Tibet: the wild yak

The wild Tibetan yak (野牦牛) was once widespread across the Qinghai-Tibetan plateau, with an historical range stretching from northern India and Nepal, and throughout the Chinese provinces of Gansu, Sichuan, Qinghai and Xinjiang. It was even found in Kazakhstan, Mongolia and parts of southern Russia until the 18th century, though any real trace of it has long since disappeared. The large traditional range of the wild yak made it an easy target for hunters, especially the male yaks that tend to disperse throughout the plains, rather than the hills and ridges that the females seem to prefer. Hunting through the 1950s to the 1980s eventually pushed the wild yak back to the Qiangtang-Kekexili area, though with the confiscation of guns in the Qinghai-Tibetan plateau, coupled with an increase in protection, poaching and hunting have declined to the extent that it is no longer deemed a threat to populations. In fact, the wild yak population has shown signs of recovery in terms of range, leading it to branch out from Qiangtang-Kekexili – though this has brought wild yaks into contact with the livestock that roam the pastures on the plateau.

Despite these signs of success, the wild yak is still listed as ‘vulnerable’ by the IUCN, which reports that the wild yak population has declined by over 30% in the past 30 years. As with many species of animal in China, the gravest threat to the wild yak is the destruction of their habitat, a consequence of the drive towards economic development, and the subsequent construction, industry, and agriculture that this entails. The increased number of livestock herds on the plateau, as well as the increased intensity of pasture use, has not only displaced the wild yaks away from fertile grasslands, but has also reduced the availability of potential habitat. Wild yaks have a limited tolerance for disturbance from people and livestock, and will move away from areas where livestock is herded; but as livestock herds increase in number and size, so that habitat range of the wild yak is being pressurised into increasingly smaller areas. The gains made in reducing the hunting and poaching of wild yaks has been offset by the agricultural pressures that are exerted on the few areas in China that can handle livestock. China was traditionally a rice- and wheat-producing country, with fertile areas along the rivers being used for its cultivation. Those areas in the West of the country that are now used for livestock were once the preserve of the wild animals that lived there, and the encroachment on and destruction of habit is the gravest threat to China’s wild animals.

tibet-qinghai

For wild yaks, the pressures from agriculture are not limited to just the contraction of their habitat range. Interbreeding with livestock is a threat that is somewhat unique to wild bovines, as it can dilute and weaken the gene pool, as well as precipitate the spreading of diseases, either directly or through other wild species. There were very low numbers of young recorded in the Aru basin of the Chang Tang Reserve in the early 1990s, as well as in the Yalung basin nearby, with only 1.0% of the population comprising young animals, and only a single yearling being seen. This reproductive failure can be indicative of disease, though the IUCN stresses that research remains unclear. There is surely no positive to be drawn from high rates of postpartum mortality, and so whether it is due to disease or other reasons, it does not point to a healthy population. Similarly, interactions between wild yaks and humans rarely lead to positive outcomes, with domestic yaks being abducted into wild herds on occasion, and reports of wild yaks attacking humans and damaging property. This inevitably leads to retaliatory killings, though the IUCN reports these to be rare.

Wild yaks are currently listed as a Class I protected animal in China, and are afforded total protection by the central government. They have been protected in China since 1962 – and their struggles illustrate the difficulties in enforcing protection laws in China – and are also listed on CITES Appendix I. There are nature reserves in China in which wild yaks continue to exist – rather than flourish – including Arjin Shan, Chang Tang, Kekexili, Sanjiangyuan, and Yanchiwan. None of these reserves provide complete protection from habit loss or poaching, and herds continue to move westwards, and become more dispersed and isolated.

***

Sources:

青藏高原野生动物的故事, 19/02/2016 CITES (China),  http://www.cites.gov.cn/ShowIndex/ShowNews.aspx?id=10084&sort=t1

https://en.wikipedia.org/wiki/Tibet#From_1950_to_present

https://en.wikipedia.org/wiki/Yak

http://www.iucnredlist.org/details/2892/0

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