Title
Surveys of the Siamese Crocodile Crocodylus siamensis in Savannakhet Province, Lao PDR 6 May – 4 June 2008 Phase 1 Field Trip Report
Author(s)
Jack H. Cox, Jr. and Chanthone Phothitay
Published
2008
Abstract
The Siamese Crocodile Crocodylus siamensis is listed by the International Union for Conservation of Nature (IUCN) as Critically Endangered and is one of the world’s most threatened crocodilians. The species has vanished from nearly all of its historical range in Southeast Asia. Highly fragmented, very small populations persist at a few sites in Cambodia (Daltry et al. 2003, B. Simpson, in litt., 14 June 2008; J. Thorbjarnarson, in litt., 11 July 2008) and Lao PDR (Bezuijen et al. 2006), and possibly in Vietnam, Thailand and Indonesia.
Lao PDR evidently harbors the largest number of wild Siamese Crocodiles. In 2005 small populations were reported in four southern provinces, of which Savannakhet and Attapeu were assessed as more important. Surveys in Savannakhet Province found two sites inhabited by the Siamese Crocodile: Kout Mark Peo oxbow in Champhone District (Bezuijen et al., 2006) and Beung Bon Thong in Xaibouly District (Phothitay and Somphanith 2003).
In response to the urgent need to determine the current status of the species in Savannakhet Province and develop a recovery initiative, OZ Minerals Ltd. provided funding and logistical support through the Wildlife Conservation Society (WCS) program in Lao PDR for population and habitat surveys in the Xe Champhone and Xe Banghiang river systems in May and early June 2008. These Phase 1 activities are part of an envisaged multi-phase program to develop site-specific Management Plans and pilot projects that will enable local communities to lead and substantially benefit from recovery and management of the crocodile resource, and by extension, strengthen the conservation of local wetlands and aquatic biodiversity.
Phase 1 surveys confirmed that the Siamese Crocodile persists in Kout Mark Peo (adult trails, adult and juvenile dung, and an unfinished nest observed), and inhabits at least three other oxbows of the Xe Champhone system: Nong Maehang (adult shined at night), Kout Kaen (locality record for a measured juvenile), and Kout Xelat Kadan (yearling shined at night). Two complete nests were found at a fifth site: Kout Kouang-Kout Koke in Xonbouly District. Each contained infertile eggs. No evidence of hatchlings or small crocodiles was provided by local user groups. Kout Koke is particularly intact and a large trail in dense floating mats indicated the presence of at least one adult crocodile. Existence of a breeding population is advantageous because eggs typically subject to high mortality in the wild can be salvaged, hatched in a controlled environment, and released as reared juveniles to ‘head start’ recovery of local populations.
A visit to the Lao Zoo on 26 April 2008 found ca. 1,000 crocodiles said to originate from Cambodia and many of which showed typical hybrid characters. A group of seven adults were said to have been received in 1993 as young juveniles from Phin District, and are maintained in an isolated enclosure. These crocodiles exhibit non-hybrid morphological characters that are more consistent with the Siamese Crocodile. DNA analyses are needed to confirm the genetic homogeneity of the Phin District crocodiles and incidence of hybridization in other individuals.
Follow-up surveys are needed to adequately assess all five sites and peripheral areas. Beung Bon Thong and proximate wetlands have not yet been surveyed due to time constraints. Other areas in the Xe Champhone and Xe Xangxoy were identified from satellite imagery as having suitable or recoverable crocodile habitat and therefore also merit assessment. None of the six sites or other areas is within a National Protected Area, underscoring the need for development of a community-oriented approach and community-beneficial management to ensure the long-term maintenance of crocodile populations.
Local communities are heavily and increasingly dependent on most of the five sites in the dry season for fishing and irrigation of second crop paddy fields. Peripheral vegetation is mostly intact, but fields adjoin parts of some sites, adjacent wetlands are being gradually converted to fields, and hunter-gatherer activities also disturb crocodiles and habitat. Local people are generally afraid of crocodiles but tolerate them, and at most sites respect them as spiritual entities. Educating people about the shy and retiring nature of the Siamese Crocodile and lack of any records of attack on humans can dispel the prevailing myth of crocodiles as highly dangerous creatures. This will bolster local support for population and habitat recovery and a sense of pride in this unique animal.
Conservation incentives may also be created by development of a community-based alternative fisheries program as planned by the World Wildlife Fund in Lao PDR (ComFish), an exchange initiative that provides pumping systems so that rivers rather than oxbows are sourced for irrigation water, ecotourism and other promising ventures as locally determined and incorporated into holistic and site-specific Management Plans.
Phase 1 results indicate that design and implementation of a community-based initiative are feasible to safeguard some of the last refuges of the Siamese Crocodile in Lao PDR, eventually replenish and link populations in key areas, and in the process conserve the biodiversity of critical wetlands in Savannakhet Province. Such an initiative takes on global importance and greater urgency considering that Lao PDR apparently possesses the largest remaining metapopulation(s?) of the Siamese Crocodile among all range states.
Full Citation
Cox, Jr., J.H. and C. Phothitay (2008). Surveys of the Siamese Crocodile Crocodylus siamensis in Savannakhet Province, Lao PDR 6 May – 4 June 2008 Phase 1 Field Trip Report. Vientiane, Lao PDR: OZ Minerals Ltd. and Wildlife Conservation Society, 1-40.
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