Separated by geography for thousands of years, the clouded leopards (Neofelis diardi ssp. diardi) of Sumatra and the clouded leopards of Borneo (Neofelis diardi ssp. boreensis) are separate subspecies of Sunda clouded leopard (Neofelis diardi). Less than a decade ago, the Sunda clouded leopard was recognized as separate from the clouded leopard (Neofelis nebulosa) of mainland Southeast Asia.
Threatened by illegal hunting for their unique pelts and by deforestation for palm oil plantations, habitat protection and control of illegal wildlife trade will be needed to ensure clouded leopards survive. The separation of the two subspecies increases pressure on both Borneo and Sumatra to safeguard these big cats, as both subspecies are considered Endangered under the IUCN Red List guidelines.
How New Wildlife Species or Subspecies are Determined
Before genetic testing became feasible in wildlife research, differences in the cranio-mandibular portion of the skull and dentition were used to help separate similar species or subspecies. For leopards, the pattern of spots, and in the case of the clouded leopards, the cloud shaped patches within their spots, is also sometimes used to differentiate between species and subspecies.
Today, mitochondrial DNA testing and microsatellite loci, which are repeating DNA sequences, are also used to separate species and subspecies. But even this genetic data may not be definitive. If there are no major differences in these genetic tests, statistical analysis may help in the decision making process but in these cases, the combination of genetics, cranio-mandibular skull morphology and dentition is used to make a determination.
The Case For Two Subspecies of Sunda Clouded Leopard
As Darwin’s finches showed, species and subspecies often evolve differently when they are geographically separated. This appears to be the case for the clouded leopards. Less than ten years ago the Sunda clouded leopard was recognized as a separate species from the big cats on the mainland of Southeast Asia. In 2011, the case has been made for the Sunda clouded leopard to be separated into 2 subspecies (Wilting et al 2010).
The study showed that clouded leopards found in Borneo and those found in Sumatra have enough differences in mitochondrial DNA, microsatellite loci, cranio-mandibular skull morphology and dentition to be listed as separate subspecies. Interestingly, analysis of the spot pattern did not show enough consistent difference to be used as part of the case for separation, however with a larger sample size this may change.
The Importance of the Subspecies Differentiation for Clouded Leopard Conservation
Taken as a whole, the Sunda clouded leopard is listed as Vulnerable under IUCN Red List guidelines. But, each subspecies, taken on its own, is classed as Endangered. Endangered Species listing helps ensure higher levels of protection, as more funding is generally available for conservation of endangered species and the higher profile helps ensure better support for those conservation efforts.
Borneo, which may have a larger population, is already heavily involved in clouded leopard conservation but work in Sumatra has focused on another big cat species, the critically endangered Sumatran tiger subspecies (Panthera tigris ssp. sumatrae). The presence of the tigers may be a factor in the lower density of clouded leopards on Sumatra, as the two species may compete for habitat with the larger Sumatran tiger getting the better real estate.
Endangered species status for the Sumatran clouded leopard will help protect their habitat as well and increase interest in the other endangered big cat on Sumatra. And, while genetic testing has helped advance the science of species identification, the use of camera traps has enabled wildlife researchers to find some of the more elusive, and often, nocturnal species. This has been the case with the Sunda clouded leopards. Using the combined information gained from these two technologies, the chances of survival for the clouded leopards on both Borneo and Sumatra may have improved.
Source:
Andreas Wilting, Per Christiansen, Andrew C. Kitchener, Yvonne J.M. Kemp, Laurentius Ambu, Jörns Fickel. Geographical variation in and evolutionary history of the Sunda clouded leopard (Neofelis diardi) (Mammalia: Carnivora: Felidae) with the description of a new subspecies from Borneo. Molecular Phylogenetics and Evolution, 2010; DOI: 10.1016/j.ympev.2010.11.007
Dawn M. Smith - A vet nurse, Dawn has worked in wildlife rehabilitation and conservation around the world in addition to her veterinary hospital ...
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