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Asia's Elusive Acrobat
by Howard Youth
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Asia TrailThe clouded leopard could be called a little big cat. It's got the head of a big cat on a small cat's body. An adult female weighs just 25 to 35 pounds—about as much as a two- or three-year-old child—and an adult male may weigh about double that. Even the largest clouded leopard (Neofelis nebulosa) is lilliputian when compared with the heavy hitters with which it shares the subfamily Pantherinae, including lions and tigers, which tip the scales at up to 500 and 570 pounds, respectively.

clouded leopard
While little is known about clouded leopards' behavior in the wild, it's likely their numbers are declining, and they have been extirpated from Taiwan. (Jessie Cohen/NZP)

You aren't likely to see a clouded leopard unless you visit one on the Smithsonian National Zoo's Asia Trail, or at another zoo. This cat has the vanishing skills of David Copperfield and the grace and agility of Jackie Chan, yet lacks the celebrity of either. It skulks in one of the world's most crowded corners and no one knows exactly how well it is doing. But most experts believe it has fallen on hard times over large parts of its range, from southern China to the eastern Himalayas and south to Sumatra and Borneo. There, satellite images depict habitat scraps left in areas once blanketed by forest. Even where ample habitat remains, clouded leopards are extremely difficult to find. You are far more likely to spot a wild clouded leopard's gray-, brown-, and black-swirled coat hanging in a market in China, Cambodia, Laos, Myanmar, Nepal, Thailand, or Vietnam, where illegally obtained pelts, in the absence of the real thing, may sell as "tiger skins."

Under the Convention on International Trade in Endangered Species of Wild Fauna and Flora, international trade in clouded leopards is banned. But that hasn't stopped a surging demand in Asia for the animals' fur, teeth, and bones, which are used in traditional medicine. While listed as vulnerable on the 2006 IUCN Red List of Threatened Species, clouded leopards get endangered status on the U.S. Fish & Wildlife Service's endangered species list. Such designations, however, did not save the distinct subspecies of clouded leopard that inhabited Taiwan, where its fur was prized for ceremonial use. The last confirmed sighting of a clouded leopard there was in 1983.

For the past four years, National Zoo reproductive physiologist JoGayle Howard and her colleagues have been taking new steps to improve the clouded leopard's prospects. In 2002, Howard and Nashville Zoo President Rick Schwartz initiated the Thailand Clouded Leopard Consortium, an international effort that supports clouded leopard conservation in the wild in Thailand and works to improve breeding success of clouded leopards in Thai zoos. Participants include the National and Nashville zoos, Khao Kheow Open Zoo in Chonburi, Thailand, the Zoological Park Organization of Thailand, the Asian Wildlife Consultancy, and the Clouded Leopard Species Survival Plan (SSP), which manages North American zoo breeding and research efforts. Khao Kheow Open Zoo is the consortium's headquarters and the site of the clouded leopard breeding program in Thailand. For four years now, the consortium has been forging ahead with its efforts to save a particularly cagey cat.

Mystery Cat
How many clouded leopards remain in the wilds of Asia? One often-quoted estimate is fewer than 10,000. "The truth is, there have been no surveys, no numbers in the wild—we don't know if there are 10,000 out there," says Howard.

So far, only six wild clouded leopards have been radiocollared and tracked, all of them within Thailand. In the late 1990s, Sean C. Austin, a biologist working for the Caesar Kleberg Wildlife Research Institute at Texas A&M University-Kingsville, radiotracked one male and one female clouded leopard for 15 months in Khao Yai National Park, northeast of Bangkok. He found his subjects to be "very active in terms of movement and distances traveled." The female had a home range of 12.8 square miles and the male of 14.2 square miles. "The size of the areas used," he wrote, "is surprising as these areas greatly exceed the size of male leopard (Panthera pardus) home ranges [6.9 square miles] elsewhere in Thailand." Based on the distances traveled and movement patterns, Austin supported earlier assertions that while clouded leopards may rest in trees, they almost certainly do much of their moving around and hunting on the ground. "It would be difficult," he wrote, "to cover these daily distances without spending much time on the ground."

Between 2000 and 2003, biologist Lon Grassman, also with the Caesar Kleberg Wildlife Research Institute, radiocollared and tracked two male and two female clouded leopards in the Phu Khieo Wildlife Sanctuary in northeastern Thailand. Grassman tracked each animal for between seven and 17 months and found that all four had considerable overlap in their home ranges, which spanned between 8.8 and 17.4 square miles. But not all used the same habitats. While closed-canopy forest comprised 84 percent of the home ranges, one male used an open-canopied forest and grassland habitat more than expected. Grassman found that his cats' activity did not follow a fixed pattern but that most activity occurred at dawn or dusk or at night. Austin's and Grassman's data helped change perceptions of an animal once assumed to be a strictly nocturnal, arboreal forest hunter.

Aside from these six radiocollared cats and photos taken by motion-detecting infrared cameras, there is little more than speculation about the clouded leopard's remaining distribution, natural history, and conservation needs. Much of what we do know comes from anecdotal information or from observations made at zoos, including our knowledge of the clouded leopard's almost mythical agility. "I call them the acrobats of the forest," says Howard. "They can jump ten to 12 feet from tree to tree, balance on little branches, and traverse a horizontal tree trunk upside down." They can also hang upside down from a branch using just their hind legs, and clamber head-first down a vertical tree trunk, thanks to their very flexible ankle joints.

To aid them in their arboreal activities, clouded leopards have large, sharp-clawed paws, short legs, and long tails that provide balance. Their bodies may be up to three feet long, but their sweeping tails tack on at least another 30 inches. In the dwindling number of areas where tigers or leopards share their habitat, clouded leopards no doubt employ their camouflaging coats and tree-climbing abilities to hunt and to avoid becoming dinner themselves.

It's not clear how arboreal clouded leopards are. (Jessie Cohen/NZP)

Clouded leopards' fearsome dentition hints at their killing power. They have the longest canines, relative to body size, of any feline, which they use to kill a variety of terrestrial and arboreal creatures. Grassman collected and analyzed wild clouded leopard feces, or scat, in Thailand during his study, and also compiled observations of clouded leopards' hunting activity. According to his data, the following species are clouded leopard prey: red muntjac (Muntiacus muntjak), Java mouse-deer (Tragulus javanicus), hog deer (Axis porcinus), Asiatic brush-tailed porcupine (Atherurus macrourus), Indochinese ground squirrel (Menetes berdmorei), Malayan pangolin (Manis javanica), slow loris (Nycticebus coucang), Phayre's leaf-monkey (Trachypithecus phayrei), and mice. In other places, clouded leopards are known to eat wild birds, poultry, wild boar, and even orangutans (Pongo spp.).

Stalking Cats and Their Hunters
In 2003, with hopes of learning more about clouded leopard distribution while bolstering park protection efforts in Thailand, Howard and Peter Leimgruber, an ecologist at the National Zoo, started the Thailand Carnivore Conservation Project. This collaboration between the Zoo, the international wildlife trade watchdog WildAid, the Cincinnati Zoo, and the Thailand Department of National Parks, Wildlife, and Plant Conservation includes monitoring, ranger training, and a field survey of carnivores that will culminate in a GIS map of their distribution.

The project began at Khao Yai National Park in 2003, when 20 rangers attended an ecology workshop. Six of the attendees were selected to form the Carnivore Monitoring Team. As part of their training, these rangers learned to identify tracks of different carnivores from plaster casts made from paw prints, and to identify and record any other signs—scrapings, rubbings, scat—that they come across in the forest.

Data collection began in 2004. The rangers set up, checked, and rotated 20 motion-detecting infrared cameras bought with funds raised by Friends of the National Zoo's Young Professionals program and donations from other North American zoos. The cameras were strapped to trees and moved after a month to other parts of the park, their film taken out for developing and replaced with fresh rolls. While checking the cameras, rangers also looked for other signs that carnivores were present, including tracks and claw marks on trees.

The first year, the cameras photographed Asian black bears (Ursus thibetanus) and sun bears (Helarctos malayanus), but no clouded leopards. The next year yielded five photos of clouded leopards. At the base of one tree, a camera snapped shots of wild cats from three other species: leopard cat (Prionailurus bengalensis), Asian golden cat (Catopuma temminckii), and marbled cat (Pardofelis marmorata).

The cameras caught more than just wildlife. They also documented many intrusions by humans into the cats' habitat. "On almost every roll of film there are people," says Howard. "The park closes at night but there is a lot of illegal activity. Most people in the photos are carrying a gun or have a dog with them. It's pretty safe to say that these people are poachers." In addition to animals, aloe wood is also being removed from the park for use in lotions and perfumes. "Poaching is all over the park," says Howard. At about 535,700 acres—a bit larger than Great Smoky Mountains National Park in North Carolina and Tennessee—Khao Yai is one of Thailand's most expansive conservation areas, but it has only a small staff to patrol its borders and interior. "It's hard to track poaching there, it's a huge area. But there are several hotspots and we're now plotting the frequency of occurrences," says Howard.

This effort is intended to be ongoing, and Khao Yai, just one link in a network of five connected parks, was just the beginning. "Our team is ready and has been invited to expand into the next park," says Howard, who is now trying to raise funds for field cameras and training at nearby Thap Lan National Park.

Matchmaking: A Dicey Proposition
If all goes well, a female clouded leopard gives birth to two to five cubs following a gestation period of between 86 and 93 days. This cycle has played out many times at the Zoo's Conservation and Research Center (CRC) in Front Royal, Virginia, where breeding efforts and reproduction studies for the species have been underway since 1978.

A total of 72 clouded leopards have been born at CRC; many were sent to other North American zoos as part of the ongoing SSP, which aims to create a self-sustaining zoo population. Yet this remains a distant dream, primarily because unbonded males often attack and kill females upon introduction. "Male aggression is the number-one problem," says Howard. "We're still trying to figure out why males behave like this." As a result, it's been very difficult to mix and match animals to create a varied zoo gene pool.

Across North America, 99 clouded leopards residing at 34 zoos have been part of the SSP. But due to the difficulty in successfully pairing animals, most of the current zoo population is descended from only seven founders. To date, no SSP males have bred with more than one female. (Outside of North America, there are 128 clouded leopards in 38 zoos.)

Enter Thailand, a country with conservation infrastructure and the largest zoo clouded leopard population in Asia. Unlike North American populations, the Thai zoos' clouded leopard populations exhibit rich genetic diversity. In 2002, the Zoological Park Organization of Thailand (ZPO) maintained a total of 27 clouded leopards in their five zoos, 24 of which were born in the wild and then either given to zoos or confiscated from poachers by wildlife authorities. Because of their wild lineage, these animals were an excellent foundation for beginning a breeding program.

Howard and the Nashville Zoo's Rick Schwartz made a proposal to the ZPO to develop a collaborative international program to improve its clouded leopard husbandry and nutrition and to begin a breeding program. Once the consortium was set up in 2002, all five ZPO zoos sent a total of 23 clouded leopards to the new breeding program at the Khao Kheow Open Zoo.

Cub Jogayle was born as a result of zoo breeding efforts. (Juan Rodriguez)

After the animals arrived at Khao Kheow, the key was to find ways to make pairs that would breed and not fight. Ken Lang, a National Zoo carnivore specialist who has worked at CRC for 28 years, was the Thai consortium's first onsite manager. Lang has mastered the ability to match clouded leopards—a process Howard calls "more an art than a science." With modesty, Lang says, "I've experimented over the years with various combinations of possibilities. It had a lot to do with the different personalities of the cats, but age makes a big difference."

Lang and other SSP clouded leopard experts find that males younger than a year are usually very easy to match with females, and that males younger than two still have a fairly good chance of matching successfully, depending upon the cats' temperaments. Clouded leopard males older than two that have reached puberty are far more likely to attack introduced females. Now that the consortium's breeding activities are up and running, some pairs that bonded early on in Thailand will be sent to the United States to augment genetic diversity in the SSP.

Meanwhile, the first Khao Kheow cubs to reach the United States may soon meet each other. Right now, Lang is finishing up a four-month attempt to match a Khao Kheow female named Jogayle with a male born at the Point Defiance Zoo and Aquarium in Tacoma, Washington, named Rama. The pairing has been rocky, so Jogayle will be sent to the Nashville Zoo to meet an unrelated Khao Kheow male named Dao, which has a gentle disposition. Lang says that hand-reared animals, such as those from Khao Kheow and CRC, are far easier to work with because they are generally not as skittish as wild cats and thus easier to observe. "A lot depends on how much the animals trust you," says Lang, "and how much they'll do in front of you. Other cats will just sit in the nest-box and hide."

A Flare for Things Scatological
Elsewhere at the Zoo, other clouded leopard research is being done that requires no cat observations at all. Zoo scientists have pioneered noninvasive hormone monitoring that enables scientists to learn about wildlife without disturbing, or even seeing, their subjects. Zoo reproductive health specialist Katey Pelican oversees lab work that has revealed a lot about clouded leopards from scat samples collected daily at the Khao Kheow Open Zoo. Since 2002, Pelican, Kate MacKinnon, a Washington State University graduate student who works as a technician, Howard, and their colleagues have analyzed more than 20,000 fecal samples.

What can you learn from scat? First, by measuring reproductive and stress hormone levels in samples from 23 clouded leopards, Pelican's team confirmed why, at the beginning, Khao Kheow's cats were neither thriving nor reproducing. Nutritional analysis confirmed that the cats were eating an unbalanced diet that, among other things, was very low in calcium. Stress hormone levels indicated that the small, low enclosures in which the cats lived, many close to tigers, bears, and other large carnivores, left the cats nervous and insecure.

"They had no access to height, which is very important," says Pelican. At the new Asia Trail at the National Zoo, for example, visitors see two clouded leopards in an exhibit that is about 15 feet tall. To address the need for height and shelter at Khao Kheow, Ken Lang used tall vacant hornbill aviaries from the zoo that were outfitted with climbing structures and nest boxes where the cats could hide and raise their young. The enclosures already included lush vegetation that provided extra cover, and sat well away from tigers, bears, and other carnivores. The clouded leopards' diet was changed from chicken parts to live quail and fresh, whole chicken, with vitamin and mineral supplements added.

How did a change of diet and space affect the cats? At the beginning of the program in 2002, only half of the females exhibited estrous cycles, and tested males had low sperm counts. About six months into the project, however, most of the females that had not been cycling started to. Males also had high sperm quality. "The data are clear," says Pelican. "Those management changes were important for a successful breeding program for clouded leopards in particular and carnivores in general because carnivore managers around the world often do not provide a proper, balanced diet with sufficient calcium, or enclosures that make the animals comfortable."

Park rangers identify clouded leopard tracks. (Kate Jenks)

But that's not all scat has to tell us about clouded leopards and other wildlife. Fecal samples from 19 Thai carnivore species kept at Khao Kheow, including civets, bears, jackals, and various cats, were sent to the National Zoo. There, geneticist Lori Eggert, through genetic sequencing, created DNA markers that make it easy to differentiate between species. This work confirmed that genetic tests can be used to identify species in the wild by their scat samples. It's an important advance that allows rangers and researchers to survey the distribution and density of wildlife populations without seeing or capturing clouded leopards.

The research team also put fecal samples to the test under varied conditions to determine how long it takes for scat to lose its DNA and hormones. Tested in shade, sun, and in wet and dry seasons, Khao Kheow samples gave the scientists information on the rate of DNA and hormone degradation under field conditions and how valuable new or old scat will be when collected in the field.

A Clearer Future for Cloudeds

As with this scat analysis, Zoo researchers and their colleagues, whenever possible, tie together field and zoo efforts, and Thai and North American interests. They have facilitated meetings between rangers and zoos so that those in the field can see, up close and personal, the cats they are working to save. They also bring keepers to meet the field team. These days, Khao Kheow keepers take more interest in the animals for which they care. "Now they want to do the behavioral observations. They want to see the babies being born," says Lang. In May and June 2006, the keepers used nest-box cameras to monitor and video-record births in the latest two litters.

After returning from Thailand and compiling their data, Howard and other Zoo researchers share results with their Thai colleagues. "We teach them so that they'll be able to take over," says Lang. "They see we're not just going in there and taking. The partnership benefits them."

Within the consortium, North American zoos, including the Nashville Zoo, Point Defiance Zoo, Brookfield Zoo in Brookfield, Illinois, the Bergen County Zoological Park in Paramus, New Jersey, and the National Zoo, have contributed employees and their time for stints in Thailand. "It's always been a multi-zoo effort. Now we've got more interest because people see the success we're having and the long-term nature of it," says Lang. Former National Zoo keeper Rick Passaro now manages the program full time at Khao Kheow, working with the Thai staff and the revolving cadre of North American zoo personnel.

"Our greatest success," says Lang, "has been the number of babies." So far, 13 cubs have been born and survived to contribute to the breeding program, including the two that were exported to CRC and the Nashville Zoo. Now four years old, the Thai breeding program will continue for at least three more years after the recent signing of a memorandum of understanding between Thai and North American zoos. Although there are no formal plans now, some day future zoo cubs also may be reintroduced into wild areas where clouded leopard populations have been eradicated or reduced to dangerously low levels.

"Thailand is home to nine wild felid species, very few of which have been well studied or surveyed. These clouded leopard programs provide an example and hope for work with other declining cat species. Howard and the Cincinnati Zoo's Bill Swanson, for example, recently spearheaded a similar breeding program and field survey for fishing cats (Prionailurus viverrinus). Meanwhile, clouded leopards remain a worry for conservationists in a country with dwindling forest cover, shorn down from about 50 percent in the 1960s to about 20 percent by 2000. "The good news is that we're working on saving clouded leopards at the right time, the right place," says Howard. "It's not too late for them."

—Contributing editor Howard Youth's recent ZooGoer articles have focused on Florida panthers, desert tortoises, and black-footed ferrets.

ZooGoer 35(6) 2006. Copyright 2006 Friends of the National Zoo. All rights reserved.

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