TIGERS FIGHT FOR SURVIVAL

Loss, fragmentation, and degradation of forests have been the major factors in the decline of the tiger population in this century, with illegal killing playing an increasingly damaging role as tigers have become more vulnerable: no refuges remain safe fro m human penetration. Habitat loss remains a grave danger for the tiger, particularly in South and Southeast Asia. But illegal killing is considered by many conservationists to be the main threat hastening the species towards extinction. Some others believe that the foremost threat to the tiger still comes from habitat destruction.

Illegal Hunting for Medicinal Trade

China's Growing Demand

It can be assumed that within China itself the killing of at least 3,000 tigers as pests in the 1950s and 1960s provided large stocks of bones for medicine factories. Supplies were also likely to have been obtained from poaching of tigers in neighbouring countries such as Myanmar, Laos, and Vietnam, where protective measures have been non-existent. Only in the late 1980s did reports emerge from Nepal and India of poaching for bones and smuggling to China, an indication that stocks were running low in that country and that tigers were becoming more difficult to find in Southeast Asia.

The best data on the tiger bone trade comes from South Korea, where imports were legal and recorded by customs up to 1993. The statistics show that over six tonnes of tiger bone were imported between 1975 and 1992, which could represent the equivalent of 500 to 1,000 tigers (using dry bone weights of 10-12kg per tiger). There was a marked increase in imports in 1988, boosting the annual average through 1992 to 577kg (52-96 tigers a year). Prices over the 18-year period averaged US$127 per kg, with a peak of US$250 in 1987. Nearly two-thirds of the imports to South Korea were from Indonesia, with China second at 14 per cent, probably re-exports. Other listed suppliers were Japan, Thailand, Malaysia, India, Singapore, and Taiwan. In 1991 and 1992, China sup planted Indonesia as the major supplier, but since it had few tigers the products must have originated in other countries. In 1993, as South Korea prepared to join CITES, the country imported its biggest single haul of tiger bones, 1,783kg, representing between 160 and 300 tigers. The vast majority came from China. 

Weak Law Enforcement

Taiwan prohibited tiger bone imports in 1985 and internal sale and possession in 1989. However, tiger products continued to be openly available. Research in Ti-Hwa Street in Taipei in October 1992 found genuine tiger bones in 13 of 50 wholesale shops whic h sold medicinal goods; two had cattle bones labelled "tiger". Prices ranged from US$860 to 1,280 per kg.

Under mounting international pressure, especially from the USA and CITES, China (1993), Taiwan (1994), and South Korea (1994) have all announced bans on trade in tiger bones, and their use in traditional medicines. However, undercover investigators report ed that they had obtained tiger products in various places in China after imposition of the ban. In an unprecedented and controversial move, the USA imposed in August 1994 limited trade sanctions on Taiwan because of its failure to stop the illegal tiger bone trade. The sanctions were lifted on 30 June 1995 on the grounds that "substantial steps" had been taken to halt the tiger product trade.

How effective bans will be in curbing demand remains to be seen. The belief in the efficacy of medicines based on the awesome tiger is ages old and cannot be expected to disappear in the short term. Evidence has been collected that tiger-based medicines a re still widely available despite the announced bans, and illegal trade is likely to continue for a long time to come. That will mean that tigers everywhere will remain under serious threat unless steps are taken to suppress the trade and find effective s ubstitutes. Some practitioners of traditional Chinese medicine have endorsed the use of substitutes and some have expressed interest in collaborative research on substitutes for medicines from endangered species including the tiger.

Poaching and Habitat Loss

Assessing the impact of poaching is difficult. Unlike carcasses of elephants and rhinos, the remains of tigers quickly disappear, particularly when the skeleton has been taken. Skins are easily identified, but few people can distinguish tiger bones from t hose of domestic animals which are used for fertilizer and glue. Where forest guards regularly patrol, they may note that a familiar tiger is no longer to be seen, but it may be difficult to decide whether it was poached or died naturally. In many forests there are too few guards, if any.

Nor is the impact of poaching limited to the loss of the actual animal killed. If it is a female, she is likely to have cubs, who may be unable to fend for themselves, in which case the real loss may be three or four tigers, without counting the loss of t he tigress's breeding potential. When a male is killed, the result may be an intensive struggle among other males to take over the territory during which cubs get killed and breeding is disrupted for a lengthy period, possibly for several years.

The current range of the tiger extends through one of the most densely inhabited regions of the world, where human numbers are rising at an average of 1.87 per cent per annum (i.e. doubling in 37 years), according to the World Resources Institute. Except for Thailand and China (where there are fewer than 100 tigers), human populations are increasing much faster than the average global rate. During the 20 years since Project Tiger began in 1973, India's human population has increased by over 300 million, a nd livestock by over 100 million. In the past 30 years, Vietnam's population has doubled, making it one of the world's most densely populated countries. It is second to another tiger range state, Bangladesh, in terms of farming population per hectare of c ultivated land. The human pressure on wild habitat, including protected areas, is clearly intense, and increasing.

Like other big cats, the tiger probably has little future outside protected areas because of the danger to livestock and human life. Tigers which stray out of reserves and attack livestock are often poisoned by local people. However, this does not necessa rily cause serious damage to the local tiger populations since they are usually non-breeding animals excluded from tiger territories in the reserve. 

The Genetic Threat

Most tiger populations today consist of fewer than 100 individuals and only about 40 per cent of them constitute the breeding population. Inbreeding is inevitable and father-daughter and mother-son matings have been recorded. The balance of the sexes may be distorted by an excess of males or females surviving to maturity, thus increasing the impact of inbreeding. A loss of variability and genetic deterioration follow, with lowered cub production and survival, which may not be apparent until they have reached a level that threatens the population. 

Impact of Catastrophes

Small isolated populations are especially vulnerable to catastrophic events: natural disasters, such as forest fires, floods, hurricanes, and epidemics; and human-induced events, such as deforestation and conversion of habitat. Extensive fires in the fore sts of northeastern China in 1987 may have killed Siberian tigers, and reduced prey numbers. Monsoon floods and hurricanes regularly kill some tigers in the Indian subcontinent.

In Africa, an outbreak of canine distemper, which killed dozens of lions in Tanzania's Serengeti National Park in 1994/5, is unlikely to damage the total population of 3,000. But a similar epidemic in India or elsewhere in Asia could wipe out a small tiger population, especially if inbreeding has reduced genetic variability and, therefore, resistance to the spread of disease.