Banteng

Banteng
Java banteng (bull)
Conservation status

Endangered (IUCN 3.1)[1]
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Subfamily: Bovinae
Genus: Bos
Species: B. javanicus
Binomial name
Bos javanicus
d'Alton, 1823
Subspecies

B. j. birmanicus
B. j. javanicus
B. j. lowi

The Banteng (Bos javanicus), also known as Tembadau, is a species of wild cattle found in Southeast Asia. Banteng have been domesticated in several places in Southeast Asia, and there are around 1.5 million domestic banteng, which are called Bali cattle. These animals are used as working animals, and for their meat.[2] Bali cattle have also been introduced to Northern Australia, where they have established stable feral populations.[3]

Contents

Distribution and subspecies

Characteristics

The banteng is similar in size to domestic cattle, being 1.55 to 1.65 m (61 to 65 in) tall at the shoulder, and weighing 600 to 800 kg (1,300 to 1,800 lb).[4] It exhibits sexual dimorphism, allowing the sexes to be readily distinguished by colour and size. In mature males, the short-haired coat is blue-black or dark chestnut in colour, while in females and young it is chestnut, with a dark dorsal stripe. Both males and females have white stockings on their lower legs, a white rump, a white muzzle, and white spots above the eyes. The build is similar to that of domestic cattle, but with a rather slender neck and small head, and a ridge on the back above the shoulders. The horns of females are short and tightly curved, pointing inward at the tips, and those of males arc upwards, growing 60 to 75 cm (24 to 30 in) long, and being connected by a horn-like bald patch on the forehead.

Behaviour

Female

Banteng live in sparse forest where they feed on grasses, bamboo, fruit, leaves and young branches. The banteng is generally active both night and day, but in places where humans are common they adopt a nocturnal schedule. Banteng tend to gather in herds of two to thirty members.

Cloning

The banteng is the second endangered species to be successfully cloned, and the first to survive for more than a week (the first was a gaur that died two days after being born).[5][6] Scientists at Advanced Cell Technology in Worcester, MA, U.S. extracted DNA from banteng cells kept in the San Diego Zoo's "Frozen Zoo" facility, and transferred it into eggs from domestic cattle, a process called somatic cell nuclear transfer. Thirty embryos were created and sent to Trans Ova Genetics, which implanted the fertilized eggs in domestic cattle. Two were carried to term and delivered by Caesarian section.[7] The first was born on April 1, 2003, and the second two days later. The second was euthanized[8], but the first survived and, as of September 2006, remains in good health at the San Diego Zoo.

Banteng in Australia

Overview

The domesticated form of the banteng was first introduced to Australia in 1849 with the establishment of a British military outpost on the Cobourg Peninsula called Port Essington. Twenty animals were taken to the Western Arnhem Land, in current day Northern Territory, as a source of meat. A year after the outpost’s establishment, poor conditions including as crop failure and tropical disease led to its abandonment. With the departure of British troops, the banteng were released from their grazing pastures and allowed to form a feral population.[9] By the 1960’s, researchers realized that a population of about 1,500 individuals had developed in the tropical forests of the Cobourg Peninsula.[10]

Since their introduction in 1849, the population has not strayed far from its initial point of domesticated life; all currently live within the Garig Gunak Barlu National Park.[11] As of 2007, the initial population had grown from only 20 in 1849 to 8,000-10,000[12] and is used exclusively for sport hunting and Aboriginal subsistence hunters.[13]

As of February 2005, the banteng population of the Cobourg Peninsula is 10,000 head, making the population in the Northern Territory the largest in the world. Before the study by Charles Darwin University, it was believed that only 5,000 pure-strain banteng survived worldwide. In their native range, the largest herd numbers less than 500.

Physiology and reproduction in Australian banteng populations

The banteng of the Cobourg Peninsula have developed slightly different life processes than their domesticated counterparts. Growth over lifetime is sexually dimorphic; males grow faster and are larger than females.[14] Furthermore, females reach maximum body mass in three to four years, while males take five to six. Sexual maturity occurs three to four years, and two to four years in males and females respectively. Fecundity also declines in older females. Breeding is seasonal, with maximum mating occurring during the months of October and November, and most births take place in the winter months of June to August. Calf mortality is high in the first six months of life, and declines quickly thereafter with increasing body size. When compared to domestic populations, it was found that increased food in captive conditions allowed respectively higher fecundity, earlier maturation, and lower juvenile mortality.[14]

Australian environmental impact

Despite being a nonnative species, the feral Australian banteng has adapted to positively interact with native avian populations. Studies have shown that mutual relationships have developed involving the removal of ectoparasites residing on the bovid body by the Torresian crow (Corvus orru). [15] This is especially notable because it is the first known relationship of such a kind, which only needed 150 years to develop, where a native bird shares a mutual symbiotic relationship with a nonnative wild mammal.

Within the Garig Gunak Barlu National Park, where practically all banteng reside, there has been limited damage due to overgrazing. They are primarily found within the monsoon forests, but cause little damage, especially when compared to feral pigs.[16] Within the forest, densities were found to be around 70 per square kilometer, and have remained near their initial introduction point 140 years ago because of the possibility that their habitat is a uniquely suitable mosaic of grassland and monsoon forest.[16] Another likely reason for their limited dispersal is the presence of fences along the southern end of the peninsula installed to manage movement of other feral species like the water buffalo.[17] Interaction with the habitat is also unclear in another aspect involving monsoonal forest succession into grasslands. [18] Within the Garig Gunak Barlu National Park researchers noticed that monsoonal seedlings were encroaching into previously well established grasslands. It is thought that the grazing by banteng limits potential fuel for grassland fires to take back monsoonal forest and spreads monsoonal seeds, but was still unclear after the study. [18]

Conservation value of Australian banteng population

Since Australian banteng are considered an invasive nonnative species, some environmental scientists believe that a complete removal of the limited population will allow previously occupied habitat to regress back to its pre-1849 state and allow native species to return. However, this thought of return to pristine conditions is not clearly favorable because of the socio-economic niche it has formed, as well as playing an integral role in helping to recover endangered wild individuals in Asia.

Small populations in northern Australian are heavily relied on as a source of income for sport hunting, as well as by aboriginal peoples. Studies revealed that as much as AU$200,000 can be made annually on hunting without damaging populace stability.[11]

The current population of banteng in Australia has become the center of debate due to the endangered status it has achieved in its native Asia. Wild banteng are incredibly rare in Asia due to loss of suitable habitat, even though they are regularly used in domestic agricultural settings as grazers. But these domestic bantengs of Southeast Asia have varying degrees of introgression from other domesticated Bos species. The Australian bantengs are derived from the domesticated form and not from the rare wild form. However, genetic studies have revealed that the Australian bantengs are identical to the Asian Bos javanicus and are therefore not crossed with other species, which is what places the Australian population in a different conservation category relative to its domesticated conspecific in Southeast Asia.

Since a small founder event occurred with only approximately 20 previously domesticated individuals, a genetic bottlenecking has inevitably occurred, causing all current individuals in Australia to be genetically similar and lacking genetic diversity due to generational inbreeding. This was proven using microsatellites, 12 in all, to determine that their inbreeding coefficient was high, F=0.58.[11] These findings were comparatively much higher than the endangered artiodactyl populations in Southeast Asia. Despite the limited genetic pool of this population, conservationists are hopeful that preservation of at-risk populations can transpire. Some have proposed a deliberate introduction of the endangered populations to the stable but nonnative Australian variety will enable viable conservation, even though it is not entirely known how it will affect Northern Territory grazing ranges.[13]

See also

  • Bos palaesondaicus
  • Gaur
  • Zebu
  • Wild Asian water buffalo
  • Aurochs

References

Stamp with bantengs from the GDR
  1. ↑ Timmins, R.J., Duckworth, J.W., Hedges, S., Steinmetz, R. & Pattanavibool, A. (2008). Bos javanicus. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 29 March 2009. Database entry includes a brief justification of why this species is of endangered.
  2. ↑ Friend, J B, Cattle of the World, Blandford Press, Dorset, 1978
  3. ↑ Endangered cattle (Banteng) find pastures new, 5th August 2005, New Scientist
  4. ↑ Ultimate ungulate page on banteng
  5. ↑ Fairfax Digital, Banteng clone leads charge for endangered animals, April 9, 2003. Visited October 12, 2009.
  6. ↑ World Environment News, Scientists clone endangered Asian banteng, April 9, 2003. Visited October 12, 2009.
  7. ↑ Advanced Cell Technology, Collaborative Effort Yields Endangered Species Clone, April 8, 2003. Visited October 12, 2009.
  8. ↑ Nature Biotechnology (subscription required)
  9. ↑ Letts, G. A., and A. W. E. L. Bassingthwaite Vos. (1979). Feral animals in the Northern Territory - Report of the Board of Inquiry. Pages. Northern Territory Government, Darwin. Taken from Brook B., Bowman D.M.J., Bradshaw C., Campbell B., Whitehead P. (2006)
  10. ↑ Letts, G. A. (1964). Feral animals in the Northern Territory. Australian Veterinary Journal Volume 40 pp.84–88. Taken From Brook B., Bowman D.M.J., Bradshaw C., Campbell B., Whitehead P. (2006)
  11. ↑ 11.0 11.1 11.2 Bradshaw CJ, Isagi Y, Kaneko S, Brook BW, Bowman DM, Frankham R (July 2007). "Low genetic diversity in the bottlenecked population of endangered non-native banteng in northern Australia". Mol. Ecol. 16 (14): 2998–3008. doi:10.1111/j.1365-294X.2007.03365.x. PMID 17614913. 
  12. ↑ Bradshaw CJA, Brook BW (2007). "Ecological-economic models of sustainable harvest for an endangered but exotic megaherbivore in northern Australia". Natural Resource Modeling 20 (1): 129–156. doi:10.1111/j.1939-7445.2007.tb00203.x. 
  13. ↑ 13.0 13.1 Bradshaw CJ, Isagi Y, Kaneko S, Bowman DM, Brook BW (August 2006). "Conservation value of non-native banteng in northern Australia". Conserv. Biol. 20 (4): 1306–11. doi:10.1111/j.1523-1739.2006.00428.x. PMID 16922247. 
  14. ↑ 14.0 14.1 Choquenot D (1993). "Growth, body condition and demography of wild banteng (Bos javanicus) on cobourg peninsula, Northern Australia". Journal of Zoology 231 (4): 533–542. doi:10.1111/j.1469-7998.1993.tb01936.x. 
  15. ↑ J. A. Bradshaw, Corey (2006). "Rapid development of cleaning behaviour by Torresian crows Corvus orru on non-native banteng Bos javanicus in northern Australia". Journal of Avian Biology 37: 409. doi:10.1111/j.2006.0908-8857.03595.x. 
  16. ↑ 16.0 16.1 Bowman DMJS, Panton WJ (1991). "Sign and habitat impact of Banteng (Bos-javanicus) and pig (Sus-Scrofa) Cobourg Peninsula, Northern Australia". Australian Journal of Ecology 16 (1): 15–17. doi:10.1111/j.1442-9993.1991.tb01477.x. 
  17. ↑ Brook BW, Bowman DM, Bradshaw CJ, Campbell BM, Whitehead PJ (September 2006). "Managing an endangered Asian bovid in an Australian National Park: the role and limitations of ecological-economic models in decision-making". Environ Manage 38 (3): 463–9. doi:10.1007/s00267-005-0157-7. PMID 16736298. 
  18. ↑ 18.0 18.1 Bowman, DMJS; Panton, WJ; McDonough, L (1990). "Dynamics of Forest Clumps on Chenier Plains, Cobourg Peninsula, Northern Territory". Australian Journal of Botany 38: 593. doi:10.1071/BT9900593. 

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