The Sumatran tiger, an apex predator, is one of the world’s most threatened big cat subspecies. It is the only tiger subspecies found on the Indonesian island of Sumatra, roaming dense rainforests. Its conservation status is critically endangered, signifying an extremely high risk of extinction. This highlights the severe pressures this species faces in its natural habitat.
Vanishing Forests and Homes
The primary threat to Sumatran tigers is the rapid destruction and fragmentation of their forest habitat. Deforestation on Sumatra is driven largely by the expansion of palm oil plantations, pulp and paper industries, and agricultural development. This widespread clearing reduces the overall area where tigers can live and hunt, and isolates remaining tiger populations.
The conversion of lowland forests is devastating, as these areas historically harbored the highest density and diversity of animal species, including Sumatran tigers. As their habitat shrinks, tigers are confined to smaller, disconnected forest patches, making it difficult for them to find mates and maintain genetic diversity. This forces tigers into increasingly limited ranges, often pushing them to higher altitudes where the habitat can sustain only a fraction of the population that could thrive in lower forest territories.
The Illegal Wildlife Trade
Poaching constitutes another direct cause of Sumatran tiger mortality. These tigers are highly sought after in the illegal wildlife trade for their body parts, which are valued in black markets across Asia, particularly in China. Bones, skin, teeth, claws, and whiskers are used in traditional medicines, as decorative items like rugs or amulets, or as status symbols.
The illegal trade ranks as the third most profitable black market trade globally after drugs and weapons. Poachers often employ snares, which can severely injure or kill tigers, even if initially set for other wild animals like pigs or deer. Despite international bans and national laws, enforcement remains a challenge, allowing this trade to persist and deplete tiger numbers.
Clashes with Human Settlements
As human populations expand and agricultural activities encroach further into tiger habitats, conflicts between tigers and people become more frequent. Tigers, facing shrinking forest areas and dwindling natural prey, are often forced to venture closer to human settlements in search of food. This leads to instances where tigers may prey on livestock, a vital source of income for local communities.
Such incidents can provoke retaliatory killings by farmers and villagers seeking to protect their livelihoods or ensure their safety. Between 2000 and 2016, approximately 130 tigers were killed due to conflict with local inhabitants. While tiger attacks on humans are less common, they do occur, with one study reporting human deaths and injuries between 1978 and 1997.
The Perils of Small Numbers
With a critically low population, estimated to be fewer than 600 mature individuals, Sumatran tigers face genetic vulnerabilities. A small population size increases the likelihood of inbreeding, where related individuals mate due to limited options. This reduces the overall genetic diversity within the population.
Lower genetic diversity diminishes the species’ ability to adapt to environmental changes, such as new diseases or shifts in climate, making their long-term survival precarious. The ongoing fragmentation of their habitat continues to pose a significant risk of genetic isolation and subsequent inbreeding depression if populations remain small and disconnected.