In 11th century China, the scholar Lu Dian wrote an encyclopedia of his country’s beasts, birds, insects, and trees. One of the species he described in the text was a monkey “with fluffy golden tail in the mountains of Sichuan.” Its bones could be used for medicine, he noted, while its skin made good rugs and cushions.
Lu Dian was describing the golden snub-nosed monkey. With its luxurious pelt, bright blue face, and supposed medicinal value, emperors were particularly attracted to this distinctive, nose-less primate, and writers were keen to point out whenever they managed to spot one.
A thousand years later, primatologists are seizing on these mentions of snub-nosed monkeys in Chinese records to reconstruct their historical distribution and show how environmental degradation has heralded the modern decline of this primate across the country. The results were published earlier this year in the journal Diversity and Distributions.
Such an exercise was made possible by China’s 2,000-year-long enthusiasm for systematic record-keeping. These records, which include poetry, gazettes, and chronicles, have been used to reveal historical patterns not only of snub-nosed monkeys, but also elephants, gibbons, and locust outbreaks.
While the ancient texts do not show exactly how many of these monkeys once inhabited China, they illustrate how the species, once widespread, has retreated into ever more remote areas over the years.
The earliest monkey reference comes around the 3rd century B.C., where it is described in the Er Ya encyclopedia as “the odd-nosed animal with a long tail." These earlier records reference monkeys in both lowland and upland areas across eastern, central, and southern China. But over time—and particularly around the 1700 A.D., a time of marked increase in population density—monkey mentions appear in chronicles from increasingly smaller areas of China.
“Over time, you could see this distribution shrinking and shrinking, and then, particularly in eastern, southeastern and central China, they're gone," says Paul Garber, a primatologist at the University of Illinois and co-author of the study.
Today, China's four varieties of snub-nosed monkeys live in remote, mountainous areas in the west and southwest of the country. Even these populations are small and vulnerable: For instance, there are only 800 grey snub-nosed monkeys left in the wild.
Population growth, agriculture, hunting, and deforestation have all adversely impacted the range of snub-nosed monkeys, and have particularly intensified as China's population has doubled over the last 60 years, fragmenting the primate's habitat. Such physical barriers mean that several species are likely to go extinct in the next half-century unless action is taken.
“There are non-human primates in about 90 countries in the world, but most of those countries have very limited economies and very few scholars or scientists,” says Garber. “China is unusual right now….They're at a point they could do something very meaningful to start to mitigate a lot of the environmental disruption.”
The most important action taken to aid the monkeys is the establishment of national reserves, according to Zhao Xumao, a primatologist at the Chinese Academy of Sciences in Beijing who led the work on reconstructing snub-nosed monkey records.
More than 38 national and local nature reserves aimed at preserving the species have been established, and almost every remaining individual from the species currently lives in these reserves. The critically endangered black snub-nosed monkeys, which live on the border with Myanmar, will soon be among that number as the government works to establish the Nujiang Grand Canyon National Park. A master plan for the reserve was approved in 2016.