Manouria Emys (Schlegel and Müller 1840) – Asian Giant Tortoise, Giant Asian Forest Tortoise
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Conservation Biology of Freshwater Turtles and Tortoises: A Compilation Project ofTestudinidae the IUCN/SSC Tortoise— Manouria and Freshwater emys Turtle Specialist Group 086.1 A.G.J. Rhodin, P.C.H. Pritchard, P.P. van Dijk, R.A. Saumure, K.A. Buhlmann, J.B. Iverson, and R.A. Mittermeier, Eds. Chelonian Research Monographs (ISSN 1088-7105) No. 5, doi:10.3854/crm.5.086.emys.v1.2015 © 2015 by Chelonian Research Foundation • Published 24 February 2015 Manouria emys (Schlegel and Müller 1840) – Asian Giant Tortoise, Giant Asian Forest Tortoise CRAIG B. STANFORD1, PRATYAPORN WANCHAI2, CHUCK SCHAFFER3, RICK SCHAFFER4, AND KUMTHORN THIRAKHUPT2 1Department of Biological Sciences, University of Southern California, Los Angeles, California 90089 USA [[email protected]]; 2Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand [[email protected], [email protected]]; 313811 Tortuga Point Drive, Jacksonville, Florida 32225 USA [[email protected]]; 4University of Florida, College of Engineering, Gainesville, Florida 32611 USA [[email protected]] SUMMARY. – The Giant Asian Forest Tortoise, Manouria emys (Family Testudinidae), is the largest tortoise species in mainland Asia, with a straight carapace length (CL) of up to at least 600 mm, and mass up to 37 kg. Two subspecies, M. e. emys and M. e. phayrei, are distinguished by geographic distribution, coloration, plastral scute pattern, and maximum size. Manouria is considered to be among the most primitive of living tortoise genera. The species occurs in hilly wet forest; its diet includes green vegetation, mushrooms, bamboo shoots, and fallen fruits. Unlike most tortoises, which tend to prefer relatively arid habitats, M. emys prefers a mesic habitat and is often found in and around cool flowing streams, sitting for days in water or mud, or foraging in such habitats. Although the species is active all year round, some individuals exhibit an inactive period of up to two months in the cool dry season. The species exhibits unusual nesting activity; females build mound nests of forest floor debris, deposit large annual clutches of up to 60 eggs, and guard the nest for the early portion of incubation. Despite their size, the behavioral ecology of M. emys has been little studied. The species has apparently been extirpated in the westernmost portion of its range and is highly threatened everywhere else. Healthy populations are known to occur in a few protected areas in Thailand and Indonesia, but most remaining habitat is being rapidly degraded and destroyed, and the species continues to be collected for food and smuggled into the pet trade. DISTRIBUTION. – Bangladesh, Brunei (?), India, Indonesia, Malaysia, Myanmar, Singapore (extirpated), Thailand. From Assam in India and eastern Bangladesh in the west, through Myanmar and western Thailand, and south through peninsular Malaysia to Sumatra and Borneo in the east. SYNONYMY. – Testudo emys Schlegel and Müller 1840, Manouria emys, Manouria emys emys, Geochelone emys, Geochelone emys emys, Testudo emys emys, Testudo emydoides Duméril and Bibron in Duméril and Duméril 1851, Manouria emydoides, Manouria fusca Gray 1854, Teleopus luxatus Le Conte 1854, Manouria luxata, Testudo (Scapia) falconeri Gray 1869 (partim, nomen dubium), Testudo falconeri, Scapia falconeri. SUBSPECIES. – Currently two recognized: 1) Manouria emys emys (Asian Brown Giant Tortoise) (distribution: Brunei [?], Indonesia, Malaysia, Singapore [extirpated], Thailand), and 2) Manouria emys phayrei (Burmese Black Giant Tortoise, Burmese Mountain Tortoise) (synonymy: Testudo phayrei Blyth 1853, Scapia phayrei, Manouria emys phayrei, Testudo (Scapia) falconeri Gray 1869 (partim, nomen dubium), Testudo falconeri, Scapia falconeri, Testudo nutapundi Reimann in Nutaphand 1979, Geochelone nutapundi, Manouria emys nutapundi, Geochelone emys nutapundi, Manouria nutapundi) (distribution: Bangladesh, India, Myanmar, Thailand). STATUS. – IUCN 2014 Red List: Endangered (EN A1cd+2cd; assessed 2000); TFTSG Draft Red List: Critically Endangered (CR, assessed 2011); CITES: Appendix II (as Testudinidae spp.). Taxonomy. — Schlegel and Müller originally described and Barbour (1989), means “rare domed one”. The subspecies Testudo emys in 1840; the etymology of the specific epithet Manouria emys phayrei is named for Arthur Purves Phayre, is either from the Greek “emus”, meaning freshwater turtle Commissioner of British Burma, who collected the specimen (Ernst and Barbour 1989), or borrowed from the European Blythe (1853) described as Testudo phayrei. The genus Manouria pond turtle, Emys (Obst 1988). Manouria, according to Ernst was described as separate from Testudo by Gray (1854). 086.2 Conservation Biology of Freshwater Turtles and Tortoises • Chelonian Research Monographs, No. 5 Figure 1. Manouria emys phayrei in Kaeng Krachan National Park, Thailand. Photo by Craig Stanford. Although Schlegel and Müller (1840) described Testudo (1980) reassigned the species to Manouria, and Obst (1983) emys as a terrestrial chelonian from Sumatra, throughout its recognized T. nutapundi as M. emys nutapundi, with M. early taxonomic history the species was considered aquatic. emys emys as the nominative subspecies. Bour (1984) There was perhaps some credibility in this belief due to the resurrected the subspecies name M. e. phayrei, recognizing its species’ primitive morphology and riparian habitat. Of the nomenclatural priority over nutapundi. For a more extensive six specimens first collected, four remain in Leiden, and one examination of Manouria taxonomy, see Bour (1998). in Paris, from which Duméril and Bibron in Duméril and Manouria is considered by many authorities (e.g., Duméril (1851) described Testudo emydoides. Gray (1844) Pritchard 1979; Moll 1989) to be the most primitive genus considered T. emys to be synonymous with Geoemyda of living tortoises, based on a lack of many of the derived spinosa, as did Cantor (1847), who collected two specimens morphological features of other tortoises, such as mental from Penang, Malaysia. One of these specimens found its glands (Winokur and Legler 1975), carpal bone alignment way to London and to Gray (1860), who designated it as (Auffenberg 1966), and primitive gular scute structure M. fusca (Gray 1854). Strauch (1862) later examined and (Crumley 1982, 1984; Highfield 1990), and preference for validated Manouria as a separate genus. a wet rather than arid habitat (Crumley 1982). However, Nutaphand (1979) redescribed M. emys phayrei as Heiss et al. (2011) noted that its oropharyngeal anatomy and Testudo nutapundi (Reimann in Nutaphand 1979). Bour tongue were more similar to other derived testudinids. Le et Figure 2. Manouria emys emys in the wild in Tabin Wildlife Reserve, Figure 3. Plastrons of Manouria emys emys (left) and Manouria emys Sabah, East Malaysia (Borneo). Photo by Chuck Schaffer. phayrei (right), showing the typical lack of midline pectoral scute contact in M. e. emys. Photo by Chuck Schaffer. Testudinidae — Manouria emys 086.3 Figure 4. Historic distribution of Manouria emys in Southeast Asia. Purple lines = boundaries delimiting major watersheds (level 3 hydrologic unit compartments – HUCs); red dots = museum and literature occurrence records based on Iverson (1992) plus more recent data, and the authors’ personal data; yellow dots = historic observations where populations have likely been extirpated; broad gray line = approximate boundary between the two subspecies, north of the Thailand–Malaysia border, with M. emys phayrei to the north and M. emys emys to the south and east; green shading = projected historic native distribution based on GIS-defined level 10 HUCs constructed around verified localities and then adding HUCs that connect known point localities in the same watershed or physiographic region, and similar habitats and elevations as verified HUCs (Buhlmann et al. 2009; TTWG 2014), and adjusted based on authors’ subsequent data. al. (2006) examined the phylogenetics of the Testudinidae Thai name for the species, tao hok, and the Sabahan name, and confirmed the basal position of Manouria within the kura-kura anamkaki. The species has a fairly uniform color family, and most closely related to Gopherus, while also as adults; light brown in M. e. emys and darker brown to noting only minor differences in mitochondrial DNA patterns black in M. e. phayrei. Hatchling M. e. emys are light brown, between the two recognized subspecies, M. e. emys and M. while M. e. phayrei are nearly gray. e. phayrei. Manouria emys is Asia’s largest tortoise, with carapace Description. — Compared to most other tortoise taxa, lengths up to 600 mm and mass of up to 37 kg. Manouria M. emys has a low-domed carapace. Prominent spurs are emys phayrei is the larger of the two recognized subspecies. located in the region between the tail and rear legs, making It is distinguished from M. emys emys by somewhat larger the tortoise appear somewhat to have six legs, leading to the average maximum size and its darker color, although whether Figure 5. Manouria emys phayrei female in captive assurance colony. Figure 6. Manouria emys emys from peninsular Malaysia. Photo by Photo by Chuck Schaffer. Mark Auliya. 086.4 Conservation Biology of Freshwater Turtles and Tortoises • Chelonian Research Monographs, No. 5 the maximum recorded size for M. e. phayrei is larger than P.P. van Dijk, pers. comm.). The southern subspecies, M. e. that of M. e. emys is unclear. The two subspecies can usually emys, ranges into Malaysia, Sumatra, and Borneo, and has