Eleven and a half years ago, I traveled to the rugged West Kunlun mountain range, located in northwestern China’s Xinjiang Uyghur Autonomous Region, to survey the calving ground of the chiru, or Tibetan antelope. With only around 75,000 wild chiru remaining, this elusive species — distinguished by its tapering, pointed antlers and thick, fluffy, white-brown fur — is officially classified as “near-threatened” by the International Union for Conservation of Nature.

West Kunlun is home to the calving grounds of the chiru’s western Changtang population, named after the vast nature reserve in which the animals roam. From late May through early June, thousands of female chiru — some still juveniles, some already pregnant — make the arduous journey northward into the mountains. That summer, we positioned our makeshift tents in the land basin where the animals congregated and spent day after day peering through our binoculars, hoping to catch a glimpse of them. The sun sets late in Kunlun; we would set out each day around 8 or 9 in the morning and wouldn’t return to our tents until the same time that evening. Often, while climbing over ridges or turning into valleys, we would happen upon little groups of chiru grazing peacefully, occasionally even finding ourselves practically face to face with one.

Chiru calves start to appear in mid-June. Young chiru have two ways of protecting themselves from danger: Either they will bolt away with their mother, or they will lie completely still and try to blend in with the rocks around them. We attached wireless collars to 12 of these “rocks,” and planned to monitor them around the clock. That way, we would learn how much time they spent on the hoof and at rest — back then, we lacked even this basic information about their habits. It was no use, though: The chiru ran far too fast, and we soon lost their signal.

In early July, heavy snows force the chiru out of the nearby valleys and into the basin itself. Standing in the center of the basin, we once counted 2,400 chiru through our binoculars. The chiru’s calving period peaks between late June and early July each year. Coordinated births are another of the species’ natural defenses against predators: If a wolf comes across a herd of calves, it can only snatch one or two at most, while the others escape. After giving birth to their young, the chiru head back to where they came from, perhaps responding to some kind of group-triggered signal saying it’s time to return south.

After leaving West Kunlun, the herd moves south through narrow passes and valleys before finally reaching the Aru Basin in mid-August. Such basins are classic features of the Changtang region of the plateau. A saltwater lake lies in the middle, surrounded on all sides by a ridge of snowcapped mountains. The local wildlife lives on the grassland lying between the mountains and the water. Around 20,000 to 30,000 chiru live in the Aru Basin, converging on their respective rutting grounds to mate when the cold winds of December start to blow. The following May, pregnant chiru females will once again head north to Kunlun, in a cycle that has continued for thousands of years.

The chiru’s migratory pattern was first described in 1992 by world-renowned field biologist Dr. George Schaller, and their route and calving grounds were confirmed once and for all by four American climbers in 2002. The survey we conducted a decade ago showed that about four to five thousand female chiru used this calving ground. Of these, 40 percent successfully produced offspring. Its range covers a staggering 1,600 kilometers, from Changtang to Hoh Xil — a blue-hued ridge on the Qinghai-Tibet border known to Tibetans as the “Lord of Ten Thousand Mountains.” A different, nonmigratory chiru population has made its home in southern Changtang.

Schaller spent the period from the mid-’80s to the mid-’90s meticulously working out the chiru’s population distribution, as well as their migratory route and a rough estimate of their numbers. At this time, the chiru were frequent targets for poachers. Fortunately, from 1993 to 2003, the Chinese government created a series of nature reserves in western Qinghai and northern Tibet, including the Changtang, Hoh Xil, West Kunlun, and Mid Kunlun regions. Together they covered most the chiru’s traditional area of activity. At the same time, the government also launched a concerted and largely effective crackdown on poaching.

Today, poaching has been almost entirely eliminated in the region, but new problems have arisen in its place. From 2005, grazing contracts were issued to farmers in the Aru Basin, and large tracts of land were fenced off. These fences trap and kill chiru, not to mention prevent them from completing their migration. This has led us to focus attention on the impact that the fences and livestock will have on chiru populations.

To try and answer this question, I conducted a comparative study of two basins located in eastern Changtang’s Shuanghu and Nyima counties between 2005 and 2009. Both basins have an area of about 5,000 square kilometers, but the northern basin has comparatively fewer livestock and fences. I conducted several surveys of the wildlife in the two areas, not only on the chiru, but also on wild yaks, Tibetan gazelles, kiang, and other endemic grazers. My findings showed that wild ungulates — the group of mammals to which the above animals all belong — were outnumbered by livestock by a factor of 3-to-1. In the south, kiang — a large wild ass native to Tibet — made up 99 percent of the remaining local wildlife. I was unable to document a single chiru or wild yak.

We must heed these warning signs. The southern basin was home to both chiru and wild yaks as late as the 1980s, and chiru still roam both sides of the basin to the north. I cannot say for sure whether chiru and wild yaks have completely disappeared from the southern basin, but in several years of fieldwork I have yet to encounter any. This does not bode well for the survival of local wildlife: First an animal disappears from one area, then another, and before long it becomes fully extinct. As the chiru and wild yak are both extremely sensitive to human activity, the development of basin areas should set off alarms for conservationists everywhere.

My findings are far from an isolated phenomenon. In the ’80s and ’90s, chiru still roamed in Yeniugou, an area on the West Kunlun’s northern slopes whose name literally translates as “Wild Ox Ravine.” However, none have been seen there since 2002. While the central and northern parts of the territory occupied by the migratory chiru remain undeveloped, there has been a steady influx of people since the ’50s and ’60s, and now chiru share their grazing lands with livestock. How to balance the economic needs of herders and the need to conserve the chiru is perhaps the most pressing question facing those who want to ensure this majestic animal’s survival.

To me, the only way to secure the chiru’s future is to guarantee that the remaining unpopulated regions do not become territory for grazing. Additionally, we must place an upper limit on the number of livestock in southern Changtang and remove fencing from areas known to be critical chiru habitats. If we can accomplish these first steps, perhaps we will ensure that the chiru does not fall victim to human development in China like so many other large mammals before it.

(Header image: Several chiru run alongside the Qinghai-Tibet highway, Hoh Xil, Qinghai province, June 5, 2015. Wen Zhenxiao/VCG)