Asian tortoise (Manouria emys)

Description

What’s the World’s Favourite Species?

Asian tortoise fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Asian tortoise description

This tortoise is the largest inhabiting Asia, and the fourth largest in the world ⁽⁴⁾. Two subspecies are currently recognised: M. e. emys is commonly known as the Asian brown tortoise, and is characterised by a light to dark brown upper shell (carapace); while M. e. phayrei is commonly known as the Burmese brown tortoise, and is larger and darker in colour, having a charcoal to black upper shell (carapace) ^{(2) (5)}. The forelimbs have five large claws and are covered on the front with large, heavy, overlapping scales. By contrast, the hindlimbs end in four pointed claws and bare a conspicuous cluster of very large tubercular scales on the thigh either side of the tail. These are so large that the species is sometimes referred to as the six-footed tortoise ^{(5) (6)}.

Also known as

Asian brown tortoise, Asian giant tortoise, black giant tortoise, Burmese brown tortoise, Burmese mountain tortoise, six-legged tortoise.

French

Tortue Brune.

Size

M. e. emys carapace length: up to 50 cm ⁽²⁾

M. e. emys weight: up to 20 kg ⁽²⁾

M. e. phayrei carapace length: up to 60 cm ⁽²⁾

M. e. phayrei weight: up to 37 kg ⁽²⁾

Asian tortoise biology

Although not a particularly social animal, the Asian tortoise seems to have more complex vocalisations and other communication methods than other tortoises ^{(2) (8)}. Males engage in vocal disputes and aggressive behaviour to discourage rivals from courting nearby females. The rather elaborate courtship involves head-bobbing and ‘fixation’ by the male, in which males fully extend their head and neck and keep it pointed towards the female as they move around ⁽²⁾. ‘Trailing’ is another courtship behaviour employed by the male prior to mounting, involving the male following very closely behind the female, and both males and females vocalise during courtship ^{(2) (6)}.

The Asian tortoise is unique among turtles and tortoises in building a nest on the surface of the ground, and in providing maternal protection of the eggs ⁽⁹⁾. For a few days before laying, the female gathers up leaves and debris into a mound on which to place her clutch ⁽²⁾. Unlike most tortoises, which use their hindlimbs to excavate nest sites, Asian tortoises use their forelimbs to ‘backsweep’ surface leaf-litter ^{(2) (8)}. Reported clutch sizes in captivity range from 21 to 53 eggs, which the female then covers with vegetation and guards, frequently piling more vegetation on top. If the eggs are threatened by a potential predator, the female will first attempt to drive them away by pushing and biting, but if this fails, she then defends the eggs by sprawling her body over them ⁽²⁾. This behaviour normally lasts just a few days following egg-laying, although up to six weeks of nest-guarding has been recorded ⁽⁶⁾. No other turtle or tortoise exhibits this high level of parental care and protection. It is thought that this behaviour helps protects the eggs by distracting and confusing the predators, and that frequently adding material to the nest may also help conceal the scent of the eggs ⁽²⁾.

The Asian tortoise is chiefly herbivorous, typically feeding on grasses, vegetables, leaves, seedlings, herbs, fruits and fungi, although invertebrates and amphibians have occasionally been recorded in the diet ^{(2) (6)}.

Asian tortoise range

The Burmese brown tortoise is distributed from Assam in India, through Burma and Bangladesh to northern and west-central Thailand, while the Asian brown tortoise reportedly occurs in southern Thailand, Peninsula Malaysia, Sumatra and Borneo ^{(6) (7)}. However, records of specimens with characteristics of the Asian brown tortoise are found as far northwest as Assam in India, and an intergrade between the two subspecies has been reported from southern Thailand to northern Malaysia, and also in Bangladesh. Thus, the true distribution of each subspecies may require further research and revision ⁽⁶⁾.

Asian tortoise habitat

The Asian tortoise inhabits temperate moist, broadleaf forest and tropical evergreen rainforest that experience monsoon rains, typically in upland areas ^{(2) (7) (8)}. Furthermore, this tortoise never wanders far from water ⁽²⁾, and spends most of the warmer parts of the day soaking in pools or in the shade, out of the sun’s rays ⁽⁵⁾.

Asian tortoise status

Classified as Endangered (EN) on the IUCN Red List 2006 ⁽¹⁾, and listed on Appendix II of CITES ⁽³⁾.

Asian tortoise threats

Like other Asian turtles and tortoises, this species is severely threatened by over-harvesting and exploitation for the food and pet trade, compounded by habitat destruction. Most records indicate that Asian tortoise populations are sparse and extremely fragmented ⁽⁶⁾. Sadly, being such a large species, the Asian tortoise is a relatively easy target for hunters and collectors ⁽⁴⁾, and its fairly high market value makes it a much sought after species ⁽²⁾.

Asian tortoise conservation

International trade is controlled by the Asian tortoise’s listing on CITES Appendix II ⁽⁶⁾. However, despite the species being uplisted from ‘Vulnerable’ to ‘Endangered’ on the IUCN Red List in 2000, the legal export quota from Peninsula Malaysia was raised from 50 wild caught specimens in 1999, to 200 in 2000, and to 500 in 2002 ^{(3) (6)}. In 2006, this quota was reduced to 400 ⁽³⁾, but this still seems too high for a species facing possible extinction. Although imports are now totally banned in the European Community, this has only served to shift the trade towards Japan and the U.S. ⁽⁶⁾. The Asian brown tortoise (M. e. emys) is legally protected in Sabah, Malaysia, under the Wildlife Conservation Enactment 1997, and a license is required from the director of the Wildlife Department to hunt or collect wild specimens ⁽⁶⁾.

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more

For more information on the Asian tortoise see:

• Høybye-Mortensen, K. (2004) The tortoise Manouria emys emys: behaviour and habitat in the wild (PhD Thesis). University of Southern Denmark, Online. Available at:
  http://hjem.get2net.dk/jagge/emys/
• Animal Diversity Web:
  http://animaldiversity.ummz.umich.edu/site/accounts/information/Manouria_emys.html

Authentication

Glossary

Herbivorous

Diet comprises only vegetable matter.

Intergrade

Animals/plants that seem to blend characteristics of subspecies.

References

1. IUCN Red List (October, 2006)
   http://www.iucnredlist.org
2. Animal Diversity Web (December, 2006)
   http://animaldiversity.ummz.umich.edu/site/accounts/information/Manouria_emys.html
3. CITES (December, 2006)
   http://www.cites.org
4. Sandalwood Herpetology Club (December, 2006)
   http://www.educationcentral.org/sandalwood/herpetology/manouria.htm
5. McKeown, S. (1990) Asian Brown Tortoise, Manouria emys. Tortuga Gazette, 33(6): 3 - 5. Available at:
   http://www.tortoise.org/archives/manemys2.html
6. Høybye-Mortensen, K. (2004) The tortoise Manouria emys emys: behaviour and habitat in the wild (PhD Thesis). University of Southern Denmark, Online. Available at:
   http://hjem.get2net.dk/jagge/emys/
7. Eggenschwiler, U. (2003) Success at Keeping and Breeding the Little-known Burmese Brown Tortoise. Reptilia, 29: 43 - 50. Available at:
   http://www.reptilia.net/articulos_ing/029.pdf
8. California Turtle and Tortoise Club (Archives): The Management and Breeding of the Asian Forest Tortoise (Manouria emys) in Captivity (December, 2006)
   http://www.tortoise.org/archives/manouria.html
9. World Chelonian Trust (December, 2006)
   http://www.chelonia.org/Articles/Memysemysnesting.htm