Science

A struggle to co-exist with humans

Free-rangers: Dogs have been noted to prey on saiga, blue sheep, argali and other such ungulates.

Free-rangers: Dogs have been noted to prey on saiga, blue sheep, argali and other such ungulates.   | Photo Credit: guenterguni

Seasonal relocation of agro-pastoralists can impact ungulates

In 1968, when the book, The Population Bomb, was published, there were a little over 350 crore people on Earth. Today, the whopping 750 crore human population has made an impact on most flora and fauna. Taking into consideration this lack of abatement in human population growth, an international team of researchers observes how these ecological disruptions affect the life of ungulates (hoofed large mammals). The team notes that humans have brought about changes in the Himalayan realm – there is an increase in cashmere goats, and also, stray dogs have started hunting ungulates including threatened, endangered, and rare ones such as kiang, chiru, saiga and takin.

Himalaya and Andes

The team also draws similarities between the two giant mountain ranges – the Himalaya and the Andes, both homes to unique ungulate fauna. Both are currently experiencing increased deglaciation, human colonisation, climate alteration, livestock and tourism-induced changes.

A paper published in Frontiers in Ecology and Evolution stresses that the “world’s 400 million free-ranging dogs – through disease, predation, and displacement – have changed the face of ungulate communities on every continent.” Dogs prey on saiga, blue sheep, argali, chiru, kiang, goral, ibex, sambar, chital and blackbuck.

Joel Berger from Wildlife Conservation Society, the first author, witnessed multiple predation attempts on takin and blue sheep in Bhutan. He writes about seeing up to four dogs in 11 attacks of takin; three of nine calves were individually separated from the groups and disappeared. “Their fates remained unknown... death appeared likely.”

The high elevation dogs of Bhutan also harbour tapeworms which when consumed via grasses by yaks can cause coenurosis, a neurological disease that may result in about 10% mortality of young yaks.

Human activities such as the seasonal relocation of agro-pastoralists to collect the worm fungus Cordyceps can also have an impact on the ungulates. These high-elevation environments have experienced minimal direct human disturbance, and this movement can lead to the displacement of native species. Previous studies have shown that many apex predators have been lost due to fear, habitat conversion and loss of prey.

Key issues

The authors write: “Issues of the 19th and 20th century, overharvest, poaching, and wildlife slaughter will not be the most pressing in the 21st century.” Climate change and rapid destruction of habitat will be key. High-elevation ungulates have been known to be affected through changes in ice and snow and the availability of snow patches.

They further add, “Conservation practitioners should work fiercely... to protect what we have while simultaneously recognising that disturbed habitat and altered communities still offer important contributions to beta biodiversity.”

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Printable version | Jul 10, 2020 1:04:35 PM | https://www.thehindu.com/sci-tech/science/a-struggle-to-co-exist-with-humans/article31877630.ece

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