YUSHU COUNTY, CHINA — As he gazes out across the rolling grasslands of the Tibetan plateau, where hundreds of his yaks are grazing, 70-year-old Awang Chumpey is less than happy. The land he shares with his neighbors is dotted with thousands of tiny burrows, home to a colony of plateau pika that he blames for eating his animals’ grass.
A smaller relative of the rabbit, the plateau pika occupies an almost identical ecological niche to the United States’ prairie dog. And it is equally unpopular in many rural communities.
“Over the years the grass has become very bad,” Awang said. “They dig holes and eat the grass. I hope the government can kill them.”
Herders like Awang are largely getting what they want. For decades, across hundreds of thousands of square miles of the plateau, a relentless extermination campaign has been undertaken to wipe out the plateau pika, with thousands of people fanning out as spring arrives to poison their burrows. Across vast swaths of grassland, the pika has been virtually eliminated.
Only now are some people in China realizing they may have made a huge mistake — just as some people in the United States have concluded that the mass extermination of prairie dogs might not have been such a great idea after all.
Indeed, the plateau pika is the scapegoat for much deeper, man-made problems, a symptom, some Western scientists say, of decades of environmental mismanagement by China’s Communist Party, which threw out the natural balance that had endured on these grasslands for thousands of years.
Just like the prairie dog, the plateau pika — which has not been wiped out yet, by any means — is what environmentalists call a keystone species, playing a crucial role in the ecosystem that sustains life. And their burrows, it is now believed, play an important role in absorbing the heavy rains that fall during the summer monsoon, allowing water to percolate slowly through the earth rather than cause dangerous downstream flooding and erosion.
“The pika is very important for the food chain and for the grassland ecosystem,” said Hashi Tashi Dorjee, founder of the Snowland Great Rivers Environmental Protection Association and one of the Tibetan region’s most respected environmentalists. “Poisoning them sets off a very bad cycle.”
Here, on the Alpine meadows that carpet most of the Qinghai-Tibet Plateau, almost all the major carnivores depend on pikas for food. That includes brown bears, Tibetan foxes, steppe polecats and Pallas’s cats — small, furry, real-life versions of the Cheshire Cat of “Alice in Wonderland” but with a distinctly wild nature. Upland buzzards and saker falcons feed primarily on pikas, too; one way to spot a pika colony on the grasslands is to look for a buzzard flying overhead or perched on a power pylon.
But as pikas have disappeared from broad stretches of this grassland, so have many of these unique animals, said Andrew Smith, an Arizona State University expert who has been studying the ecology of the Tibetan plateau since 1984.
“For brown bears, what we call grizzly bears in the United States, 60 to 80 percent of their food is pikas,” he said. “Where the pikas have been poisoned, the bears go on the move to search for food, and they have been breaking into Tibetan houses.”
On the largely treeless grasslands, birds such as snow finches and Tibetan ground tits nest in pika burrows. But, where pikas have been poisoned, the burrows collapse within a couple of years and these birds disappear or become scarcer, Smith said.
A pika warren can stretch underground for up to 20 yards and have several small openings from which the nervous animals poke their heads, scanning the grasslands for predators and emitting a faint, high-pitched alarm call at any sign of trouble. Starting in 1962, the government sowed those burrows, first with sodium fluoroacetate and then zinc phosphide, across nearly 140,000 square miles of grassland. In 2006, it stepped up the campaign across huge parts of the vast, newly created Sanjiangyuan National Nature Reserve, now using botulinum toxin.
Justifying the government’s extermination campaign, some Chinese scientists have blamed the pika for grassland degradation and erosion.
But a growing body of Western conservationists say they have it all wrong.
Far from causing grassland degradation, pikas tend to colonize areas where the grassland is already damaged by overgrazing or has dried out as a result of climate change. Not surprisingly, they prefer areas where the grass is short, so they can spot predators from farther away.
“Villagers see the pika, and they see the grassland getting degraded, and they connect the two problems,” Tashi Dorjee said. “They see the surface problem, but they don’t see the root of the problem.”
Rather than causing soil erosion, pika burrows dramatically improve drainage on the plateau, according to a 2014 study by Smith and Maxwell Wilson in the journal Ambio, published by the Royal Swedish Academy of Sciences. Without them, water runoff creates more erosion and heightens the potential of dangerous floods downstream.
Most of Asia’s great rivers originate on the Tibetan plateau, and 20 percent of the world’s population lives in their downstream watersheds.
“The chances of downstream flooding, the chances of loss of life and property, are much greater as a result of this animal having been poisoned upstream,” Smith said.
The Qinghai government boasts of exterminating “rats,” although pikas are not actually rodents. It says yields of grass have improved in areas where pikas have been wiped out. Officials declined requests to be interviewed for this story.
In fact, Western conservationists say, the overgrazing and degradation of the grasslands should be blamed not on the pika but more on the government’s own social and environmental policies, stretching back to the imposition of communal animal husbandry in the 1960s, and to later moves to erect fences throughout the grasslands and resettle nomads into permanent houses.
The parallels with the prairie dog and the European rabbit are striking. Prairie dogs have been widely blamed for eating grass upon which livestock depend, and for building burrows that cause cows and horses to break their legs. A mass extermination campaign brought them to the brink of extinction across much of the United States.
But scientists say that, similar to the pika, they support prairie falcons, eagles, badgers and bobcats, while their presence helps increase the richness and diversity of plant species on the grasslands. Their extermination brought the black-footed ferret to the brink of extinction, with only 18 left in 1986. The extermination of the rabbit from its native habitat in Spain and Portugal has made the Iberian lynx, which depends on European rabbits, the most endangered cat on the planet.
Today, millions of dollars are still spent in the United States killing prairie dogs, and millions more are spent trying to preserve the ferrets that eat them. In China, the establishment of a national nature reserve goes hand in hand with the extermination of a native keystone species.
“It is clear that the antagonism of government and ranchers towards prairie dogs was in part based on purposeful ignorance, even when accurate knowledge was available, and on vested interests in continuing a well-funded killing program no matter how outdated and harmful,” leading conservationist George B. Schaller wrote in his book “Tibet Wild.” “The story of the pika has been remarkably similar.”
Xu Jing and Xu Yangjingjing contributed to this report.