Biodiversity

In most countries, overhunting has been the driver of the decline in tigers and their prey [6],[7]. Additionally, loss and fragmentation of habitat was locally important [8]. Nevertheless, beginning in the early 1970s, conservation initiatives helped establish a large number of tiger reserves, particularly in India, Nepal, and, to a lesser extent, in Thailand, Indonesia, and Russia. Probably the most successful of these, at least initially, was Project Tiger in India, which was launched in 1972 with the political support of Prime Minister Indira Ghandi. The apparent success of these reserves prompted, in the 1990s, many conservationists [4],[9],[10] (including some of the co-authors of this report) to shift their focus to a landscape approach, which sought to conserve tigers well beyond protected areas, so as to maintain the genetic and demographic viability of populations of this low-density, wide-ranging species. Conservation investments subsequently increased, but the array of activities was complex, less directly related to tigers, and spread thinly across large landscapes [11]. With hindsight, it also became clear that protection and management of many reserves remained inadequate (the extirpation of tigers in the Indian tiger reserves of Sariska, reported in 2004, and Panna, reported in 2010, is illustrative) and this, coupled with an increased demand for tiger parts [12], meant that poaching of tigers and prey decimated populations across Asia, both inside and outside reserves.

Actively protecting tigers at source sites is feasible and pragmatic, and has been demonstrably successful in many reserves across India between 1974 and 1986 [16]. The Malenad-Mysore tiger landscape currently maintains >220 adult tigers, one of the greatest concentrations in the world, mainly due to intensive protection of its source sites such as Nagarahole National Park, where tiger numbers have increased by 400% after protection began in the early 1970s [17],[18], and has now maintained a high density for 30 years ([19], unpublished data). Across India, tiger abundance is strongly correlated with prey density [20] and both depend on strict controls on hunting. The Tigers Forever program [21] has supported governmental protection effort, aided by MIST (Management Information SysTem) law enforcement monitoring [22], in Thailand, Lao PDR, and Malaysia, and hunting has been reduced and tiger populations stabilized. However, these results require greater levels of law enforcement, surveillance, and monitoring than typically is found in national protected areas. In the Russian Far East, traditionally a stronghold for tigers, annual monitoring detected a dramatic decline in tiger numbers over the last five years, which was associated with a decline in enforcement [23],[24]. Recent declines in tiger numbers in the once thriving source sites in Nepal were also associated with reduced emphasis on protection [25].

Protecting source sites is financially attainable. Our analysis [13] estimates the average cost of protecting and monitoring tigers effectively at all 42 source sites at $82 million per year or $930/km² per year, within the range of effective protected area costs in general (from $130 to >$5,000/square kilometer/year for densely settled regions in Asia) [26]. More than half of these funds ($47 million, almost US$500/km²) is already being committed by range-state governments and, to a far lesser extent, international donors and NGOs. However, much of the total governmental financial commitment comes from and is spent in India. When India is excluded from the analysis, the average current commitment drops to US$365/km² per year. This leaves an overall shortfall of US$35 million a year for all source sites.

However, with so few wild tigers remaining, almost entirely clustered in a few small areas, the most immediate need is to protect populations in the remaining source sites. For financially valuable species like the tiger, intensive protection is paramount, and the success of such protection has been demonstrated. Commitments made at the Russian Summit must refocus on the protection of source sites—a strategy that is financially realistic, politically feasible, and will deliver the greatest return on conservation investments. Only when we are able to stop the slide in tiger numbers at source sites will we be successful at managing tigers across the wider landscape.