Yaks’ extensive presence in the snow-clad alpine and subalpine Himalayas makes the landscape look like a crumpled white sheet punctuated with shaggy black dots. And, in the cradle of these mountains, depending entirely on yak produce — milk, fur, skin, dung, and meat — pastoral communities like the Brokpa, a semi-nomadic tribe belonging to the northeastern Indian state of Arunachal Pradesh that borders China, Bhutan, and Tibet, have thrived. But these totemic animals of the Himalayas and their Brokpa herders are increasingly being affected by climate change — and this has forced them to change their traditional ways of being.
Yaks live at altitudes of 2,000 to 5,000 meters above sea level and are comfortable at an average temperature below 10 degrees Celsius. A flagship species for the high rangeland ecosystem of the Himalayas, they are cold-adaptive and are rightly dubbed “shaggy barometers of climate change.” Temperature-driven shifts in wild yak grazing ranges and distribution patterns in the Tibetan Plateau, as well as changes observed in the Brokpa yak pastoral practices, are indicators of a changing climate in high Asia, researchers contend.
Temperatures are rising in the Himalayan yak range, with a projected mean annual temperature increase of between 2.2 and 3.3 degrees C by 2050. A University of Wisconsin-Madison study in 2014 found that in the eastern Tibetan Plateau, daily low temperatures have increased in the past 24 years, and daily high temperatures have increased at a rate of 5 degrees C over a period of 100 years.
“The Brokpa yak pastoralists are facing multiple challenges like temperature rise, degradation of high-altitude pastures, dwindling of the pure yak population, and a gradually shortening winter,” said India’s National Yak Research Centre’s Sanjit Maiti, who studied Bropka herders’ traditional strategies of coping with changing climatic conditions. “They’re responding to the changes in climate by modifying their transhumant yak herding practices.”
According to Maiti, Brokpa climate adaptation strategies include the proliferation of yak-cattle hybridization, migration to higher altitudes, herd diversification, changes in the migration calendar, changes in pasture utilization practices and the rejuvenation of degraded high altitude pastures, feed supplementation, and adoption of modern healthcare.
Adjusting to a changing climate
Sixty-five-year-old Brokpa Phurpa Saiya of Mandla Phudung Village in Arunachal Pradesh has been living the life of a transhumant yak rearer (meaning he follows a seasonal migration pattern from lowlands to mountains) since he was barely ten. He now owns 45 yaks and dzomos, a hybrid of yak and highland cattle called kot. His grandfather Brokpa Tsering was from Monyul – in the Tawang region of Arunachal Pradesh — and he too was a yak pastoralist.
Like other Brokpas, Phurpa also starts his summer hike along with his herd of yaks and sheep in April, as snow starts to melt, baring the high-altitude meadows on which the herd feed. His final destination is Saiya, a grazing range at around 4,500 meters above sea level (masl) on Arunachal Pradesh-Bhutan border. Phurpa’s transitory life continues throughout the summer till late November when, with the onset of winter, he descends back to Mandla Phudung. In the winter, Brokpa yak rearers stay in their permanent settlement area at an altitude around 2,000 masl to 3,000 masl.
“Earlier we used to embark on the upward journey in late May or early June. But now you can’t do that,” he explains. “The yaks start feeling uncomfortable as early as late February because of the heat. The summer has extended and the temperature risen.”
Phurpa says the period of migration has extended by one and a half months in recent years “because winter has shortened.” Also, according to Phurpa, fodder along the route to Saiya has declined over the years, including Paisang leaves (Quercus Griffithii), yak’s favourite winter food.
Brokpa Lobsang, another yak rearer from Arunachal Pradesh’s Tawang district, is allowing the proliferation of yak-cattle hybrids, as hybrids like dzomo are more heat-resistant and can better adapt to lower altitudes and rising temperatures. “But the problem is,” says Lobsang, “if the calf is a dzo or a male born out of a male yak and a female Kot, it’s useless. A dzo is sterile and can’t be used as a bull for breeding purposes.”
Lobsang, nevertheless, plans to shift entirely to yak-cattle hybrids in case climate difficulties soar. Phurpa, on the other hand, says “nothing can be like pure yaks. To me yaks are more than animals. Brokpa identity is based on yaks. A Brokpa must own yak no matter what. Dzomos can only give you milk.” He is ready to migrate to higher altitudes for his yaks’ comfort rather than opting for hybridization. Yaks in the wild have also been affected by climate change. Mother yaks are more vulnerable to climate change affects, Wildlife Conservation Society and University of Montana researcher Dr. Joel Berger told ScienceDaily, as they are likely to climb steeper and steeper terrain in search of snow, which is essential for milk production.
Climatic change or political barriers?
However, the biggest problem Phurpa’s yak herd is facing at present is inbreeding — not climate change. In fact, all yaks outside the “pure yak region,” now in the Tibetan Autonomous Region (TAR) of China, are “thought to be suffering from inbreeding due to the lack of availability of new yak germplasm from the original yak area during the past few decades, and the resultant practice of prolonged use of the same bull within herds,” notes a 2016 report by the International Center for Integrated Mountain Development (ICIMOD).
The wild “pure breed” yak population is estimated at no more than 10,000 to 15,000 individuals, of which nearly the entirety is in China-controlled Tibet, where border controls are strict. The free-crossing of yaks and their herders has thus been restricted. Worse still, yak herds usually have very few males — they tend to live in isolation outside the mating season. And the blocking of yak traffic with the “pure yak region” has caused a serious paucity of yak males outside Tibet when it comes time to mate.
- THE DIPLOMAT
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