Indochinese tiger

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Indochinese tiger
Vietnamese: Hổ Đông Dương
Thai: เสือโคร่งอินโดจีน
Panthera tigris corbetti 01.jpg
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Felidae
Genus: Panthera
Species: P. tigris
Subspecies: P. tigris corbetti
Trinomial name
Panthera tigris corbetti
Mazák, 1968
Indochinese Tiger Habitat.png
Distribution of the Indochinese Tiger (in red)

The Indochinese tiger (Panthera tigris corbetti) is a tiger subspecies dispersed throughout the Indochina region of Southeastern Asia. In 2007, its population comprised less than 2,500 individuals with no subpopulations greater than 250 individuals, so the IUCN Red List of Threatened Species categorized the Indochinese tiger as Endangered. Estimates range from 202 to 352 total individuals in the wild, so the Indochinese tiger approaches the threshold for Critically Endangered.[1] There is restricted access to border areas where this subspecies lives, so there is very little accurate information regarding its population status.[2]

The tigers in peninsular Malaysia, formerly classified as Indochinese, have recently been reclassified as a separate subspecies, the Malayan tiger Panthera tigris jacksoni.[3][4]

Background[edit]

The Indochinese tiger is also referred to as "Corbett's tiger." This name is a reference to the British Colonel and hunter turned conservationist Jim Corbett. In the early 1900s Corbett, an avid hunter, was often called to regions of India to deal with "problem cats." While his work was originally dedicated to eradicating troublesome panthers and tigers from various villages throughout India, he eventually began to raise support and awareness for environmental and animal conservation. The Indochinese tiger was named in his honor.[5]

Characteristics[edit]

The Indochinese tiger is a solitary animal. Their elusive behavior has made them difficult to observe and study in the wild, so there is little known about them. When compared to other tiger subspecies, the Indochinese tiger is generally smaller in stature.[6] Another distinction that sets them apart is their narrower stripes and the deeper, more vibrant orange of their coat that is sometimes referred to as golden.[6][7] The males range in size from 2.2 to 2.4 m (7.2 to 7.9 ft), weighing about 150 and 200 kg (330 and 440 lb). The females range in size from 2 to 2.2 m (6.6 to 7.2 ft), weighing between 100 and 130 kg (220 and 290 lb). Their lifespan can range from 15 to 26 years of age depending on factors like living conditions and whether they are wild or in captivity. Due to their dwindling numbers, Indochinese tigers are known to inbreed, mating with available immediate family members. Inbreeding within this subspecies has led to weakened genes, lowered sperm count, infertility and in some cases defects such as cleft palates, squints, crossed-eyes, and swayback.[6][8]

Distribution and habitat[edit]

Historically, the Indochinese tiger has made its home in the Indochina region of Southeastern Asia, specifically within the countries of China, Lao PDR, Thailand, Vietnam, Myanmar, and Cambodia. More than half of the total population is found in the Western Forest Complex in Thailand, especially in the area of the Huai Kha Khaeng Wildlife Sanctuary.[1] Its habitat consists of tropical and subtropical moist broadleaf forests.[2] Forests provide this tiger subspecies with camouflage, and its preference for mountainous regions provides them with hunting grounds that fit their lifestyle and dietary needs.[6] The Indochinese tiger populations within these traditional habitats have been dwindling. Within Cambodia, China, and Vietnam there exists no evidence of breeding tiger populations.[9] In fact, China's last known Indochinese tiger was killed and eaten by a poacher in 2007.[2]

Tiger Population Estimates
Country Minimum Maximum Reliability
Cambodia 11 50 Fair
Lao PDR 30 30 Fair
Myanmar 100 150 Fair
Thailand 250 750 Fair
Vietnam 30 150 Poor
Total 421 1,100

The above numbers were collected by IUCN from national tiger population estimates for the purpose of deriving a global tiger population estimate. The numbers vary in reliability and quality among the data collection methods from a recent scientific census (good) to partial site studies (fair) to educated guesswork (poor).[1]

Ecology and behaviour[edit]

Indochinese tigers prey mainly on medium- and large-sized wild ungulates. Sambar deer, wild pigs, serow, and large bovids such as banteng and juvenile gaur comprise the majority of Indochinese tiger’s diet. However, in most of Southeast Asia large animal populations have been seriously depleted because of illegal hunting, resulting in the so-called “empty forest syndrome” – i.e. a forest that looks intact, but where most wildlife has been eliminated.[10][11] Some species, such as the kouprey and Schomburgk's Deer, are extinct, and Eld's Deer, hog deer and wild water buffalo are present only in a few relict populations. In such habitats tigers are forced to subsist on smaller prey, such as muntjac deer, porcupines, macaques and hog badgers. Small prey by itself is barely sufficient to meet the energy requirements of a large carnivore such as the tiger, and is insufficient for tiger reproduction. This factor, in combination with direct tiger poaching for traditional Chinese medicine, is the main contributor in the collapse of the Indochinese tiger throughout its range.[12]

Reproduction[edit]

Indochinese tigers mate throughout the year, but most frequently during November through early April. After a gestation period of 3.5 months, roughly 103 days, a female Indochinese tiger is capable of giving birth to seven cubs. However, on average a female will only give birth to three. Indochinese tiger cubs are born with their eyes and ears closed until they begin to open and function just a few days after birth. During the first year of life there is a 35% mortality rate, and 73% of those occurrences of infant mortality are the entire litter. Infant mortality in Indochinese tigers is often the result of fire, flood, and infanticide. As early as 18 months for some but as late as 28 months for others, Indochinese tiger cubs will break away from their mothers and begin hunting and living on their own. Females of the subspecies reach sexual maturity at 3.5 years of age while it takes males up to 5 years to reach sexual maturity.[6][8]

Threats[edit]

The primary threat to Indochinese tigers is mankind. Humans hunt Indochinese tigers to make use of their body parts for adornments and various Eastern traditional medicines. Indochinese tigers are also facing habitat loss. Humans are encroaching upon their natural habitats, developing, fragmenting, and destroying the land. In Taiwan, a pair of tiger eyes, which are believed to fight epilepsy and malaria, can sell for as much as $170. In Seoul, powdered tiger humerus bone, which is believed to treat ulcers, rheumatism, and typhoid, sells for $1,450 per pound. In China, the trade and use of tiger parts was banned in 1993, but that has not stopped poachers who can earn as much as $50,000 from the sale of a single tiger’s parts on the black market. With a growing affluence in countries where tiger parts are so greatly valued, demand is high.[13] Located in the Kachin State of Myanmar, the Hukaung Valley is the world's largest tiger reserve and is home to Myanmar's remaining Indochinese tiger population. Since 2006, the Yuzana Corporation's wealthy owner Htay Myint alongside local authorities has expropriated more than 200,000 acres of land from more than 600 households in the valley. Much of the trees have been cut down and the land has been transformed into plantations. Some of the land taken by the Yazana Corporation had been deemed tiger transit corridors. These are areas of land that were supposed to be left untouched by development in order to allow the region’s Indochinese tigers to travel between protected pockets of reservation land.[14] The Burmese Civil War has been an ongoing conflict within the country of Myanmar since 1948. Because of renewed rebel uprising in 2011 from the Kachin Independence Army who occupy a portion of the Hukaung Valley, foreign poaching threats have been unable to safely enter the region. Not only are foreigners restricted from entering the region but reservation staff as well. Among indigenous people, particularly the impoverished, the Indochinese tiger is a valuable resource. Because of the danger of civil conflict, the reservation staff have had a difficult time protecting the tigers from the native population. In early January 2013, rumors of a ceasefire between the government and rebel forces began to circulate. The country’s leaders believed that a resolution could have been reached as early as October 2013. Having been unable to establish themselves as a protective force in the region, there is concern that foreign poachers will begin moving back into the soon to be peaceful region before the reservation staff.[15]

Consequences[edit]

Throughout out all ecosystems they inhabit, tigers are a top predator. When a top predator is in decline or even totally removed from an ecosystem, there are serious consequences that trickle down through the food web and disrupt the proper functioning of an ecosystem. They control population growth and decline and increase species diversity.[16] William J. Ripple, a professor of forestry at Oregon State University made it clear that:

The data from Canada, Alaska, the Yukon, Northern Europe and Asia are all showing similar results. There's consistent evidence that large predators help keep populations of large herbivores in check, with positive effects on ecosystem health.[16]

In the event of the extinction of the Indochinese tiger subspecies it is possible that prey populations would explode. As herbivorous populations increase, the diversity and productivity of native plant communities would decline substantially.[16] Competition among species would also increase, causing some to dominate over others due to sheer population size. Species diversity would decline, and the ecosystem would be thrown completely off balance. Historically, other top predators have been removed from an ecosystem and similar effects were seen such as in the case of the Yellowstone National Park wolves.[17]

Despite being illegal, the trade of tiger parts on the black market provides many poachers with substantial income. While it is an illegal and frowned upon profession, many poachers do what they do because they are impoverished and have limited options for obtaining a substantial and steady income otherwise.

In captivity[edit]

The population in captivity of pure Indochinese tigers is low as the animals once included in this subspecies' breeding programs were found to be of the recently discovered Malayan tiger, Panthera tigris jacksoni. According to Nat Geo News Watch contributor Jordan Schaul:

Prior to the designation of the Malay subspecies there were approximately 60 Indochinese tigers in Asian and North American zoos. Today there are less than a handful, including some in San Diego and at the Birmingham zoo.[18]

Schaul goes on to say, "...zoos are committed to conserving the genetic integrity of the subspecies that do exist in the wild."[18]

References[edit]

  1. ^ a b c d Lynam, A. J. and Nowell, K. (2011). "Panthera tigris ssp. corbetti". IUCN Red List of Threatened Species. Version 2013.1. International Union for Conservation of Nature. 
  2. ^ a b c WWF. "Indochinese tiger". Retrieved 15 October 2013. 
  3. ^ Luo, S.-J., Kim, J.-H., Johnson, W. E., van der Walt, J., Martenson, J., Yuhki, N., Miquelle, D. G., Uphyrkina, O., Goodrich, J. M., Quigley, H. B., Tilson, R., Brady, G., Martelli, P., Subramaniam, V., McDougal, C., Hean, S., Huang, S.-Q., Pan, W., Karanth, U. K., Sunquist, M., Smith, J. L. D., O'Brien, S. J. (2004). "Phylogeography and genetic ancestry of tigers (Panthera tigris)". PLoS Biology 2 (12): e442. doi:10.1371/journal.pbio.0020442. PMC 534810. PMID 15583716. 
  4. ^ Kawanishi, K., Lynam, T. (2008). "Panthera tigris subsp. jacksoni". IUCN Red List of Threatened Species. Version 2013.1. International Union for Conservation of Nature. 
  5. ^ "Tiger Subspecies: Indochinese Tiger". Panthera. Retrieved 16 October 2013. 
  6. ^ a b c d e "The Indochinese Tiger". www.tigers.org.za. Retrieved 16 October 2013. 
  7. ^ BioExpedition Publishing (15 January 2013). "Indochinese Tiger Information". BioExpedition.com. Retrieved 16 October 2013. 
  8. ^ a b "Indo-Chinese Tiger". Indian Tiger Welfare Society. Retrieved 16 October 2013. 
  9. ^ "Bringing the Tiger Back from the Brink—The Six Percent Solution". PLOS Biology. 2010-09-14. Retrieved 2013-11-15. 
  10. ^ "Asia’s biodiversity vanishing into the marketplace". 
  11. ^ "Wildlife trade creating "empty forest syndrome" across the globe". 
  12. ^ Karanth, K.U., Stith, B.M. 1999: Prey depletion as a critical determinant of tiger population viability. In: Seidensticker/ Christie/ Jackson: Riding The Tiger: Tiger Conservation in human-dominated landscapes. Cambridge University Press, 1999 ISBN 0-521-64835-1
  13. ^ "The Trade in Tiger Parts". Tigers in Crisis. Retrieved 15 October 2013. 
  14. ^ Martov, Seamus. "World's Largest Tiger Reserve 'Bereft of Cats'". The Irrawaddy. Retrieved 16 October 2013. 
  15. ^ Rook, Daniel. "Civil war endangers Myanmar's ailing tigers". AFP. Retrieved 16 October 2013. 
  16. ^ a b c Ripple, William. "Study: Loss of predators affects ecosystems". United Press International, Inc. Retrieved 15 November 2013. 
  17. ^ "The Wolves or Yellowstone". Brooks/Cole. 
  18. ^ a b Jordan Schaul (November 19, 2010). "Managing Tiger Species Survival in American Zoos". Nat Geo News Watch. Retrieved 19 November 2013. 

External links[edit]