The vast rangelands that cover the steppes, deserts and plateaux of Central Asia and Tibet harbour 12 species of large herbivores (Table 1), not including five caprins that occur in the high mountains that fringe and intersect the area. They include the ancestors of several domestic animals and three migratory or nomadic species, each one integral to, and emblematic of, the three major rangeland ecosystems in this region. These are: Mongolian gazelle on the Daurian steppes of eastern Mongolia, China (Inner Mongolia) and Russia; chiru on the Qinghai–Tibet Plateau, and saiga antelope in Central Asia, extending west to the pre-Caspian steppes on the southeastern edge of Europe.
Table 1. Large herbivores in Central Asia and the Qinghai–Tibet Plateau and 2008 Red List status
|Species|| ||Red List status (IUCN 2008)|
|Przewalski's horse||Equus ferus przewalskii||Endangered (EN)|
|Kiang or Tibetan wild ass||E. kiang||Least Concern (LC)|
|Asian wild ass||E. hemionus||Endangered (EN)|
|Wild camel||Camelus ferus||Critically Endangered (CR)|
|Wild yak||Bos mutus||Vulnerable (VU)|
|Chiru or Tibetan antelope||Pantholops hodgsonii||Endangered (EN)|
|Saiga antelope||Saiga tatarica||Critically Endangered (CR)|
|Mongolian gazelle||Procapra gutturosa||Least Concern (LC)*|
|Tibetan gazelle||P. picticaudata||Near Threatened (NT)|
|Przewalski's gazelle||P. przewalskii||Endangered (EN)|
|Goitered gazelle||Gazella subgutturosa||Vulnerable (VU)|
|White-lipped deer||Przewalskium albirostris||Vulnerable (VU)|
Numbers and ranges of all species have declined, some severely. Nonetheless, eastern Mongolia remains one of the very few places outside east and southern Africa where herds containing many thousands of antelopes can still be seen (Olson et al. 2009). At the other end of the scale, wild camel (Hare 2008) and Przewalski's gazelle (Jiang et al. 2000; IUCN SSC Antelope Specialist Group 2008) survive as tiny remnant populations in small fractions of their former ranges. Przewalski's horse became extinct in the wild around 1969 and free-ranging animals are currently restricted to three reintroduced populations in Mongolia (Boyd et al. 2008).
These species are disproportionately threatened. Nine (75%) are listed in a threatened category in the 2008 Red List (IUCN 2008), compared to 25% of all mammals for which adequate data are available (Schipper et al. 2008) and, for example, 25% of all antelopes. Almost all qualify for threatened status under criterion A, based on recent and/or predicted population declines, illustrating a recent and widespread deterioration in their status during the last 15–20 years. This period coincided with widespread economic and social changes across the region that were especially significant for herding communities.
Hunting (i.e. over-harvest) is cited as the main or an important causative factor in the decline of virtually every species. All have traditionally been hunted for meat, skins, and medicinal or other products. The destructive potential of unregulated hunting steadily increased during the latter half of the 20th century owing to increased availability of semi-automatic firearms and four-wheel drive vehicles that give easy access to the open terrain. Hunting intensified still further in ex-Soviet Central Asia and Mongolia when a number of factors coincided following the break-up of the Soviet Union in 1991. The subsequent economic crisis impelled people to further accelerate exploitation of natural resources, a collapse of protection systems removed existing controls, and opening of borders with China facilitated international trade. The most striking example was an explosion of saiga poaching, for the horns of the males and for meat, causing a catastrophic decline in numbers and skewed sex ratios to a point threatening reproductive collapse (Milner-Gulland et al. 1995, 2005).
Chiru are killed for their fine underfur (shahtoosh) which is exported to Kashmir to be woven into shawls. Hunting increased, and chiru numbers fell, through the 1990s; since then, action by the Chinese government and international campaigns to curtail hunting and the illegal trade have had some success and chiru numbers seem to be recovering (Schaller, 1998; IFAW/WTI 2001; Leslie & Schaller 2008). Confiscation of all herders’ guns across much of western China has further lowered the incidence of hunting (Harris 2008).
It is perhaps instructive to look south across the Himalaya to India where four antelopes, three of them not threatened, survive in good numbers despite the pressure for living space alongside 1·2 billion people (Rahmani 2001). Antelopes are protected in part by religious sentiment, but it is surely no coincidence that levels of hunting in India are very low, and gun ownership is rare.
Habitat loss and habitat degradation are also heavily implicated in many declines and occur in various forms: conversion to agriculture, expansion of settlements, industrial development and mineral exploration. Human populations have increased, along with numbers of domestic livestock and associated land use, throughout the region. In Mongolia, for example, the number of herders has doubled since 1991 and livestock numbers also increased (Reading et al. 2006). The result is more competition for grazing, a reduction in plant biomass available for wild herbivores, pasture degradation through overgrazing, disturbance by people and dogs and greater risk of disease transmission. Hybridization with domestic varieties is a real threat to wild camel, wild yak and Przewalski's horse (Boyd et al. 2008; Hare 2008; Harris & Leslie 2008).
Development of infrastructure such as roads, railways, pipelines and major irrigation canals may disrupt movement patterns and exacerbate fragmentation of habitats. The Ulaanbaatar–Beijing railway line has been fenced to prevent livestock from straying onto the track, thus preventing movement between Mongolian gazelle populations living east and west of the railway (Lhagvasuren & Milner-Gulland 1997). Exceptionally, these features may be a direct threat; for example, Zhirnov (2001) reported that 14 000 young saiga drowned in an irrigation canal in 1977. A phase of such developments took place in Central Asia during the 1970s–1980s. Road construction has steadily opened up new areas to livestock grazing, encroaching on previously undisturbed refuges, most recently in Chang Tang in northern Tibet (Schaller 1998; Fox & Bårdsen 2005).
A major phase of economic investment and infrastructure development began more recently in western China with the launch of the Great West Development Plan in 1999 (Harris 2008) which has potentially far-reaching implications for conservation. A growing demand for raw materials means that mineral exploration and mining throughout the region are sure to increase. Mineral extraction and pipeline construction are threats to the remnant wild camel population in the Gashun Gobi, China (Hare 2008).
Major changes in herding and in grazing practices have occurred, with different starting points and trajectories in Central Asia–Mongolia and China, respectively, but with broadly similar results. The acute economic crisis affecting the former USSR and Mongolia from about 1991, referred to above, was linked to withdrawal of state subsidies and an abrupt transition to a market economy. Collective herds were transferred to private ownership and systems of regulated grazing and seasonal use of pastures broke down, livestock numbers increased and tended to concentrate on the most productive pastures.
In China, herding collectives have been replaced by family ownership of livestock and rangeland has been rented to groups of private individuals. The consequence is modification of traditional seasonal grazing patterns in favour of year-round grazing at one location; fixed-site grazing is further encouraged by a growing preference for houses instead of tents, in part to take advantage of educational and health facilities (Miller 2000; Banks et al. 2003; Harris 2008; Leslie & Schaller 2008).
One adverse consequence for wildlife is the introduction of pasture fencing, which compartmentalizes rangeland and hinders movement of wild animals (Miller, 2000). The high density of fencing around Qinghai Lake is the main threat to Przewalski's gazelle, preventing access to the best forage, disrupting breeding and even causing direct mortality (Jiang et al. 2000). Extension of this policy more widely will potentially have a serious effect on several species.
All these pressures act in addition to natural factors such as severe winter conditions (dzud), droughts, snowstorms and disease outbreaks, all of which may cause mass mortality. Many chiru (and domestic livestock) died as a result of a major snowstorm in Qinghai in 1985 (Schaller & Ren 1988). Sokolov & Lushchekina (1997) reported a mass die-off of Mongolian gazelles due to foot- and-mouth disease in 1963–1964 and another major disease outbreak occurred in 1998 (Schaller & Lhagvasuren 1998).
The synergistic effects of combinations of threats acting and interacting together are unknown. One negative consequence of all the above threats is an increase in fragmentation, with smaller patch sizes being intrinsically more susceptible to extinction, increased perimeter-to-area ratios reducing the size of undisturbed core areas, and extended inter-patch distances restricting gene flow between subpopulations. Another insidious but unquantified potential threat is the loss of intraspecific variation, as alleles, and perhaps co-adapted gene complexes, disappear as local subpopulations are extirpated.
The lower prey biomass represented by depleted herbivore numbers certainly affects predators, while changes to vegetation composition and structure surely have as yet unstudied consequences for grassland ecosystems. Local extirpation of goitered gazelles was a factor in the regional extinction of the cheetah Acinonyx jubatus in Central Asia, and lack of a prey base is a major obstacle to its reintroduction (Mallon 2007).
Protected area coverage is uneven. A series of extremely large reserves totalling more than 600 000 km2 extends west–east across the Qinghai–Tibet Plateau and encompasses most of the known chiru lambing sites (Leslie & Schaller 2008). Two important reserves in Russia protect the westernmost saiga population. On the other hand, only a very small number of the Endangered Przewalski's gazelle occur within a reserve and Mongolian gazelle range is also poorly covered by protected areas. Some designated protected areas exist only on paper and others lack capacity and full effectiveness.
On the positive side, most of these herbivores (except wild camel) have rapid reproduction rates and their numbers can quickly increase if direct persecution is lifted. The decline in the saiga population has at least stabilized (CMS 2006). A recent major project to conserve saiga and steppe bird communities in Kazakhstan provides an excellent example of multi-partner cooperation involving several NGOs, academic institutions, and government agencies. Collaborative work on saiga has been further facilitated by formation of the Saiga Conservation Alliance and regular publication of ‘Saiga News’ in several languages.
Useful technical developments include improvements in satellite imagery, remote sensing and spatial data analysis using GIS, as well as advances in satellite collaring technology that enable more accurate data on animal movements and habitat use to be generated.
There is still a need for basic data on some aspects of species’ ecology and extent of overlap and competition with domestic livestock. Accurate and reliable estimates of population size and density using rigorous statistical methodology are frequently problematic because of clumped distribution and unpredictable movements over large ranges. Standardized monitoring protocols based on robust sampling design that can track population trends and differentiate genuine declines due to anthropogenic impact from the background ‘noise’ of natural population fluctuations are needed for several species. Hopefully, satellite images of sufficiently fine resolution (most probably already in use in military applications) that would allow remote identification and counts of species to be made over wide areas, will soon become available for civilian use.
An immediate task is to prevent the extinction of the most highly threatened species with very low population ceilings, such as wild camel and Przewalski's gazelle. Neither of these has a meaningful captive population, and therefore, their complete extirpation is a real possibility.
Reserves are essential to protect critical sites and populations although they are more effective when embedded in wider strategies. For most species, ambitious, landscape-level programmes incorporating a wide range of proven and innovative measures are needed that cover spatial scales adequate to conserve fully functioning ecosystems where herbivores and predators can coexist and interact over the long term. This is a challenging endeavour, especially for nomadic and migratory species with large variations in seasonal habitat use. It is, however, still feasible while relatively substantial populations are still extant and extensive tracts of grassland remain intact and undisturbed. It is vital that the opportunity to conserve these unique herbivore communities is not lost or further delayed.
Human presence in and around rangelands will inevitably increase, as will demands for consumptive use of species, grasslands and mineral resources, and pressure for further ‘development’. Conservation strategies have to address these issues and work with pastoral communities to agree on shared use of rangelands and levels of offtake that are sustainable in the long term, strategies that are of mutual interest and benefit to conservationists and pastoralists alike. Research on the types and extent of human land-use, peoples’ expectations and their perceptions and valuation of biodiversity, will be as important as ecological research, and preferably carried out with the involvement of social scientists and anthropologists, as advocated by Adams (2007 and references therein).
China has a key role in the conservation of these species. All 12 species formerly occurred there; 10 still occur and there are plans to reintroduce the other two. Six of these species (chiru, wild yak, Tibetan gazelle, Przewalski's gazelle, kiang, white-lipped deer) are either endemic to China or > 95% of their population occurs there. China is also vital to the survival of the wild camel, as the Chinese population is the only one not subject to hybridization with domestic camels (Hare 2008). China's importance extends further to its role as a major consumer, notably of saiga horn and other products for the traditional medicine market. Measures to regulate demand should be integral components of wider conservation programmes.
Hovering above all is the spectre of global climate change. The overall trend towards warmer conditions is clear but site-specific and local effects on vegetation and ecosystem productivity and the time-scales over which these may operate are not immediately predictable, emphasizing the need for adaptive management and flexible conservation strategies.