Spotlight on Zoo Science
April 25, 2007
Clouded Leopard Times Two
New studies reveal a split between clouded leopards deep enough to justify dividing these cats into two species.
Two groups of scientists recently reported, in separate papers published in the December 5, 2006, issue of Current Biology, that there are two species of clouded leopards, not one, essentially doubling the need for conservation measures to save these cats.
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| A clouded leopard from main-land Asia, Neofelis nebulosa, at the National Zoo. |
Biologists traditionally divided the clouded leopards of southern and southeast Asia into four regional subspecies. By that classification, the most widely distributed subspecies is Neofelis nebulosa nebulosa of southeast Asia and China (pictured right). This is the type on the Zoo's Asia Trail.
N. n. macrosceloides occupies northeast India, Nepal, Sikkim, and Bhutan.
N. n. diardi (pictured upper left) lives on the islands of Borneo and Sumatra, and
N. n. brachyura on the island of Taiwan.
The new studies, however, refute this traditional single-species view.
In the Genes
In one of the studies, a team led by scientists from the National Cancer Institute and including National Zoo scientist JoGayle Howard and emeritus veterinarian Mitchell Bush, provided genetic evidence of the split. They examined a variety of molecular genetic “markers,” including mitochondrial DNA, nuclear DNA, and haplotypes (sets of closely linked genes that are inherited as units) in samples from 109 clouded leopards of known geographic origin.
Each of the markers basically said the same thing: Clouded leopards of the Borneo and Sumatra subspecies diardi are distinctly different from all the others, while there are few differences among the mainland cats and those from Taiwan.
The scientists estimate that the two form diverged about 1.41 million year ago. Lions, tigers, leopards, snow leopards, and jaguars diverged into distinct species within a similar time frame of one to three million years ago, and the extent of genetic differences among these species is similar to that between the two types of clouded leopard.
On the Fur
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| A clouded leopard from Borneo, a member of the newly described species, Neofelis diardi. Note the relatively small clouds on its fur compared to mainland clouded leopard below. Image ©WWF-Canon/Alain COMPOST. |
In the second study, scientists looked at geographic variation in the pattern and color of fur in 57 museum clouded leopard skins, including three at the Smithsonian’s National Museum of Natural History. The size of the clouds clearly differentiated Bornean and Sumatran clouded leopards from all the rest—their clouds are small—and, mirroring the genetic results, all the rest have similar large clouds.
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| Mainland clouded leopard. Note the large clouds and light fur compared to the Borneo clouded leopard above. |
In addition, the mainland (plus Taiwan) cats have light, tawny fur while the Bornean and Sumatran cats’ fur is darker and gray to grayish yellow, and there are differences between them in striping and in the number of spots within the clouds.
Interestingly, the authors note that an artist’s depiction of clouded leopards from Sumatra living in a London menagerie about 1825 showed cats that looked quite different from the specimen from China in the same menagerie on which the first scientific description of the species was based in 1821. At that time, the species was named Felis nebulosa, later revised to Neofelis nebulosa. The new Sumatra/Borneo species is named Neofelis diardi.
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| This map shows the distributions of the two species of clouded leopards. Neofelis nebulosa may be extinct in Taiwan. |
Saving Two Species
As a single species, clouded leopards are listed as vulnerable to extinction on the World Conservation Union’s Red List, with their numbers declining due to continued destruction of their forest habitat and illegal harvesting for fur and for other body parts use in traditional medicine.
The results of these studies both simplify and complicate clouded leopard conservation. Clouded leopards are probably extinct on Taiwan, although some hold out hope that a few of these secretive cats survive in remote patches of habitat.
Knowing that the cats there are not distinct from the mainland ones means that mainland cats would be taxonomically appropriate for potential reintroduction—good news given that this is the species in the international zoo breeding program led by the National Zoo’s JoGayle Howard. 
Thailand Clouded Leopard Consortium
On the other hand, rapid, widespread habitat destruction on Sumatra and Borneo means that the new species is likely in serious trouble. Moreover, there is no zoo breeding program for this species yet.
References
Buckley-Beason, Valerie A., Warren E. Johnson, Willliam G. Nash, Roscoe Stanyon, Joan C. Menninger, Carlos A. Driscoll, JoGayle Howard, Mitch Bush, John E. Page, Melody E. Roelke, Gary Stone, Paolo P. Martelli, Ci Wen, Lin Ling, Ratna K. Duraisingam, Phan V. Lam, and Stephen J. O'Brien. 2006. Molecular evidence for species-level distinctions in clouded leopards. Current Biology 16:2371-2376.
Kitchener, Andrew C., Mark A. Beaumont, and Douglas Richardson. 2006.
Geographical variation in the clouded leopard, Neofelis nebulosa, reveals two species.
Current Biology 16:2377-2383.
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