The mangrove terrapin, Batagur baska Gray, 1831, inhabits coastal rivers, estuaries, and mangrove swamps from eastern India and Bangladesh, and eastward to Myanmar and possibly western Thailand. The recently recognized closely related species Batagur affinis occurs in southern Thailand, Cambodia, southern Vietnam, peninsular Malaysia, and Sumatra (Ernst and Barbour 1989; Iverson 1992; Praschag et al. 2007). Populations of both species have drastically declined throughout this range due to a combination of chronic egg-collecting, overharvesting of adults, destruction of nesting habitat, and clearance of mangrove swamp forest (Das 1997; Moll 1997). Consequently, B. baska (sensu lato, including B. affinis) is considered Critically Endangered by the International Union for Conservation of Nature and Natural Resources (IUCN; 2004).

There is little information available on the current distribution or conservation status of B. baska in Myanmar (Platt et al. 2000; Thorbjarnarson et al. 2000a). Historic accounts indicate that B. baska was once common in the Ayeyarwady Delta where large numbers nested on offshore islands at the river mouth (Theobald 1868; Maxwell 1911), but this population was extirpated by chronic egg-collecting (Thorbjarnarson et al. 2000b). Museum specimens collected during the late 1800s and early 1900s are available from the Salween and Sittaung rivers (Iverson 1992); although, the current status of these populations has yet to be investigated. Given the paucity of recent records, the IUCN (2004) regards B. baska as regionally extinct in Myanmar. However, J.A. Salter (unpubl. data, 1983) and Platt et al. (2007) received apparently reliable descriptions of B. baska from villagers inhabiting the coast of Rakhine State, suggesting the IUCN conclusion is somewhat premature. Herein we provide additional recent records of B. baska from Myanmar, and comment on the role of local religious beliefs and war zones (sensu Martin and Szuter 1999) in the continued persistence of these populations.

We conducted field surveys for B. baska in coastal regions of Mon State, and Tanintharyi and Ayeyarwady Divisions from January through July 2004. The coastal regions of Myanmar are characterized by extensive mangrove wetlands; although, these have been severely degraded in many areas as a result of fuel-wood cutting and conversion to rice fields (Tin Maung Kyi 1992). Detailed descriptions of coastal habitats in Myanmar are provided elsewhere (J.A. Salter, unpubl. data, 1983; Tin Maung Kyi 1992; Thorbjarnarson et al. 2000a).

During this survey, we obtained information on the local occurrence and exploitation of B. baska through interviews with fishermen, turtle-egg collectors, and villagers. Such individuals are generally excellent sources of information on the local chelonian fauna, especially species of cultural or economic significance (Thirakhupt and van Dijk 1994; Platt et al. 2004). Available specimens of B. baska were photographed, and the following morphometric data recorded: straight-line carapace length (CL), maximum carapace width (CW), plastron length (PL), and shell depth (SD). Additionally, we accompanied informants to specific areas where B. baska were captured to obtain habitat information. Geographic coordinates were determined with a Garmin^® GPS 12 (Table 1; Fig. 1).

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Table 1. Coordinates of localities mentioned in the text. Numbers correspond to Fig. 1.

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We also searched ponds at Buddhist pagodas for B. baska. A central tenant of Buddhism is that by releasing animals destined to be killed, an individual accrues merit and is rewarded by a higher incarnation during a future life (Annandale and Shastri 1914; Harrer 1953). In keeping with this belief, worshipers at Buddhist pagodas frequently release turtles into pagoda ponds (Annandale and Shastri 1914), where a careful search often yields species of conservation concern (van Dijk 1997; Kuchling et al. 2004; Platt and Kalyar, pers. comm., 2004). However, because the provenance of these turtles is usually unknown, distributional records based on pagoda ponds must be interpreted with caution (Kuchling et al. 2004).

We verified the occurrence of B. baska at 1 location in Mon State and 2 localities in Tanintharyi Division, where we obtained the carapace of a recently killed B. baska, examined a clutch of eggs, and were shown photographs of a large female recently captured by fishermen. The carapace (CL = 528 mm; CW = 424 mm) was obtained from fishermen residing in Khaw Za Town, a fishing village on the border between Mon State and Tanintharyi Division; the turtle was captured nearby on 11 January 2004 and consumed shortly thereafter by villagers. Security considerations prevented us from visiting Khaw Za Town, but according to fishermen, B. baska is common in the area and regularly taken incidental to other fishing activities; some are eaten by villagers, while others are exported to Thailand with shipments of illegally felled timber. Villagers attribute the local abundance of B. baska to an ongoing armed conflict between government forces and Mon insurgent groups, which discourages fishing in many areas. Additionally, Mon insurgents restrict access by fishermen to most areas under their control.

We accompanied an egg collector to a B. baska nesting area on Pyin Won Beach along the Tanintharyi River on 5 February 2004. This individual excavated a single nest containing 12 eggs that were collected and later eaten. Nesting reportedly takes place from December through February, and our informant claimed to harvest up to 10 nests annually from small beaches along the lower reaches of the Tanintharyi River. Because female B. baska are known to partition a single clutch among as many as 3 holes (Moll and Moll 2004), it is likely these nests represent the reproductive efforts of less than 5 females. Other villagers likewise reported collecting eggs from these beaches, and it is probable that few if any nests survive to hatching. Additional nesting beaches are thought to occur further upstream, but the presence of Mon insurgents deters egg collectors from entering this area.

Additionally, the residents of Sinzeik Village provided us with photographs of a large (CL ca. 550–600 mm) female B. baska captured after it became entangled in a fishing net set in the Dawei River, approximately 38 km upstream from the river mouth. The turtle was captured on 26 January 2004 and released the following day. Fishermen stated that mangrove terrapins are extremely rare in the Dawei River and to capture one is considered a harbinger of good fortune. Batagur baska is locally regarded as a “spirit turtle” (= nat leik) capable of shape-shifting (i.e., transforming itself into another species of animal or even a person). For this reason villagers believe that misfortune will befall those who intentionally harm mangrove terrapins. In order to assuage the captured terrapin, ensure future success in fishing, and bring wealth to the village, a ceremony is held in which a mixture of jewels and water is poured over the turtle before returning it to the river.

Mangrove terrapins also reportedly occur in the Par Chan River, which separates southern Tanintharyi Division from Thailand, and its tributary creeks. According to inhabitants of the riverside villages of Thaung Phyu and Kan Paw Gyi, juvenile B. baska are frequently taken in crab traps placed beneath mangrove trees and baited with salted fish. Small terrapins are generally released, while larger specimens are kept for local consumption. Interestingly fishermen have never encountered adult terrapins, suggesting the river serves primarily as nursery habitat for young turtles.

We obtained only 1 record of B. baska from Ayeyarwady Division; fishermen in Wet Bu Village reported the inadvertent capture of an adult mangrove terrapin in the Tha Baung River during January 2004. The turtle became entangled in a shad (Tenualosa ilisha) net and was released the following day in accordance with the local belief that failure to do so would bring misfortune to the village. Although occasionally taken in fishing nets (1–2 turtles/y), fishermen regard B. baska as uncommon in the Tha Baung Estuary. Our surveys elsewhere in Ayeyarwady Division failed to find any evidence for the continued occurrence of B. baska.

Finally, we examined an adult female B. baska (CL = 558 mm; CW = 444 mm; PL = 537 mm; SD = 231 mm) inhabiting a pond on the grounds of Botahtaung Pagoda in Yangon. The CL of this turtle approached the maximum CL (600 mm) reported for B. baska (Ernst and Barbour 1989). We are unaware of any reliable means to estimate the age of tropical turtles (Wilson et al. 2003), but the large body size, lack of distinct pigmentation patterns, and fused appearance of the carapacial scutes suggested this individual was quite old. Moreover, a monk residing at the pagoda stated that the turtle had lived in the pond for “more than 30 years”. The provenance of this turtle is unknown, but we speculate that it originated from the now extinct (or nearly so) population that formerly inhabited the lower Ayeyarwady Delta (Maxwell 1911; Thorbjarnarson et al. 2000a). Botahtaung Pagoda is situated on the banks of the Yangon River, a distributary of the much larger Ayeyarwady River; a wharf provides easy access to river traffic, and the pagoda is a popular destination for river-going pilgrims from the delta region.

In conclusion, this survey and others (Platt et al. 2007) indicate that small populations of B. baska persist in coastal regions of Rakhine and Mon States and Ayeyarwady and Tanintharyi Divisions of Myanmar. As reported by Platt et al. (2007), a small number of B. baska probably occur near Ramree Island in Rakhine State, but owing to the continued harvest of eggs and adults, the long-term survival of this population is doubtful. Although the large population that once nested at the mouth of the Ayeyarwady River was decimated by the late 1980s (van Dijk 1997; Thorbjarnarson et al. 2000a), our survey suggests that small numbers remain in the Tha Baung River and its tributaries. Given the intense levels of fishing activity in this river and the risk of drowning associated with the widespread use of fishing nets (Platt et al. 2003a), the viability of this population must be considered tenuous at best.

The last stronghold of B. baska in Myanmar appears to be in Tanintharyi Division where a combination of local religious beliefs and areas of armed conflict confer varying degrees of protection on remaining populations. Religious beliefs protecting B. baska are strong but localized in Tanintharyi. We noted a similar situation in central Myanmar where the Burmese star tortoise (Geochelone platynota) figures prominently in the local practice of nat worship, and villagers refrain from harvesting them for fear of supernatural retribution (Platt et al. 2003b). Unlike the more sedentary tortoises, however, B. baska often traverse great distances between foraging and nesting habitats (Moll 1980; Platt et al. 2003a), and therefore localized beliefs prohibiting capture offer only limited protection.

Most important for the continued survival of mangrove terrapins in Tanintharyi Division and parts of adjacent Mon State is the existence of areas where armed conflict between government forces and insurgent groups has been underway for many years. These contested areas are uninhabited, and fishermen can enter only a great personal risk. War zones, defined as the no-man's-land between warring groups (Martin and Szuter 1999) often function as de facto nature reserves and allow the persistence of wildlife populations that would otherwise succumb to hunting pressure. War zones served as important source populations for large mammals in presettlement North America (Hickerson 1965; West 1995; Martin and Szuter 1999), and modern examples include the demilitarized zone on the Korean peninsula (Higuchi et al. 1996; Kim 1997) and strife-torn regions of central Liberia, West Africa (Huffman 2004). Similar to our observations, Kuchling et al. (2006) found that 1 of only 2 surviving populations of Burmese roofed turtle (Kachuga trivittata) occurred in an insurgent stronghold near Mandalay where, until recently, government control was tenuous.

Finally, it should be noted that the taxonomic status of B. baska in Myanmar is currently unresolved. In a recent investigation based on mitochondrial DNA, Praschag et al. (2007) found that B. baska from Indonesia and Malaysia are distinct from those in the Sundarbans region of India and Bangladesh and concluded that B. baska collectively includes at least 2 distinct species of large estuarine turtles. Based on similarities in the breeding coloration of males, Praschag et al. (2007) suggest that B. baska in Myanmar are most likely conspecific with populations in the Sundarbans. However, given the proximity of Tanintharyi Division to Malaysia, it is possible that both species are present in Myanmar. Because B. baska populations in India and Bangladesh are reduced to scattered individuals and no longer considered viable (Rashid and Swingland 1997), populations remaining in Myanmar, and particularly those along the eastern coast (Rakhine State and Ayeyarwady Division) are of obvious global conservation significance. Therefore both in- and ex situ conservation efforts directed at B. baska populations in Myanmar should be accorded high priority by conservation agencies.