CatSG

Tiger

Panthera tigris 

IUCN Red List: Endangered

Weight: 75-325 kg
Body length: 150-230 cm
Tail length: 90-110 cm
Longevity: 12-15 years
Litter size: 1-5 cubs

Description

The tiger (Panthera tigris) evolved, along with other modern felids in the Panthera lineage, from an ancestral cat species around 10.8 million years ago. Several million years later, the tiger branched off along with the other "great roaring cats" of the modern Panthera genus. The oldest known tiger fossils, approximately 2 million years old, were found in China and on Java, Indonesia.

The tiger once ranged throughout southern and eastern Asia. Approximately 73,000 years ago, the Toba volcanic eruption on Sumatra may have resulted in a major range reduction, population bottleneck, and resultant decreased genetic variation in the survivors.The most recent common ancestor for tiger matrilineal mitochondrial DNA is estimated to have originated 72,000-108,000 years ago.

The modern tiger was considered to consist of six extant and three extinct subspecies. The six living tiger subspecies are organised based on distinctive molecular markers:

The three recognised extinct tiger subspecies based on morphological differences are:

  • Bali tiger P. t. balica, once living on the island of Bali
  • Javan tiger P.t. sondaica once living on the island of Java
  • Caspian tiger P.t. virgata, once found in western Asia, including: Afghanistan, Armenia, Azerbaijan, Georgia, Kazakhstan, Kyrgyzstan, Iraq, Iran, Tajikistan, Turkey, Turkmenistan, and Uzbekistan. 

However, based on recent studies, only two tiger subspecies are proposed:

  • Panthera tigris tigris (including virgata, altaica, amoyensis corbetti and jacksoni) in mainland Asia including India, Pakistan, Nepal, Bhutan, Sikkim, China, Russia, Indochina and the Malay Peninsual and 
  • Panthera tigris sondaica (including balica and sumatrae) on Sumatra and formerly Java and Bali

In addition Caspian/Amur tigers formerly occurred in the Altai region of Russia, western China, parts of Mongolia, and on the Korean peninsula.

Subspecies

Weight (kg)

Total length (m)

Skull length (mm)

Male

Female

Male

Female

Male

Female

Altaica

180-306

100-167

2.7-3.3

2.4-2.75

241-383

279-318

Amoyensis

130-175

100-115

2.3-2.65

2.2-2.4

318-343

273-301

Balica

90-100

65-80

2.2-2.3

1.9-2.1

295-298

263-269

Corbetti

150-195

100-130

2.55-2.85

2.3-2.55

319-365

279-302

Sondaica

100-141

75-115

2.48

306-349

270-292

Sumatrae

100-140

75-110

2.2-2.55

2.15-2.3

295-335

263-294

Tigris

180-258

100-160

2.7-3.1

2.4-2.65

329-378

275-311

Virgata

170-240

85-135

2.7-2.95

2.4-2.6

316-369

268-305

The tiger is the largest living cat species, although there is considerable variation among subspecies and large lions can be larger than smaller tigers. The tiger is the only cat species with stripes. It has a reddish-orange to yellow-ochre coat with black stripes and a white belly. The stripe patterns are unique to individual tigers. The stripes vary in number, as well as width and propensity to split and run to spots. The dark lines above the eyes tend to be symmetrical, but the marks on the sides of the face can be different. Males have a prominent ruff which is especially marked in the Sumatran tiger. In India, tigers with a white coat, ashy grey or brown stripes, and blue eyes, have been described from the forests of Assam, Orissa, Madhya Pradesh and Bihar. The last record of a white tiger shot in Bihar is from 1958. Since then, there were no recent reports of white tigers from any part of India.

The tiger evolved to effectively hunt and kill large ungulates. It has a relatively large skull with extraordinary canines and a powerful overall build.

Other names

Language/Country

Name

Bangladesh (Bengali; Hindi)

bagh

Chinese

lao hu

French

tigre

German

Tiger

India (Bengali; Hindi)

bagh

Indonesia

rimau, harimau

Iran (Farsi)

babr

Laos

sua khong, sua lay

Malaysia

rimau, harimau

Russia

tiger

Spanish

tigre

Thailand

seua

Tibetan

rag

Udege, Amur river region (Russian)

amba darla

Bengal tiger, India.
Amur tiger.
Amur tiger.
White tiger in Madrid Zoo.

Status and Distribution

The tiger is listed as Endangered by the IUCN Red List. In 2009, the in situ tiger population was estimated to be around 3,200 individuals with likely fewer than 2,500 mature animals. This represents a significant decline from an estimated 100,000 living at the beginning of the 20th century. Many tiger populations are very small and isolated. The tiger populations from 42 protected sites with evidence of breeding were estimated to number only 2,154 individuals in 2010. Population estimates of tigers outside protected areas are less known. Currently, the total population size of tigers is estimated at 3,159 animals based on field data from 2009-2014 and at 4,240 individuals according to official government estimates published in 2011 in the Global Tiger Recovery Program.

Tigers survive only in scattered populations in 13 range countries: Bangladesh, Bhutan, Cambodia, China, India, on the island of Sumatra in the Republic of Indonesia, Lao PDR, peninsular Malaysia, Myanmar, Nepal, the Russian Far East, Thailand, and Vietnam. Evidence of breeding populations is limited to Bangladesh, Bhutan, India, Indonesia, Malaysia, Nepal, Russia and Thailand. Between 2009 and 2014, there was also evidence of breeding in China and Myanmar. The tiger may still persist in North Korea, although there has been no recent confirmed evidence.

Tiger population estimates

Country/Region

Estimated population size

Bangladesh

300-500 (offical government estiamte)

Bhutan (Royal Manas NP and Jigme Singye NP)

43-61

China

>7

India

1,520-1,909 

Indonesia

371-1,273

Lao PDR

2

Malaysia

250-340

Nepal

163-235

Russia

330-390 (official government estimate)

Thailand

189-252

Viet Nam

<5

Tiger density varies. In India's Kaziranga and Corbett National Parks with abundant prey, densities of 17-19 animals/100 km² and in the Sikhote Alin Mountains in Russia with low prey availability, densities of 0.13-0.45/100 km² have been estimated.

The geographic distribution of the tiger once extended across Asia from eastern Turkey and the southern parts of the Caspian Sea to the Sea of Okhotska (eastern coast of Russia). Today, an estimated 7% or less of its original historical range remains. The tiger has disappeared from modern-day Afghanistan, Georgia, the islands of Bali and Java in the Republic of Indonesia, Iran, Iraq, Kazakhstan, Kyrgyzstan, Pakistan, Singapore, South Korea, Tajikistan, Turkey, Turkmenistan, and Uzbekistan. 

Distribution area of the tiger (red = extant, dark yellow = possibly extinct) (IUCN Red List of Threatened Species 2015).

Habitat

The tiger is found in a variety of habitats from the tropical evergreen and deciduous forests of southern Asia to the coniferous, scrub oak, and birch woodlands of the Russian Far East. It also thrives in the mangrove swamps of the Sunderbans, the dry thorn forests of northwestern India, and the tall grass jungles at the foot of the Himalayas. The tiger can be found from the lowland swamp forests of Sumatra to the dry high altitude areas of Bhutan, where it has been recorded up to 4,000m above sea level. The main habitat requirements of a tiger are dense vegetation cover, access to water and sufficient large ungulate prey. 

Bengal tiger in Kanha, India.
Habitat of the Bengal tiger, Pench, India.

Ecology and Behaviour

The tiger is a solitary animal. Females require and maintain individual territories. Males disperse sometimes over long distances and their territories often overlap. The size of individual home ranges can be large and females must aggressively defend the resources within their home range while males have to search extensively and compete for available mates. The sizes of home ranges vary in accordance with prey densities. While females need ranges suitable for raising cubs, males seek access to females and have larger ranges. In areas rich in prey throughout the year (e.g., Nepal’s Chitwan National Park), studies have found female home ranges averaging 10-39 km² in size and male home ranges around 30-105 km². In the Russian Far East where prey is unevenly distributed and moves seasonally, home ranges can reach 100-400 km² for females and averaging 1,379 km² for males. In the Sundarbans of Bangladesh female home range size have been found ranging from 12.3 to 14.2 km².

The tiger is an obligate terrestrial carnivore. It ambushes its prey but also actively searches for prey species. It often drags its kill to nearby cover to feed on. It hides the parts which have not yet been consumed and generally returns to feed on it.

The reproduction season depends on the region. Studies have found that reproduction can take place year-round: from December to February in Manchurei, from November to April in India, and birth peak from May to July in Nepal. Estrus lasts for seven days and the estrus cycle for 15 to 20 days in Rajasthan (India). Others reported estrus cycles of 46 to 52 days and 34 to 61 days. If a litter is lost, estrus occurs within a few weeks (mean 17 days, range 10-39). Gestation lasts for approximately 103 days. The interbirth interval is on average 20 to 24 month, but can last up to 36 months. However, if the litter is lost in the first two weeks, the interval can be 8 months. Age at independence is 18 to 28 months. In Chitwan, first-year cub mortality was around 34% of which 73% was whole litter loss due to causes including fire, floods and infanticide. Mortality in the second year of life was 17% of which only 29% was whole litter loss. Infanticide was overall the most common cause of cub death. Studies have suggested that populations decline when the mortality of breeding females exceeds 15%.

Data collected over nearly 20 years by the long-term tiger population monitoring project at Nepal’s Chitwan National Park found the average reproductive life span of tigers to be 6.1 years for females and 2.8 years for males. Age at first reproduction is at 3.4 years for females and at 4.8 years (3.4-6.8 years) for males. Age at last reproduction was recorded at 14 years. The mean number of offspring surviving to dispersal was estimated at 4.54 for females and the average number of offspring eventually incorporated into the breeding population was just 2.0. For males an average of 5.83 of their offspring survived to dispersal and 1.99 were incorporated into the breeding population.

Bengal tiger in a river in Pench, India.
Amur tigers.
Bengal tigers in Kanah, India.
Tiger claw marks on a tree, India.

Prey

The main prey species of the tiger are large ungulates such as chital (Axis axis), gaur (Bos gaurus), sambar (Cervus unicolor), wild pig (Sus scrofa) and muntjac (Muntiacus muntjak). The tiger also preys on red deer, roe deer, peafowl and musk deer. The tiger sometimes kills livestock and small prey such as hares. The diet of the tiger is biogeographically diverse. In India, its diet consists of chital, sambar, nilgai, chinkara, wild pig and common langur make part of its diet. In Cambodia, the major prey species are barking deer, wild boar, sambar, gaur and banteng. Tigers need around 50-60 large prey animals per year.

Main Threats

One of the main threats to the tiger today is illegal hunting. They are killed to supply the illegal trade in tiger skin, bones, meat and other body parts, particularly for use in traditional East Asian medicines. This illegal trade is contributing to the rapid disappearance of tigers from much of its current range. 

Tigers were once widely hunted for sport and trophy hunting. Legal and illegal hunting of tigers also occurred widely throughout the 19th and much of the 20th Century to prevent conflict or in retaliation for conflict between tigers, people and property. Poaching pressure on tigers is still high. Traffic reported seizures and confiscations in 2007-2009 averaging the equivalent of approximately 150 tigers per year. All countries have banned the use or creation of tiger bone. However, illegal production exists in Asian countries as China, Malaysia and Viet Nam. In China there are so called tiger farms in place with intensive breeding of captive animals and which produce illegally tiger bone wine.

Another major threat is habitat loss and degradation due to infrastructure development, human settlements, logging, and land clearance for plantations such as oil palm or rubber plantations. Such activities also increase human access to forest areas for poaching. The tiger has lost over 93% of its historical range. Increasing human populations and settlements, agricultural expansion, and other economic development have led to the loss and fragmentation of tiger habitat.  Many tiger populations are isolated and a growing number are so small that genetic inbreeding is a serious concern.

The main prey species of the tiger are also under high pressure from hunting, habitat loss and degradation, and competition from people and domestic livestock. The type and density of prey influence many characteristics of tiger population biology, including reproduction and survival. Loss of adequate prey species can be an important predictor of tiger population health.

Direct and indirect conflict between tigers and humans and their property has historically been a major source of tiger mortality and remains an important threat today. Tigers may kill livestock and have attacked or killed people everywhere tigers and people coexist. This conflict often has led affected individuals and communities to retaliate by using lethal control to remove tigers using guns, poison, traps, or other methods. Some tigers are captured and moved or placed in captive breeding facilities by authorities following attacks on people or livestock. Tiger-human conflict contributed significantly to the eradication of tigers from western Asia, the island of Java, Singapore, and large swaths of China and the Russian Far East.      

All of these threats were likely responsible for the extinction of the Bali, Javan, and Caspian tigers. Habitat was converted and fragmented, critical ungulate prey were lost through disease and over-hunting by humans, and hunting of tigers for sport and official eradication programs likely played a role in their historical decline. 

Conservation Effort and Protection Status

The tiger is included in Appendix I of CITES. The tiger is protected over most of its range. Hunting is prohibited in Bangladesh, Bhutan, Cambodia, China, India, Indonesia, Lao PDR, Malaysia, Myanmar, Nepal, Russia, Thailand and Vietnam. There is no information for North Korea available.

Various initiatives have been launched to conserve the species and many tiger conservation efforts have been undertaken at local, regional, national, and international scales. Among the most notable early conservation efforts, "Project Tiger" was launched in India in 1973 as a nationwide effort to counter the disappearance of tigers in that country. Project Tiger contributed to the establishment of dedicated tiger reserves throughout India. Over the past several decades many other countries have launched their own tiger conservation efforts, with varying success. 

Recognizing the crisis facing tigers and tiger habitat throughout Asia, political leaders of the 13 tiger range states and representatives of conservation NGOs and donor organizations signed the St. Petersburg Declaration (a Global Tiger Recovery Program) in 2010, with the goal to stabilize and eventually double the population of wild tigers by 2022 to at least 6,000 individuals. The following goals and actions are intended to help reach that goal:

  • Preserve, manage, enhance and protect tiger habitats;
  • Stop poaching, smuggling and illegal trade of tigers, their parts and derivatives;
  • Cooperate in transboundary landscape management;
  • Work together to combat illegal trade;
  • Include indigenous and local communities in planning and implementation;
  • Increase the effectiveness of tiger and habitat management; and
  • Restore tigers to their former range.

Recognition among policy makers that economic development, conflict over land use, human-wildlife conflict, and domestic and international trade in wildlife are major threats to the survival of tigers will be necessary for long-term conservation to succeed.

There is widespread agreement that conservation of large and suitable habitats for tigers is needed, including the linking of core tiger populations. Landscape analyses have estimated that tiger reserves could support more than double current tiger numbers but that national and international commitment and cooperation for conservation will be crucial for success. “Source” populations and core protected tiger areas are unevenly distributed and may represent only 6% of current tiger range. Protecting and monitoring these remaining breeding populations, establishing and protecting corridors and transboundary conservation areas to support gene flow among disjunctive populations, are conservation priorities.

Reduction in human-caused mortality of tigers and tiger prey is also crucial for long-term survival of tigers in the wild. This must include stopping the illegal killing and trade of tigers and their parts, conservation of tiger prey, and effective management of conflict between tigers and humans through improved livestock management, the inclusion of local people into the monitoring and management of tiger habitat, and other approaches.

Local, regional, national, and international support is needed to address other direct and indirect threats, including: economic drivers of habitat loss and illegal activity, and production and movement of pollution and other environmental stressors. A successful management towards recovery of tier populations requires mitigation of disease threats, participation and cooperation of diverse stakeholders, strengthening of conservation laws, institutions, and financial resources, reduction of graft, and changes in knowledge, attitudes, and behaviour of people and institutions that ultimately impact tigers and their habitat. A wide diversity of conservation and restoration activities are ongoing throughout the tigers range to address these challenges.