Turtle Size Matters

The maximum body size of Elongated tortoise (Indotestudo elongata) is relevant from evolutionary
and ecological perspectives, and knowledge of upper asymptotic size is a necessary prerequisite for understanding patterns of growth (Platt and Rainwater 2015. Herpetol. Rev. 46:31–33 and references therein). Indotestudo elongata is a medium-sized tortoise occurring from Nepal and northeastern India, east through Bangladesh, Myanmar, Thailand, Laos, Cambodia, and Vietnam, and south into Peninsular Malaysia (Ernst and Barbour 1989. Turtles of the World. Smithsonian Institution Press, Washington, D.C. 313 pp.). Despite this extensive geographic distribution, the natural history of I. elongata remains poorly studied. We here report a new record for maximum carapace length (CL) in I. elongata.

Carapace and plastron of a record-sized indotestudo elongata (♀) photographed at an encampment near Nankathu Cave, Rakhine State, Myanmar. The tortoise was eaten by villagers after being har- vested in the adjacent Rakhine Yoma Elephant Sanctuary. (c) Khin Myo Myo/WCS

Carapace and plastron of a record-sized indotestudo elongata (♀) photographed at an encampment near Nankathu Cave, Rakhine State, Myanmar. The tortoise was eaten by villagers after being harvested in the adjacent Rakhine Yoma Elephant Sanctuary. (c) Khin Myo Myo/WCS

On 23 May 2010, Khim Myo Myo from the Wildlife Conservation Society obtained the carapace and plastron of a female (concavity absent on plastron) I. elongata from villagers living near Nankathu Cave (17.86056°N; 94.94898°E; India-Bangladesh Datum) on the eastern boundary of the Rakhine Yoma Elephant Sanctuary (RYES) in Rakhine State, Myanmar. The tortoise was reportedly found near the village inside the eastern boundary of RYES and harvested for domestic consumption about one month prior to our visit.

The habitat in this area is characterized by steep, rugged terrain with scattered evergreen and deciduous trees growing amidst dense bamboo (Melocanna baccifera) brakes (Platt et al. 2010. Chelon. Conserv. Biol. 9:114–119). Mast fruiting of M. baccifera, followed by widespread culm dieback occurred during 2007–2009 (Platt et al. 2010. Bamboo Sci. Cult. 23:1–12) and most standing bamboo was dead at the time of our visit.

Villagers used a machete-like knife to extract the meat of the tortoise by separating the carapace from the plastron, damaging the plastral bridge in the process. Annuli on both the plastron and carapace exhibited considerable wear, but we nonetheless were able to count 22 annuli on the fourth right pleural scute of the carapace. We used tree calipers to measure (to nearest 1.0 mm) straight-line CL, maximum carapace width (CW), and midline plastral length (PL; from base of anal notch) of the shell. CL, CW, and PL measured 310, 210, and 245 mm, respectively. The CL of our specimen exceeds the previously published maximum CL of I. elongata (CL = 275 mm; Ernst and Barbour, op. cit.; Smith 1931. The Fauna of British India, including Ceylon and Burma. Vol. 1. Loricata and Testudines. Taylor and Francis, London. 185 pp.) by 35 mm.

We thank the Ministry of Environmental Conservation and Forestry for granting us permission to conduct research in Myanmar. This project was made possible by generous grants from Andrew Sabin and the Andrew Sabin Family Foundation. Thomas Rainwater and Lewis Medlock are thanked for providing literature and thoughtful commentary on this manuscript.

Extract from Herpetological Review 47(2), 2016; by KHIN MYO MYO (e-mail: kmyomyo@gmail.com) and STEVEN G. PLATT, Wildlife Conservation Society – Myanmar Program, (e-mail: sgplatt@gmail.com).

Scavenging

The Burmese Star Tortoise (Geochelone platynota) is a medium-sized tortoise (carapace length

[CL] to ca. 300 mm) endemic to the dry zone of central Myanmar (Platt et al. 2011. Chelon. Res. Monogr. 5:57.1–57.9 and

Female Burmese Star Tortoise (Geochelone platynota) con- suming the carcass of a Barred Button Quail (Turnix suscitator) at Minzontaung Wildlife Sanctuary in central Myanmar. Note dried wing at lower right in photograph. (c) Me Me Soe/WCS

Female Burmese Star Tortoise (Geochelone platynota) consuming the carcass of a Barred Button Quail (Turnix suscitator) at Minzontaung Wildlife Sanctuary in central Myanmar. Note dried wing at lower right in photograph. (c) Me Me Soe/WCS

references therein). Geochelone platynota was considered functionally extinct in the wild by the mid-2000s due to a combination of long-term, chronic subsistence harvesting by rural villagers and illegal collecting to supply the international pet trade (Platt et al., op. cit.). Efforts to restore a wild population by releasing captive-bred, head-started tortoises are currently (2013–present) underway at Minzontaung Wildlife Sanctuary (MWS; 21.40000°N; 95.78333°E; India-Bangladesh datum; site description available in Platt et al. 2003. Oryx 37:464–471), a protected area in central Myanmar (Platt et al. 2015. Turtle Survival 2015:28–32). Little is known concerning the ecology of G. platynota, and information on diet and foraging behavior among wild individuals is notably lacking (Platt et al. 2011, op. cit.). Platt et al. (2001. Chelon. Conserv. Biol. 4:172–177) found plant material, insect chitin, and small stones in feces obtained from four G. platynota captured at Shwe Settaw Wildlife Sanctuary, and Thanda Swe (2004. Autecology of Myanmar Star Tortoise, Geochelone platynota [Blyth, 1863]. Ph.D. dissertation, University of Mandalay, Mandalay, Myanmar. 122 pp.) observed wild G. platynota outfitted with VHF radio transmitters at MWS consuming gastropods, fungi, and leafy foliage. We here report an observation of scavenging (carrion foraging) by G. platynota in the reintroduced population at MWS.

At 0925 h on 26 June 2015, while radio-tracking reintroduced tortoises as part of a monitoring program to determine post-release dispersal at MWS, we came upon a female G. platynota (CL = 159 mm; released November 2014) consuming the dried carcass of a Barred Button Quail (Turnix suscitator). The carcass consisted of the intact skull, disarticulated wing bones with attached feathers, and part of the sternum, with pieces of dried
flesh adhering to some bones. The remains of an egg beside the carcass (size and coloration consistent with T. suscitator) led us to speculate the quail was incubating a clutch when killed and partially consumed by a predator. When found, the tortoise was consuming a wing with attached feathers (Fig. 1), but ceased feeding
as we approached. We measured and weighed the tortoise before returning it to the carcass (ca. 5 minutes), at which time it ambled off into the surrounding scrub. Although our observation is apparently the first of G. platynota scavenging carrion in the wild, Thanda Swe (op. cit.) witnessed captive G. platynota at the Yadanabon Zoological Gardens in Mandalay, Myanmar consuming a decomposing Russell’s Viper (Vipera russelli) tossed into their enclosure, and in the past, poachers reportedly captured G. platynota in pitfall traps baited with odiferous carrion (Platt and Platt 2014. Burmese Star Tortoise Conservation in Myanmar.

Report to Wildlife Conservation Society, Bronx, New York. 46 pp.). Taken together, these reports suggest carrion is opportunistically taken by foraging G. platynota when available. In addition to G. platynota, scavenging has been reported in a number of other terrestrial and aquatic chelonians (Ernst and Lovich. 2009. Turtles of the United States and Canada. 2 nd edition. Johns Hopkins University Press, Baltimore, Maryland. 827 pp. and
references therein), and in general, is probably more prevalent than usually recognized (DeVault et al. 2003. Oikos 102:225–234). However, given the limitations of traditional dietary studies that rely heavily on fecal and stomach contents analyses, scavenging can be difficult to distinguish from predation (DeVault et al., op.
cit.) except through direct observation (Walde et al. 2007. South-west. Nat. 52:147–149) or under unusual circumstances (e.g., Platt et al. 2010. Can. Field-Nat. 124:265–267; Platt and Rainwater 2011. J. Kansas Herpetol. 37:8–9). Because of these inherent challenges, opportunistic field observations such as ours are valuable in understanding the role of scavenging as a trophic pathway (Logan and Montero 2009. Herpetol. Rev. 40:352).

Although difficult to detect, scavenging is nonetheless beneficial from the standpoint of individual fitness and can make important contributions to the diet (Bauer et al. 2005. Southwest. Nat. 50:466–471) because
carrion is an energetically rich food source that can be safely obtained without the cost of capturing and subduing prey (DeVault and Krochmal. 2002. Herpetologica 58:429–436). Even dried carcasses such as the Button Quail we observed being consumed by G. platynota are an excellent source of calcium and phosphorous (Walde et al., op. cit.). Of course, carrion consumption also entails certain costs; most notably scavengers must compete with decomposers, and also risk exposure to toxins and disease-causing microbes in carrion (DeVault et al., op. cit.).
We thank the Ministry of Environmental Conservation and Forestry for granting us permission to conduct research in Myanmar, and staff of Minzontaung Wildlife Sanctuary for assistance with this project. Research in Myanmar was made possible by generous grants from Andrew Sabin and the Andrew Sabin Family Foundation, Helmsley Charitable Trust, and Panaphil Foundation. We thank Rob Tizard for assistance with identifying the
quail carcass, Andrew Walde for literature, and Lewis Medlock for thoughtful commentary on this manuscript.

Extract from Herpetological Review 47(2), 2016; by ME ME SOE, Turtle Survival Alliance – Myanmar Program, (e-mail: memesoetsa@gmail.com); SAN SAN NWE, Nature and Wildlife Conser-
vation Division of Ministry of Environment, Conservation and Forestry, Minzontaung Wildlife Sanctuary, Natowgyi Township, Myanmar (e-mail: tortoiselady@yahoo.com); STEVEN G. PLATT, Wildlife Conservation Society – Myanmar Program, (e-mail: sgplatt@gmail.com); THOMAS R. RAINWATER, Tom Yawkey Wildlife Center & Baruch Institute of Coastal Ecology and Forest Science (e-mail: trrainwater@gmail.com).

By | 2017-05-19T09:58:11+00:00 October 6th, 2016|Landscape, Lower Chindwin, News Blogs, Wildlife, Reptiles, WCS Myanmar|0 Comments

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