Sumatran tiger

The Sumatran tiger is a population of Panthera tigris sondaica on the Indonesian island of Sumatra. It is the only surviving tiger population in the Sunda Islands, as the other Bali and Javan tigers went extinct during the 20th century.

Sequences from complete mitochondrial genes of 34 tigers support the hypothesis that Sumatran tigers are diagnostically distinct from existing mainland subspecies. In 2017, the Cat Classification Task Force of the Cat Specialist Group revised felid taxonomy and recognizes the living and extinct tiger populations in Indonesia as P. t. sondaica.

Panthera tigris sumatrae was proposed by Reginald Innes Pocock in 1929, who described a skin and a skull of a tiger zoological specimen from Sumatra.

The skull and pelage pattern of tiger specimens from Java and Sumatra do not differ significantly.

P. t. sondaica is therefore considered the valid name for the living and extinct tiger populations in Indonesia.

Characteristics

thumb|Resting Sumatran tiger in Lok Kawi Wildlife Park

The Sumatran tiger was described based on two zoological specimens that differed in skull size and striping pattern from Bengal and Javan tiger specimens. It is darker in fur colour and has broader stripes than the Javan tiger. The frequency of stripes is higher than in other subspecies.

Males have a prominent ruff, which is especially marked in the Sumatran tiger.

The Sumatran tiger is one of the smallest tigers. Males measure between the pegs in head-to-body length, with the greatest skull length of and weigh . Females weigh and measure in length between the pegs with a greatest length of skull of .

Distribution and habitat

The Sumatran tiger persists in small and fragmented populations across Sumatra, from sea level in the coastal lowland forest of Bukit Barisan Selatan National Park on the southeastern tip of Lampung Province to in mountain forests of Gunung Leuser National Park in Aceh Province. It is present in 27 habitat patches larger than , which cover . About a third of these patches are inside protected areas.

Sumatran tigers prefer lowland and hill forests, where up to three tigers live in an area of ; they use non-forest habitats and human-dominated landscapes at the fringes of protected areas to a lesser degree.

In 1978, the Sumatran tiger population was estimated at 1,000 individuals, based on responses to a questionnaire survey. In 1985, a total of 26 protected areas across Sumatra containing about 800 tigers were identified. In 1992, an estimated 400–500 tigers lived in five Sumatran national parks and two protected areas. At that time, the largest population unit comprised 110–180 individuals in Gunung Leuser National Park.

As of 2011, the tiger population in Kerinci Seblat National Park in central Sumatra comprised 165–190 individuals, which is more than anywhere else on the island. The park has the highest tiger occupancy rate of Sumatra's protected areas, with 83% of the park showing signs of tigers.

Sumatra's total tiger population was estimated at 618 ± 290 individuals in 2017.

Camera trapping surveys conducted in southern Riau revealed an extremely low abundance of potential prey and a low tiger density in peat swamp forest areas. Repeated sampling in the newly established Tesso Nilo National Park documented a trend of increasing tiger density from 0.90 individuals per in 2005 to 1.70 individuals per in 2008.

In the Bukit Barisan Selatan National Park, nine prey species larger than of body weight were identified including great argus, pig-tailed macaque, Malayan porcupine, Malayan tapir, banded pig, greater and lesser mouse-deer, Indian muntjac, and Sambar deer.

Conflicts with humans are another major threat to the Sumatran tiger. Poachers target tigers with wire snares, and they are also inadvertently caught in traps set by deer hunters and farmers attempting to control crop raids from wild boar.

Tigers need large contiguous forest blocks to thrive.

Sumatra's largest tiger population in Kerinci Seblat National Park is threatened by a high rate of deforestation in its outer regions. Drivers are an unsustainable demand for natural resources created by a human population with the highest rate of growth in Indonesia, and a government initiative to increase tree-crop plantations and high-intensity commercial logging, which ultimately leads to forest fires. The majority of the tigers found in the park were relocated to its center where conservation efforts are focused, but issues in the lowland hill forests of the outskirts remain. While being a highly suitable tiger habitat, these areas are also heavily targeted by logging efforts, which substantially contributes to declines in local tiger numbers.

The expansion of plantations is increasing greenhouse gas emissions, playing a part in anthropogenic climate change, thus further adding to environmental pressures on endangered species. Climate-based movement of tigers northwards may lead to increased conflict with people. From 1987 to 1997, Sumatran tigers reportedly killed 146 people and at least 870 livestock. In West Sumatra, Riau, and Aceh, a total of 128 incidents were reported; 265 tigers were killed and 97 captured in response, and 35 more tigers were killed from 1998 to 2002. From 2007 to 2010, the tigers caused the death of 9 humans and 25 further tigers were killed. In 2006, wildlife markets were surveyed in 28 cities and nine seaports in seven Sumatran provinces; 33 of 326 retail outlets offered tiger parts like skins, canines, bones, and whiskers. Tiger bones fetched the highest average price of US$116 per kg, followed by canines. There is evidence that tiger parts are smuggled out of Indonesia. In July 2005, over of tiger bones and 24 skulls were confiscated in Taiwan in a shipment from Jakarta.

In 2013–2014, Kerinci Seblat National Park experienced an upsurge in poaching, with the highest annual number of snare traps being removed for a patrol effort similar to previous years. Evidence is scarce and misunderstood on whether the strategies implemented to diminish poaching are succeeding despite the investment of millions of dollars annually into conservation strategies.

In provincially-managed forests in Aceh province, Sumatran tigers are threatened by poaching due to insufficient or nonexistent ranger patrols. Between January 2020 and June 2025, 127 tigers were confiscated in 77 seizures in Indonesia.

Conservation

Panthera tigris is listed on CITES Appendix I. Hunting is prohibited in Indonesia. By August 1999, the teams of the STP had evaluated 52 sites of potential tiger habitat in Lampung Province, of which only 15 were intact enough to contain tigers. In the framework of the STP, a community-based conservation programme was initiated to document the tiger-human dimension in the park to enable conservation authorities to resolve tiger-human conflicts based on a comprehensive database rather than anecdotes and opinions.

In 2007, the Indonesian Forestry Ministry and Safari Park established cooperation with the Australia Zoo for the conservation of Sumatran tigers and other endangered species. The program includes conserving Sumatran tigers and other endangered species in the wild, efforts to reduce conflicts between tigers and humans, and rehabilitating Sumatran tigers and reintroducing them to their natural habitat.

Indonesia's struggle with conservation has caused an upsurge in political momentum to protect and conserve wildlife and biodiversity. In 2009, Indonesia's president committed to substantially reduce deforestation, and policies across the nation requiring spatial plans that would be environmentally sustainable at national, provincial, and district levels.

Between 2005 and 2015, about US$210 million have been invested into tiger law-enforcement activities that support forest ranger patrols, as well as the implementations of front-line law-enforcement activities by the Global Tiger Recovery Plan, which aims to double the number of wild tigers by 2020.

In November 2016, Batu Nanggar Sanctuary was opened in North Padang Lawas Regency, North Sumatra

for conservation of Sumatran wildlife.

An interview survey among 600 consumers revealed that most were willing to pay consistently more for a "tiger-friendly" produced good if this product would be conducive to Sumatran tiger conservation.

In captivity

As of 2013, about 375 captive Sumatran tigers were listed in the global studbook and management plan, with 50 of them housed in 14 zoos in Australia and New Zealand. All of them were offspring of 15 founders. Fourteen cubs showed congenital vestibular system dysfunctions such as ataxia, strabismus, nystagmus, head tilting and falling that resolved when they were two years old. The cause for this disorder is most likely their close genetic relation and inbreeding.

References

External links

and
() at the National Zoological Park (United States)