The tiger: a sad tale of declining numbers
International Tiger Day, also known as Global Tiger Day, is an annual celebration held annually on 29 July. The initiative of the Saint Petersburg Tiger Summit, the day raises awareness of tiger conservation, promotes opportunities for discussing the tiger’s natural habitats, and encourages support for ongoing conservation efforts. Ahead of International Tiger Day this Sunday, we take a look at the threats tigers face today with this amended extract from The Encyclopedia of Mammals.
From the villainous Shere Khan in Kipling’s Jungle Book to the protective “guardian of the west” of Korean mythology, tigers play a more vivid role in the human psyche than perhaps any other animal. Latterly they have become a symbol for conservation, and their survival on the planet has come to represent the human struggle to balance our conflicting needs and desires.
The “Tyger, tyger, burning bright” of William Blake’s famous poem is growing dim. Of the nine recognized subspecies, the three smallest and most isolated are now extinct. The Bali tiger was the first to go – the last reliable sighting was in 1939 – followed by the Caspian and Javan tigers, last seen in 1968 and 1979 respectively. Today, South China tigers are considered to be functionally extinct in the wild by many scientists, and all the others are severely threatened. The best available figures suggest that tiger numbers worldwide declined from perhaps 100,000 at the beginning of the 20th century to approximately 5,000–7,500 at its end. Current estimates of the surviving populations suggest around 1,850 Bengal tigers left in the wild, along with an estimated 500 Malayan tigers, 450 Amur tigers, less than 400 Sumatran tigers, and 300 Indo‐Chinese tigers.
Surviving tigers face three main threats: direct poaching, habitat loss, and prey depletion. The growing demand for tiger bones for traditional Asian medicines, and for skins as trophies, has resulted in ever‐growing losses. The greatest exporter of tiger‐bone products is China, which distributed over 27 million items from 1990 to 1992. Japan, Hong Kong, and South Korea are the largest importers: South Korea took delivery of nearly 9,000kg (20,000lb) of tiger bone between 1970 and 1993. Attempts to control this illegal trade have had results, but it remains substantial.
The threat to habitat comes from the degradation and fragmentation that ensue as human populations grow. As tiger populations become isolated and reduced, the fragmented remnant populations grow increasingly susceptible to extinction. Inventive land‐use plans have been proposed for such countries as Nepal, Thailand, and Russia, seeking to link protected areas via a network of conservation units and ecological corridors that aim to maintain the integrity of entire metapopulations. Such schemes have become more effective with the use of geographic information systems (GIS) that rely on remotely sensed satellite imagery and allow analyses of multiple elements of the landscape, including forest cover, prey densities, and human impacts. Successful habitat restoration projects in Nepal provide incentives to villagers in return for the protection of communal lands.
Even if habitat is successfully protected, sufficient prey must be present. Many tracts in Asia that would otherwise be suitable are devoid of tigers today because of a shortage of large ungulates. An adult tiger can eat 18–40kg (40–88lb) of meat at a sitting, and must kill 50–75 large ungulates a year. For those ungulate populations to persist, predation and other causes of death should not account for more than 30 percent of their numbers annually, and in many cases densities are not high enough to support tigers. In other parts of the tiger’s range, prey only survive in sufficient numbers in protected areas; in the Russian Far East, for example, numbers are often 3–4 times higher inside protected zones. Better controls on ungulate harvest in unprotected areas, along with the elimination of hunting in the protected ones, could benefit both tiger and human populations with the potential for a sustainable harvest.
Ultimately, tigers will survive only if local people find it in their interest to preserve and protect them. Local people in many parts of the tiger’s range regard the animal as a compelling and necessary component of their environment, however much they may fear it. Seeking means to meet the needs of tigers and humans in remaining forest tracts will be the key to the animals’ survival.
Adapted from the entry on ‘Tiger’ in The Encyclopedia of Mammals edited by David MacDonald. Copyright © Brown Bear Books 2012. David MacDonald is Founder and Director of Oxford University’s Wildlife Conservation Research Unit.
Tiger goes into the water. Photo by Schnuddel, iStockphoto.