Asian forest tortoise

The Asian forest tortoise (Manouria emys), also known commonly as the Mountain tortoise or Burmese Brown Mountain tortoise, is a species of tortoise in the family Testudinidae. The species is endemic to Southeast Asia. It is believed to be among the most primitive of living tortoises, based on molecular and morphological studies.

Asian forest tortoise
Manouria emys from Kaeng Krachan National Park in Thailand
Conservation status
Critically Endangered  (IUCN 3.1)[1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Testudines
Suborder:	Cryptodira
Superfamily:	Testudinoidea
Family:	Testudinidae
Genus:	Manouria
Species:	M. emys
Binomial name
Manouria emys (Schlegel & S. Müller, 1844)
Synonyms[2]
List Testudo emys emys Testudo emys Schlegel & S. Müller, 1840 Testudo emydoides A.M.C. Duméril, Bibron & A.H.A. Duméril, 1851 Manouria fusca Gray, 1854 Teleopus luxatus LeConte, 1854 Manouria emydoides — Strauch, 1862 Manouria emys — Strauch, 1862 Manouria luxata — Strauch, 1862 Testudo (Scapia) falconeri Gray, 1869 Scapia falconeri — Gray, 1870 Manuria emys — Lydekker, 1889 Geochelone emys — Loveridge & E. Williams, 1957 Manouria emys emys — Obst, 1983 Geochelone emys emys — Gosławski & Hryniewicz, 1993 Testudo emys emys — Paull, 1999 Testudo emys phayrei Testudo phayrei Blyth, 1853 Testudo (Scapia) falconeri — Gray, 1869 Scapia falconeri — Gray, 1870 Scapia phayrei — Gray, 1871 Testudo nutapundi Reimann, 1979 Geochelone nutapundi — Groombridge, 1982 Manouria emys nutapundi — Obst, 1983 Manouria emys phayrei — Bour, 1984 Geochelone (Manouria) emys phayeri Alderton, 1988 (ex errore) Geochelone emys nutapundi — Gosławski & Hryniewicz, 1993 Manouria nutapundi — Obst, 1996 Manouria emys phayeri — Paull, 1997 Manouria emys phayre Das, 2001 (ex errore) Manouria emys phareyi Ferri, 2002 (ex errore)

Taxonomy

There are two recognized subspecies: M. e. emys occurring in southern Thailand, Malaysia, Sumatra, Borneo; and M. e. phayrei, occurring from northwestern Thailand to northeastern India. The latter was named after Sir Arthur Purves Phayre (1812–1885), British Army officer in India who became Commissioner of British Burma.^[3]

Based on a variety of phylogenetic characteristics, the genus Manouria is regarded as comparatively primitive and basal to other Testudinidae.^[4]

Description

Illustration by George Henry Ford

The Asian forest tortoise is the largest tortoise in mainland Asia. The largest adults of the northern subspecies, Manouria emys phayrei, can reach 25 kg (55 lb) in the wild and much more in captivity.It has a broad, flattened upper shell and a large lower shell, with distinctive features on its head, limbs, and skin that set it apart from other tortoises.

The carapace is considerably depressed (flattened), its depth less than half its length. Anterior and posterior margins are reverted (upturned) and strongly serrated (toothed). A nuchal (neck) shield is present, along with two supracaudal (above the tail) shields. Dorsal shields show concentric striations (grooves) and are often concave. Vertebral shields are much broader than long and at least as broad as costals (side plates). The lower shell (plastron) is large, with the gular region (throat area) produced (slightly extended) and typically notched (indented). The hind lobe (rear section) is deeply notched (indented). Pectoral shields may be widely separated or joined by a short median suture (seam). The axillary (armpit) shield is very small, while the inguinal (groin) shield is large. The head is moderate in size, featuring two large prefrontal shields and a large frontal shield. The beak is not hooked. Jaws are feebly denticulated (weakly toothed), with a strong median ridge (raised line) on the upper jaw’s alveolar surface (inner surface). Anterior forelimb surfaces have large, bony, pointed, imbricate tubercles (overlapping bumps) in four or five longitudinal series. Hind limbs bear large bony tubercles (bumps) on the plantar surface (sole), with larger, conical, spur-like tubercles (bumps) on the heel and a group of even larger conical tubercles (bumps) on each side of the thighs’ posterior. Adults are dark brown or blackish. Juveniles have a yellowish-brown carapace with dark-brown markings.^[5]

Carapace from Kaeng Krachan National Park in Thailand.

Plastron from Kaeng Krachan National Park in Thailand.

Distribution

The Asian forest tortoise occurs in Bangladesh, Cambodia, India, Indonesia, Malaysia, Myanmar, Thailand, and Vietnam.^[1]

Diet

Manouria emys has been observed in the wild to consume whole fungi, shoots of koster's curse (Miconia crenata), leaves and petioles of elephant ears (Alocasia sarawakensis and Alocasia scabriuscula), shoots of Begonia sp., shoots of Phrynium sp., shoots of vegetable fern (Diplazium esculentum), and flowers of wild ginger (Etlingera coccinea). Most commonly eaten were plants of the genus Alocasia, with individuals observed standing nearly vertical to reach leaves. In captivity, individuals have accepted a wide variety of food, predominantly being herbivorous but occasionally consuming frogs, snails, or carrion when presented.^[6]

Reproduction

Manouria emys is the only tortoise which lays its eggs above ground in a nest, which the female constructs of leaf litter. The female uses both front and rear legs to gather material for the nest and lays up to 50 eggs deep inside it. She then sits on and near the nest to protect it, and will "chase" predators and intruders away.^[7]

Preliminary research has been conducted into Temperature-Dependent Sex Determination (TSD) in Manouria Emys Emys, and an estimated pivotal temperature of 29.29°C was determined. Incubation temperatures higher than this produce high rates of female hatchlings, and lower than this produce high rates of males.

A correlation was also seen between temperature and incubation time, with higher temperatures resulting in a shorter incubation time, and lower temperatures resulting in a longer incubation time. Incubation time ranged from 60 to 90 days. ^[7]