' population could fall as low as 50,000 by 2011.

Now those predictions may have to be dramatically reworked to incorporate findings released today by the Wildlife Conservation Society (WCS).

A first ever ape census in northern Congo found 73,000 of the gorillas in that country's Ntokou-Pikounda region and 52,000 more in the Ndoki-Likouala area. 

The Ndoki population includes an obscure group of nearly 6,000 gorillas living in close quarters in isolated swamps near Lac Télé.

"We knew there were apes there, we just had no idea how many," said WCS's Emma Stokes, one of the lead researchers in the two-year project.

The gorillas have thrived thanks to their remoteness from human settlements, food-rich habitats, and two decades of conservation efforts in one of the world's poorest countries, Stokes said. 

Shy, But Plentiful

Lowland gorillas are more common than their mountain cousins. The animals are found in tropical forests and swamps in Angola, Cameroon, the Central African Republic, Congo, the Democratic Republic of the Congo, Equatorial Guinea, and Gabon.

Wary of humans, gorillas are notoriously hard to tally in the wild.

To assess their populations, WCS researchers instead used data on the numbers and ages of so-called sleep nests, temporary bedding made of leaves and branches.

Each group of lowland gorillas has a range of about 7.7 square miles (20 square kilometers), and the animals build the nests to sleep in each night before moving on in the morning.

The census work involved crossing hundreds of miles to count nests, then loading data into a mathematical model that estimated the number of gorillas living within a defined area.

In the 17,400-square-mile (28,000-square-kilometer) Ndoki-Likouala region, for example, the nest census found an estimated population density of 1.65 gorillas per square kilometer (equal to about 0.3 square mile).

This means that about 46,200 western lowland gorillas likely live in the area, which runs west of the Sangha River to the border of the Central African Republic.

An additional 6,000 gorillas reside in the region's 646-square-mile (1,040-square-kilometer) Batanga swamps. These wetlands, which are inaccessible to humans for more than half the year, house an estimated five to six apes per square kilometer.

"That's the highest density I've seen," Stokes said, adding that the data suggest Ndoki-Likouala is the subspecies' "largest remaining stronghold."

The discovery "shows that conservation in the Republic of Congo is working," said WCS president Steven Sanderson. 

Almost half the surveyed area lies within officially protected zones or inside timber concessions where logging companies have banned transport of protected animals and weapons on their roads.

Researchers hope the latest census will encourage the government of Congo to establish a new national park in the Ntokou-Pikounda region. 

The census was presented today at the International Primatological Society conference in Edinburgh, Scotland, and some of the data will appear in an upcoming issue of the conservation journal Oryx. 

Perils of Counting Apes

Several experts greeted the survey findings with a mix of excitement and caution. 

"If these new gorilla census figures are confirmed by further surveys, it would be the most exciting ape conservation news in years," said Craig Stanford of the Jane Goodall Research Center at the University of Southern California.

"Nest census data are notorious for varying from one method to the next, however, and I think we should be cautious before assuming the world's known gorilla population has just doubled."

Nesting data were among the factors used in a 2007 IUCN population assessment that placed the western lowland gorilla on the organization's Red List of Threatened Species. 

IUCN estimated the gorillas had declined by more than 60 percent over the past 25 years, and its scientists projected the apes' population could fall to 50,000 as the deadly Ebola virus penetrated deeper into their habitat. 

That report came with a caveat about the reliability of nest counts: "Technical problems with the conversion of ape nest density to estimates of gorilla density preclude a rigorous estimate of range-wide gorilla abundance."

Peter Walsh of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, led the 2007 IUCN assessment. He repeated those concerns when he learned of WCS's findings in northern Congo. 

"It is not that I think that the numbers are necessarily too high," Walsh said. "It is just that I do not trust the assumptions made by the estimation models that are being used."

Nature's Secrets

John Oates, professor emeritus of anthropology at Hunter College in New York, noted that "what does seem clear is that there are still plenty of western gorillas in northern Congo."

He remains cautious, however, about whether the new research should signal a change in status for the great apes.

In addition to habitat loss and hunting, in recent years Ebola has ravaged gorilla habitats bordering the Ntokou-Pikounda survey area, killing 60 percent of the apes in nearby Odzala National Park.

While WCS's Stokes said her survey found "no evidence of Ebola in Ntokou-Pikounda, our general philosophy is Ebola can hit anywhere, anytime."

And with a 90 percent mortality rate among infected gorillas, Stokes thinks the animals deserve all the protection they can get. 

In general, the WCS findings demonstrate that our intensely observed planet still has its biological secrets, added Richard Bergl, curator of research at the North Carolina Zoo.

"It is extraordinary that in this day and age," he said, "there could be a population of a hundred thousand or more gorillas that were essentially unknown to science."

125.000 gorilas encontrados

Os dejo un enlace donde podreis ver un vídeo sobre la noticia en la web de National Geographic,