IN THIS AGE OF the Anthropocene, as humans overuse landscapes and resources, we are placing increasing pressure on the species with whom we share complex, multispecies ecologies. The flow-on effects from a changing climate have led to unexpected consequences, including the emergence, or re-emergence, of lethal diseases. It is difficult for epidemiologists to pinpoint the exact origins of viral emergence, such as in the case of COVID-19. When viruses and bacteria have an ability to cross species barriers, they are known as zoonoses, often crossing from both domestic and wild mammalian species into humans. Although mammals are recognised as the carrier species for many zoonotic diseases, there has been little attention on the implications of the multispecies entanglements between herding families and the animals they live among in pastoral contexts.
A mobile pastoral approach to health and illness is based on daily herding practices including the care, nurturing, and movement of animals, while oriented towards the prevention of illness and disease.1 The pastoral lifestyle of many herding families across the Mongolian Plateau (which includes peoples of Mongol heritage in Mongolia, the People’s Republic of China and Russia) not only provides a wealth of practical experience of the nurturing and medicinal treatment of herd animals under extreme environmental conditions, but also exposes both humans and multispecies herds to deadly zoonotic diseases, including different forms of influenza, anthrax, brucellosis, tick-borne diseases, rabies, and the plague.2
Different places around the world are affected by climate change in different ways. The Australian continent, for example, is experiencing high temperatures and increasingly frequent droughts, resulting in extreme fire events, such as the devastating Black Summer bushfires of 2019–2020. Herding communities across Inner Asia are experiencing extreme weather events, too, but in the form of devastating snowstorms and fluctuating winter conditions, resulting in the widespread death of herd animals — a phenomenon known to Mongols as dzud. This occurs when there are rapid fluctuations in temperature, resulting in a thick layer of ice forming on the ground. Herd animals are unable to feed on the dried stalks of grass beneath the snow and ice that they rely on to get through the winter. Dzud has historically been recorded in a cyclical pattern every five to seven years on the Mongolian Plateau. With climatic warming of 1–2º Celsius, herders have been dealing with the consequences of dzud on a more frequent basis, particularly if there has been drought the previous summer.3 When whole herds perish, herding families have no choice but to abandon their way of life and make the difficult move into urban centres, with few prospects for a prosperous future.4 This change to more extreme climatic conditions inevitably alters the dynamics of the grassland steppe ecosystem and the multiple species that live on it.
One such implication of climate change is the re-emergence of anthrax as a lethal zoonotic disease across the Mongolian Plateau. In the mountainous regions in the past, the ground remained frozen as permafrost throughout all seasons. But with unusually high temperatures in summer in recent years, the permafrost has begun to melt. In Siberia, the intact remains of Ice Age creatures have emerged from the melting permafrost, including woolly mammoths, sabre-toothed cats, and cave bears.5 All are remarkably preserved, even still possessing thick coats, despite having been extinct for thousands of years. In one instance, in Russia in 2016, a 75-year-old reindeer carcass melted out of the permafrost, releasing deadly anthrax bacteria into the surrounding soil. This then struck down a reindeer herd grazing nearby and subsequently infected herders who were tending them. The outbreak resulted in the death of a twelve-year-old Nenets boy.6
The grassland ecosystem in Mongolia is remarkably intact compared with much of the rest of Eurasia, with both domestic and wild ungulate species roaming free and with the potential to come into contact with one another — and with humans. Mongolia is home to one of the last places where gazelle can be sighted on the grassland steppe, although the population has been declining rapidly. Their migration routes cross the border between Mongolia and Inner Mongolia in China, but they are increasingly subject to hunting pressure on both sides of the border. Herds of gazelle share the grassland steppe with multiple species of herd animal, including horses, cattle, camels, sheep, and goats. Anthrax has been resurfacing in gazelles, leading to contaminated soil that then infects domestic herds grazing on the same grassland. This results in herding families becoming infected, too.7 The recent re-emergence of cases of anthrax is an indication of how changes in soil conditions on the grassland steppe, hastened by climate change, have set off a cascade of impacts on other species, including pastoral families who rely on the grassland steppe for survival.
The emergence of COVID-19 in Wuhan in China has sparked a heightened global awareness of the health and ecological risks associated with intensive industrial agriculture and the flow of multiple species across borders. Severe Acute Respiratory Syndrome (SARS) and coronaviruses were likely to have existed previously in bat colonies but then spilt over into another species — possibly threatened pangolins, civet cats or ferrets — as secondary hosts, which then inadvertently came into contact with the infected bats and subsequently humans through the trade in these vulnerable species across international borders.8
Like the later global spread of the coronavirus via humans flying on airlines, migrating birds, such as ducks and geese, also spread new forms of influenza. In 2009, avian influenza (H5N1, or bird flu) was recorded in waterfowl migrating along the Central Asian Flyway. First, birds in South Asia became infected, then later, these same infected birds were identified on a lake in Qinghai in China. Through satellite tracking of these tagged wildfowl, researchers subsequently located the infected birds after they had died in the vicinity of remote freshwater lakes as far north as Mongolia and Siberia.9
Through gene reassortment, influenza viruses can recombine and mutate into new, more virulent forms, emerging in different carrier species.10 Unfortunately, new strains of influenza have increasingly been found in pigs, ducks, and chickens raised in cramped conditions on huge, industrial-scale farms in China. Meat production is an important part of the Mongolian economy, but for the consumption of chicken and pork by urban residents, the country relies largely on imports from neighbouring China. Consequently, Mongolia has had cases of swine flu (H1N1) through trade across the border, with some lethal cases in humans in the capital of Ulaanbaatar as recently as 2019.11
A highly infectious respiratory disease, equine influenza, occasionally surfaces with outbreaks in horses and camels in herding encampments across Inner Asia. Genetic recombination of this influenza strain could potentially result in dire consequences for biologically and culturally significant equid and camelid populations.12 The threat extends to closely related endangered species protected within conservation reserves in Mongolia and China, such as the wild horse (Przewalski’s horse, or takhi), wild ass, and Bactrian camel — all vulnerable populations with unique genetics.
In Mongolia, multispecies herds are largely self-sufficient, free-ranging and mobile, while the herding community has retained long-held philosophies about health and traditional forms of medicinal treatment across species and generations. Confronted by the threat of the re-emergence of ancient zoonotic diseases, such as anthrax, or new virulent forms of coronavirus and influenza, there is a public need to recognise that these zoonotic diseases have a cascading effect on biocultural communities, particularly remote, rural herding communities that are the most sparsely populated on the planet. What happens over the border in China, where animals are intensively managed, inevitably has far-reaching consequences for rural communities and the surrounding ecology across Inner Asia. The zoonoses narratives within this piece exemplify the need to think beyond country and species boundaries to reorient our focus towards the wide-ranging, human-induced ecological impacts across species and habitats with the accompanying consequences for interspecies health and well-being. With the ability of herding families to exist with potentially lethal zoonotic diseases and their adaptation to extreme environmental conditions over thousands of years, through mobile and free-ranging methods of managing multiple species, there is the potential to learn from this different way of living in a rapidly changing world.