干旱区生态环境知识资源中心

The inherent defencelessness against natural predators of bustards, which have relatively small bills and can neither perch in trees nor take refuge in water at night, renders them warier than other large-bodied birds. They are therefore dependent on large areas of little-disturbed, little-developed open country within which they can see and keep danger at a good distance. In Asia (here including Central Asia and Asian Russia), six species-Little Bustard Tetrax tetrax (IUCN global category Near Threatened), Great Bustard Otis tarda (Vulnerable), Asian Houbara Chlamydotis macqueenii (Vulnerable), Great Indian Bustard Ardeotis nigriceps (Critically Endangered), Bengal Florican Houbaropsis bengalensis (Critically Endangered) and Lesser Florican Sypheotides indicus (Endangered)-are already at serious risk of extinction. Great Bustard (of the nominate race) is struggling to survive in Asian Russia (< 200 individuals), Kazakhstan (100-1,000) and China (maximum 52 seen in extensive surveys, 2014-2016), while in Asian Russia the eastern race dybowskii numbers just 380-430 (with only 5% in protected areas), fewer than 1,000 in Mongolia and 600 in China. Little Bustard is now largely restricted to Kazakhstan and westernmost Asian Russia and, although its status evidently improved in the 1990s with the post-Soviet abandonment of agriculture in Central Asia, re-intensification of farming is poised to cause new declines. Asian Houbara has a population claimed to be between 50,000-100,000 individuals, but is certainly declining despite largescale captive breeding programmes, with one study suggesting an offtake of 27.1% in the years 1994-2008 when the maximum sustainable level was 7.2%, and another indicating a current annual population decline in Uzbekistan of 9.4%. Great Indian Bustard (< 200 birds in the most recent assessments, some in unviable habitat fragments), Bengal Florican (225-249 males estimated for South Asia; several hundred in Cambodia) and Lesser Florican (270 males estimated in 2017 compared with 1,103-1,765 in 1994-1999) are all in extreme trouble. Habitat change, chiefly in the form of rapid and widespread agricultural intensification (mechanisation, chemical applications, overgrazing, increased fencing and new choices of crop), but also involving infrastructure developments and disturbance, is probably the single biggest threat; only the semi-desert-dwelling Asian Houbara remains relatively unaffected. Hunting and poaching is a particularly serious threat to Great and Little Bustards and Asian Houbara, as well as Great Indian Bustard. Powerlines are known to have killed and injured birds of five of the six species and currently are the most serious cause of mortality to Great Indian Bustards, and problems caused by powerlines are anticipated to intensify for all species. Predation, most seriously by uncontrolled dogs, has been registered as a strong negative influence on Great Bustard and seems likely also to affect Little Bustard, Great Indian Bustard and both floricans. The long-term prospects of all six species are extremely bleak unless their conservation is prioritised and significantly strengthened.

Adult survival and productivity are key to the health and recovery of bustard populations and both need to be improved through well-managed nature reserves (organised along flyways for long-distance migrants), plus: special protection of areas where males display and around which females are known or expected to breed; continuous unfragmented landscapes subsidised for low-impact farming with reduced grazing pressure within which the birds’ social dynamics are unconstrained; the strategic planting of crops favoured by all species; strict and strong regulation of both powerlines and fencing within and beyond those landscapes; equally strict and strong control of hunting, poaching, dog predation and inappropriate grass-fires; and sustained campaigns of public awareness and engagement. The model of Castro Verde Special Protection Area in Portugal, where Great and Little Bustard numbers have multiplied and the livelihoods of communities have been supported through subsidy, provides evidence that practical solutions are possible. Detailed cataloguing of records and intensive biological research programmes are also needed for all species, together with support for local conservation groups and scrupulous review of all landscape-related plans to prevent adverse developments. Hunting of Asian Houbara must come under national systems of control based on an internationally agreed strategy. Governments must now prioritise the conservation of bustards as the burden of responsibilities is too great for NGOs to bear alone. International coordination and collaboration will, with high levels of communication, be crucial to success. The setting of time-bound targets is required to spur key staff into rapid action.