Clearing House Mechanism


Four species of tortoises are known to occur in Myanmar: Geochelone platynota, Manouria emys, Manouria impressa, and Indotestudo elongata. Of these, all are threatened to some extent by a combination of subsistence and commercial harvesting, over-collection for the pet trade, and to a lesser extent, habitat destruction. Conversion of natural vegetation to agricultural land is primarily a threat to tortoises in the Dry Zone. Elsewhere in Myanmar, tortoises often inhabit secondary vegetation that invades abandoned swidden fields, suggesting habitat destruction is a lesser threat provided tortoises can avoid subsistence hunters.
Geochelone platynota, a species endemic to the Dry Zone now appears to be “ecologically extinct” in the wild (Platt et al. 2011b). However, the species adapts well to captivity and given appropriate husbandry methods, reproduces readily. At present over 1100 are maintained in assurance colonies and plans to reintroduce G. platynota to Minzontaung Wildlife Sanctuary and perhaps elsewhere are being developed (Platt et al. 2011a).
Indotestudo elongata apparently occurs throughout much of the country in a variety of habitats ranging from desert-like scrub of the Dry Zone to moist evergreen forest in the Rakhine Yomas. Healthy populations remain in some remote areas (e.g., Rakhine Yomas; Platt & Khin Myo Myo 2009), although this tortoise is subject to subsistence harvesting wherever it occurs in close proximity to humans. Moreover, large numbers are illegally exported to markets in southern China (Platt et al. 2000). Current harvest levels are clearly unsustainable and field surveys suggest many populations are declining, particularly in the Dry Zone (Platt et al. 2001b).
The current conservation status of M. emys and M. impressa remains poorly known. Although M. emys is known from mountain ranges in western and eastern Myanmar, there are few recent records from anywhere in the country (Platt et al. 2001a). All available evidence indicates this large tortoise is subject to intense exploitation wherever found. Indeed the only recent records of known provenance are shells of tortoises eaten by villagers. Furthermore, recent confiscations of tortoises at border crossings suggest large numbers are being harvested for illegal export to China. Collectively these pressures constitute a serious threat to the continued viability of wild populations, and conservation action for M. emys is urgently warranted. There is little information on the conservation status of M. impressa and even its distribution within Myanmar is poorly known. M. impressa is apparently confined to mountain ranges in western and eastern Myanmar (Iverson 1992; Platt et al. 2001c), although only a handful of specimens exist. Shells recovered in villages and confiscations at border crossings indicate M. impressa is subject to both subsistence and commercial harvesting.

River Turtles
Two large river turtles, Batagur baska and Batagur trivittata, are known from Myanmar. Both species were historically common in the larger rivers (Thanlwin, Sittaung, Ayeyawady , and Chindwin) and estuaries of Myanmar (Thorbjarnarson et al. 2000a; Platt et al. 2006). However, because these turtles nest colonially on undisturbed sandbanks and eggs were sought for domestic consumption and sale in local markets, population declines due to chronic egg collecting were noted over 100 years ago. Moreover, fishermen ate adult turtles, the most demographically important segment of the population, and sandbank nesting habitat was destroyed by seasonal cultivation during the dry season. Consequently, these two species are considered to be among the most endangered turtles in the world (Rhodin et al. 2011). Currently, a small remnant population of B. trivittata consisting of <20 reproductive females is known to inhabit a restricted stretch of the upper Chindwin River where it is threatened by beach destruction, gold mining, and incidental take by fisheries activities (Rhodin et al. 2011; Platt et al. 2012a). The status of a smaller population found on the Dokhtawady River (tributary of the Ayeyawady ) in 2001 is unclear; however, inundation of this stretch of river by a hydropower dam does not bode well for its continued survival (Platt et al. 2005; Kuchling et al. 2006). Captive-breeding efforts have been quite successful to date, and almost 500 B. trivittata are maintained in assurance colonies at Yadanabon Zoological Garden, Lawkanandar Wildlife Sanctuary, and a remote camp on the Chindwin River. Plans to reintroduce B. trivittata in appropriate habitat are being developed. The continued existence of B. trivittata remains threatened by recurring proposals to construct a massive hydropower dam on the upper Chindwin River that would impound the only stretch of river inhabited by the last known wild population (Rhodin et al. 2011). The current status of B. baska in Myanmar is virtually unknown. Populations in the Ayeyawady River were extirpated by the late 1970s, although a few scattered individuals might yet persist (Thorbjarnarson et al. 2000a). Likewise, remnant populations might still occur in coastal mangroves of Rakhine State (Platt et al. 2007). Surveys of coastal Taninthayi Region suggest the existence of several small nesting populations in areas contested by local insurgent groups; these reports await verification (Platt et al. 2008). Captive-assurance colonies of this species are urgently needed (Platt et al. 2006).
Soft-shelled Turtles
Six species of trionychid (soft-shelled) turtles occur in Myanmar (Amyda cartilaginea, Nilssonia formosa, Chitra vandijki, and Lissemys scutata, L. punctata, and Dogania subplana), three of which are endemic (N. formosa, C. vandijki, L. scutata) and therefore of obvious conservation importance. Of the trionychids, only L. scutata is currently secure. Although widely exploited for export to markets in southern China, its small size, rapid growth rate, frequent reproduction, and ability to live in anthropogenic habitats, appear to make L. scutata one of the few turtles capable of sustaining moderate levels of harvest. All other soft-shelled turtles are heavily exploited for export to food markets in southern China (Platt et al. 2000; Kuchling et al. 2004). The high price paid by illegal wildlife traders for softshell turtles (often the equivalent of an individual’s annual income) mean it is economically worthwhile to seek out the last remaining turtles in an area. Consequently populations throughout Myanmar seem to be in a downward spiral. Moreover, populations are threatened by accidental drowning in fishing gear, destruction of nesting beaches by seasonal cultivation, and nest losses due to trampling by livestock.
Arakan Forest Turtle
The Arakan Forest Turtle Heosemys depressa is endemic to the Rakhine Hills of western Myanmar where it inhabits a variety of habitats including dense bamboo brakes, and deciduous and evergreen forest (Platt et al. 2003; 2010a & 2010b). The species remains poorly studied and even its geographic distribution has yet to be fully resolved. Earlier suggestions that H. depressa occurred in the southern Chin Hills now seem unfounded (Platt et al. 2012b). The species is heavily exploited for food by indigenous hill people, and confiscations from wildlife traders suggest some demand by markets in southern China. However, despite being considered Critically Endangered, H. depressa seems secure in remote areas of this sparsely populated region (Platt et al. 2003; 2010a & 2010b). Plans are currently underway to establish captive assurance colonies, and further field studies are warranted (Platt et al. 2011).
Burmese Eyed Turtle
The Burmese Eyed Turtle Morenia ocellata is endemic to Myanmar, although virtually nothing is known regarding its life history, distribution, or conservation status. Previously the species was thought confined to lower Myanmar, but records are available from as far north as Mandalay and the Shweli River (Iverson 1992; Platt et al. 2005). The species is generally assumed secure and has consequently received little attention although the massive numbers exported from Myanmar are cause for concern. Although apparently common in some areas, current levels of trade are clearly unsustainable and future population declines are inevitable. This situation is particularly alarming because M. ocellata is extremely difficult to maintain in captivity making effective ex-situ conservation unlikely. Basic field studies of this poorly known species are urgently needed (Platt et al. 2000).

Big-headed Turtle
The Big-headed Turtle Platysternon megacephalum is confined to hill ranges of eastern Myanmar (Iverson 1992; van Dijk 1993). Because much of this area remains off-limits to biological prospecting, little is known regarding the life history or conservation status of this enigmatic species. Several large confiscations of P. megacephalum have been made suggesting trade is a significant factor in the conservation of this species. These turtles are apparently in great demand by Chinese markets. Field surveys of Shan, Mon and Kayah States are urgently needed to clarify the conservation status of P. megacephalum in Myanmar.

Marine Turtles
Large concentrations of nesting marine turtles are known from several locations along the coast of Myanmar and on offshore islands (Thorbjarnarson et al. 2000c). With few exceptions these nesting beaches are unprotected and subject to extensive egg collecting. Turtle eggs are consumed locally and also sent to more distant urban markets. Furthermore, large numbers of marine turtles drown in poorly designed shrimp trawls, become entangled in fishing gear, and succumb after ingesting anthropogenic debris such as plastic bags. Additionally, some fishing communities deliberately harvest marine turtles for food. Conservation action targeting all life stages of marine turtles and their habitats is urgently needed in Myanmar.

The Estuarine crocodile Crocodylus porosus is the only species of crocodilian known to currently occur in Myanmar. Although once common and widespread throughout coastal regions (Platt et al. 2001d; Thorbjarnarson et al. 2006), extant populations are now confined to the Ayeyawady Delta, and coastal Taninthayi and possibly Rakhine State (Platt et al. 2001d; Thorbjarnarson et al. 2006). The only viable population is found in Meinmahla Kyun Wildlife Sanctuary and adjacent reserved forests of the Ayeyawady Delta. Surveys conducted in 1999 and again in 2003 found large numbers of juveniles, suggesting population recruitment is occurring (Thorbjarnarson et al. 200b & 2006); however, more recent data are lacking and additional surveys are warranted. The conservation status of C. porosus in other coastal regions has yet to be determined, although anecdotal data suggests populations are depressed and remain subject to exploitation (Platt et al. 2001d; Thorbjarnarson et al. 2006).

The Gharial Gavialis gangeticus is the only other species of crocodilian known from Myanmar; a single adult was reportedly shot and another observed in the Shweli River in 1927. However, G. gangeticus now appears extinct in Myanmar, although a recent survey suggests a few individuals may yet remain on the upper reaches of this river (Win Ko Ko in prep). Unfortunately, present security concerns preclude fieldwork in this region. Although Crocodylus siamensis, C. palustris, and Tomistoma schlegelii have all
been said to occur in Myanmar, verified records for these species are lacking (Thorbjarnarson et al. 2006).