Literaturdatenbank
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Platt, S. G., Moe, K., Platt, K., & Soe, M. M. (2011). An assessment of shwe settaw and minzontaung wildlife sanctuaries as reintroduction sites for the critically endangered geochelone platynota Wildlife Conservation Society.
Added by: Sarina Wunderlich (18 Nov 2012 17:43:50 UTC) |
| Resource type: Report/Documentation BibTeX citation key: Platt2011b View all bibliographic details  |
Categories: General Keywords: Geochelone, Geochelone platynota, Habitat = habitat, Indotestudo, Indotestudo elongata, Schildkröten = turtles + tortoises, Südasien = Southern Asia, Testudinidae Creators: Moe, Platt, Platt, Soe Publisher: Wildlife Conservation Society |
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| Abstract |
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Testudinidae The Myanmar star tortoise (Geochelone platynota) is a medium-sized tortoise (carapace length to 30 cm) endemic to the dry zone of central Myanmar. Geochelone platynota is classified as Critically Endangered on the IUCN Red List, and included in Appendix II of CITES. During surveys conducted from 1999 to 2001, extant wild populations were identified at three sites in Myanmar, including two protected areas (Shwe Settaw and Minzontaung wildlife sanctuaries) and village lands near Mya Leik Taung (= Emerald Turtle Mountain). Since the initial surveys, G. platynota populations have precipitously declined throughout Myanmar primarily as a result of over-collection to supply international food and pet markets. The available evidence now suggests that few if any viable populations of G. platynota remain and the species could be ecologically extinct in the wild. Recognizing that future conservation efforts hinged on developing successful captive breeding programs to supply tortoises for eventual reintroduction into protected habitats, assurance colonies of G. platynota were established at Yadanabon Zoological Gardens (Mandalay), and Minzontaung, Lawkanandar, and Shwe Settaw wildlife sanctuaries. To date these programs have enjoyed considerable success and large numbers of hatchlings are being produced each year. Consequently, these facilities will soon reach maximum capacity and there is an urgent need to initiate carefully planned and monitored reintroductions of G. platynota into suitable habitat in protected areas of Myanmar. To this end, we revisited two previously identified sites (Shwe Settaw and Minzontaung wildlife sanctuaries) known to harbor populations of G. platynota, and evaluated the potential of each area for future reintroductions of captive bred tortoises. Our specific objectives when evaluating each wildlife sanctuary were to: a. Determine if extant star tortoise populations remain in the sanctuary. b. Assess the suitability of available habitat for released tortoises. c. Identify human impacts (grazing, fuelwood cutting, etc.) on habitat and determine if these impacts pose a potential threat to reintroduced tortoises. d. Evaluate access by local villagers and determine if sites (or remote locations at each site) can feasibly be protected from incursions by potential poachers. e. Evaluate the level of security afforded by Forest Department personnel to determine if adequate post-release protection of reintroduced tortoises will be possible. f. Develop site-specific plans for reintroducing star tortoises to each sanctuary if deemed biologically and socially feasible. Shwe Settaw and Minzontaung wildlife sanctuaries (hereafter SSWS and MWS, respectively) are located within the Dry Zone of central Myanmar, a semi-arid region formed by the rain shadow of the Rakhine Yoma Mountains. Shwe Settaw Wildlife Sanctuary (20°11'N; 94°28'E) is located in Magway Division on the western edge of the central dry zone between the Man and Mon Rivers. SSWS is composed of four separate management units comprising 114,726 acres. A Buffer Zone consisting of 64,391 acres surrounds the wildlife sanctuary. Low hills and deep ravines characterize much of SSWS. The vegetation of SSWS is characterized by Indaing and Than dahat forest types. Canopy height rarely exceeds 6 m and the understory consists of scattered shrubs and dense grasses. Despite being nominally protected, shifting cultivation, illegal treefelling, and bamboo harvesting are rampant in many areas of SSWS. Minzontaung Wildlife Sanctuary (20°11'N; 94°28'E) is located in Mandalay Division, approximately 60 km southwest of Mandalay. The sanctuary was established in 1998-99 for the protection of Eld’s deer and comprises 2260 ha. The topography of MWS is dominated by Minzon Taung (=Mountain), an isolated hill mass that rises to a maximum elevation of 398 m. The vegetation of MWS has been variously described as Thorn Forest, Thorn Scrub, and Euphorbia Scrub. We conducted fieldwork in Shwe Settaw and Minzontaung wildlife sanctuaries from 4 to 14 September and 16 to 21 September 2011, respectively. Our survey coincided with the latter part of the annual wet season; intermittent rainfall, at times heavy occurred throughout the period we were in the field. To determine the conservation status of tortoises in Shwe Settaw Wildlife Sanctuary we used local hunters and their dogs to search for tortoises. Local hunting dogs were unavailable in Minzontaung Wildlife Sanctuary. During the survey we also conducted open-ended interviews of farmers, villagers, and other knowledgeable individuals regarding the local occurrence of tortoises and levels of exploitation. We consulted local Forest Department personnel regarding potential sites in each wildlife sanctuary where reintroduction of tortoises might prove feasible. We then visited each site and evaluated it on the basis of habitat suitability, accessibility by sanctuary personnel and villagers, existing infrastructure, particularly with regards to security (e.g., basecamps, guard posts, etc.), and human impacts (shifting cultivation, tree-felling, livestock grazing, etc.) in the immediate area. We encountered no star tortoises during 174 man-hours and 54 dog-hours of search effort in SSWS, contrasting markedly with our earlier survey in 1999. Similarly, interviews of local villagers also suggest G. platynota is extremely rare in the sanctuary. For example, traders have stopped making periodic visits because few if any, tortoises are available to buy, and villagers no longer consider it economically worthwhile to devote time and effort to search for star tortoises owing to their rarity. Regardless, any star tortoise opportunistically encountered in the forest is invariably collected and sold. Although scattered individuals persist in SSWS, these remaining tortoises cannot be considered a biologically viable population. We therefore conclude that Geochelone platynota is most likely “ecologically” extinct in SSWS. The conservation status of G. platynota in MWS is difficult to reliably assess. We found no wild tortoises during our reconnaissance, although this result is not unexpected given the near-impenetrable thorn scrub vegetation characteristic of the sanctuary, the cryptic habits of star tortoises, and the fact that hunting dogs were not used in our survey. Most tellingly, an intensive 10 day survey in 2008 found only a single star tortoise. This is apparently the only verified occurrence of G. platynota in the sanctuary since 2004. However, local villagers assert that star tortoises are present in the sanctuary. A high degree of protection appears to be afforded to tortoises (both G. platynota and Indotestudo elongata) in MWS by the local practice of Nat worship. In the area 4 surrounding MWS, a Nat known as the “White Horse Rider” is believed to dwell in Minzon Taung and act as the guardian of the mountain. Villagers who disregard proscriptions against disturbing tortoises are apt to suffer divine retribution. We evaluated three potential reintroduction sites in Shwe Settaw Wildlife Sanctuary: Pilgrim Road, Kai Magi Basecamp, and Kandwgyi Lake. Because of its relatively remote location with respect to existing roads and trails, absence of human disturbance, and excellent Indaing habitat, we regard the Pilgrim Road site as the most suitable location to release star tortoises in SSWS. We conducted pedestrian surveys throughout MWS to inspect tortoise habitat and identify potential release sites. Most of the sanctuary appears to constitute suitable habitat for G. platynota. Because the western sector of the sanctuary contains extensive stands of dense, second-growth vegetation with minimal evidence of human activity, the area is readily accessible from MWS HQ, and this is where most star tortoises have been found during previous surveys, we recommend establishing a release site in dense forest and scrub to the north-northwest of the sanctuary HQ and south-southeast of Minzon Taung. Our recent field assessment suggests that reintroducing star tortoises is feasible at selected sites in both Shwe Settaw and Minzontaung wildlife sanctuaries. Of the two sanctuaries, a reintroduction project at MWS probably has the greatest likelihood of success owing to locally entrenched Nat worshiping practices. Below we outline a specific protocol for reintroducing star tortoises to Shwe Settaw and Minzontaung wildlife sanctuaries. Reintroduction protocol for Geochelone platynota 1. We recommend conducting a “soft release” of star tortoises at proposed reintroduction sites, i.e., tortoises should be held in pens and allowed to become accustomed to the site prior to release. 2. A pre-release pen of about 1 ha should be constructed in the core of each release site. Typical habitat, preferably thick grass with scattered trees and shrubs should be enclosed within the pen. 3. Tortoises should be penned for at least 12-18 months prior to release to engender site fidelity and reduce the likelihood of dispersal from the release area. 4. Only subadult (ca. 3 to 7 years old) star tortoises should be used in the reintroduction project. Hatchlings and small juveniles are vulnerable to predation, and mature adults should be retained in as breeding stock in the assurance colonies. 5. Efforts must be made to prevent tortoises from associating humans with food provision. To break the association between humans and food, we recommend 5 placing food in the pens during hours of darkness (perhaps prior to daybreak), when tortoises are normally inactive. Additionally, existing natural vegetation and plantings in the holding pens could reduce the dependency of tortoises on food prepared by humans, and provide an opportunity for tortoises to become accustomed to foraging for natural foods. 6. Post-release monitoring is critical and to this end, we recommend attaching radiotelemetry transmitters to each tortoise prior to penning. Tortoises should be located daily while penned, and at least once per week (more frequently if possible) after being released. During the first year post-release, tortoises that wander more than 2 km from the core area should be retrieved and returned to the core area. 7. Release of penned tortoises should be gradual and voluntary. Rather than transporting tortoises to an area outside of the pen, we recommend leaving the gates to the enclosure open after a suitably long penning period. Feeding should be continued within the pen during the release period, although the amount of food provided can gradually be decreased. We recommend initiating release period at the onset of the wet season (June) when food is increasingly abundant and tortoises most active. 8. Constant on-site security must be provided by Forest Department staff during the penning phase to ensure that tortoises are not purloined by villagers. After training provided by Wildlife Conservation Society, on-site personnel will conduct pre- and post-release monitoring. 9. A community education campaign should be conducted to explain project goals prior to initiating reintroduction of tortoises at either SSWS or MWS. Education coupled with effective enforcement of existing regulations will be especially critical at SSWS where local villagers have a history of subsistence and commercial exploitation of wildlife. Considerable community outreach to engender conservation values and reinforce existing religious beliefs concerning tortoises has already been conducted in the villages surrounding MWS. The nearubiquitous belief in Nats as guardians of tortoises at MWS provides an excellent foundation for future conservation action in this sanctuary. 10. In recognition of the widespread belief in Nats near MWS, we strongly recommend enlisting the aid of local Buddhist monks to conduct a “donation” ceremony prior to initiating the project. In this ceremony, those tortoises selected for release will be formally “donated” to the monks living in the monastery on Minzon Taung. During the same event, a local shaman will conduct a ceremony to appease the Nats dwelling in the mountain. Local villagers will be invited to participate in the ceremony. 6 Recommendations for assurance colonies Shwe Settaw Wildlife Sanctuary 1. The existing facility should be expanded by a factor of at least 3 to accommodate the increasing population of star tortoises. 2. A secure enclosure with adequate exposure to sunlight should be constructed within the facility for hatchlings. 3. The crumbling bamboo perimeter fences should be replaced with chain-link or wire mesh topped with razor-wire to deter the potential theft of captive animals. 4. Microchips should be implanted in every tortoise housed in the assurance colony. A microchip reader should be supplied to the sanctuary. 5. A pair of tree-calipers is urgently needed to monitor growth of captive tortoises. 6. Separate housing should be provided for other species of turtles currently maintained within star tortoise enclosure. Minzontaung Wildlife Sanctuary 1. It is imperative to immediately relieve over-crowded conditions in the juvenile grow-out enclosures. We strongly recommend that adult tortoises be kept only in the spacious outdoor pens within the walled enclosure. The grow-out pens should be reserved only for hatchlings and juvenile tortoises. Failure to address the over-crowding issue could result in a disease outbreak with the potential to decimate the existing assurance colony. 2. Urgent attention should be given to providing tortoises with a sufficient quantity of proper foodstuffs. Tortoises should be fed once or twice daily, and freshwater should always be available. Water containers and shallow pools should be cleaned immediately after becoming soiled. If an adequate diet is not provided, the loss of a large number of animals is very likely. 3. Two of the three juvenile grow-out enclosures need to be lined with smallmesh wire netting to prevent access by predators, particularly rats. 4. Enhanced security measures to deter thieves are urgently needed. These measures should include rolls of concertina wire to augment existing strands of barbed wire that ring the perimeter wall, construction of an additional guard tower in one corner of the enclosure, and denying cover to potential thieves by clearing thick vegetation away from the perimeter wall. 5. The current water delivery system is inadequate to provide for the large number of tortoises in the assurance colony. The water situation is said to become acute during the dry season. We recommend purchasing a pump to install at the reservoir adjacent to sanctuary headquarters, and constructing an elevated water tank with a gravity-fed delivery system to the pens. 6. A microchip should be implanted in every tortoise housed in the assurance colony to insure proper identification.
Added by: Sarina Wunderlich |