Biodiversity and Conservation

, Volume 23, Issue 6, pp 1541–1550 | Cite as

Bayesian occupancy monitoring for Annamite endemic biodiversity in central Vietnam

  • Thomas N. E. Gray
  • Hoa Anh Nguyen Quang
  • Thien Nguyen Van
Original Paper


Given the crisis facing South-east Asian biodiversity evidence led conservation, including assessing the impact of innovative protected area management models, is urgently needed. Bayesian statistics provide an intuitive way to interpret biodiversity monitoring data but are largely unused, or poorly understood, by field biologists and protected area managers. We built Bayesian occupancy models for two threatened endemics of the Annamite mountains: northern yellow-cheeked gibbon Nomascus (gabriellae) annamensis and crested argus Rheinardia ocellata ocellata based on auditory surveys in three protected areas in central Vietnam. Occupancy of 2 × 2-km grid cells across the landscape was 0.76 ± SE 0.03 for northern yellow-cheeked gibbon and 0.68 ± SE 0.05 for crested argus. Models predicted higher probability of gibbon occurrence at lower elevations and higher probability of crested argus presence with increasing dense forest cover. Bayesian modeling is a useful tool for assessing the effectiveness of conservation interventions and for measuring progress against conservation goals. The wider application of Bayesian statistics in conservation monitoring should allow more intuitive and user-friendly representation of sampling uncertainty, including visual representation of probability distributions and more rigorous testing for changes in the status of conservation targets.


Conservation evidence Galliforme Gibbon Indochina Occupancy Protected area management 



This work forms part of the CarBi project of WWF Greater Mekong largely funded by KfW Bankengruppe and WWF Germany. For permission to work in the study landscape we thank the Thua Thien Hue and Quang Nam Provincial People’s Committee and the management board of Hue and Quang Nam Saola Reserves and Bach Ma National Park. Mike Meredith provided statistical advice and an anonymous reviewer improved the quality of the manuscript. Michael Dine, David Zeller, Thinh Van Ngoc, Fanie Bekker, Anh Le Thuy and Hung Luong Viet provided logistical assistance and support.


  1. Baltzer M, Dao NT, Shore RG (2001) Towards a vision of biodiversity conservation in the forests for the lower Mekong ecoregion complex. WWF Indochina, HanoiGoogle Scholar
  2. BirdLife International (2001) Threatened birds of Asia: the BirdLife International red data book. BirdLife International, CambridgeGoogle Scholar
  3. Brickle NW, Duckworth JW, Tordoff AW, Poole CM, Timmins R, McGowan PJK (2008) The status and conservation of Galliformes in Cambodia, Laos and Vietnam. Biodivers Conserv 17:1393–1427CrossRefGoogle Scholar
  4. Brook S, van Coeverden de Groot C, Scott P, Boag B, Long R, Ley E, Reischer GH, Williams AC, Mahood SP, Hien TM, Polet G, Cox N, Hai BT (2012) Integrated and novel survey methods for rhinoceros populations confirm the extinction of Rhinoceros sondaicus annamiticus from Vietnam. Biol Conserv 155:59–67CrossRefGoogle Scholar
  5. Doniol-Valcroze T, Gosselin JF, Hammill MO (2013) Population modeling and harvest advice under the precautionary approach for eastern Hudson Bay beluga (Delphinapterus leucas). DFO Can Sci Advis Sec Res Doc 2012:168Google Scholar
  6. Drury R (2011) Hungry for success: urban consumer demand for wild animal products in Vietnam. Conserv Soc 9:247–257CrossRefGoogle Scholar
  7. Duckworth JW (2008) Preliminary gibbon status review for Lao PDR 2008. Fauna & Flora International Indochina Programme, VientianeGoogle Scholar
  8. Duckworth JW, Batters G, Belant JL et al (2012) Why South-east Asia should be the world’s priority for averting imminent species extinctions, and a call to join a developing cross-institutional programme to tackle this urgent issue. Surv Perspect Integr Environ Soc 5:77–95.
  9. Efford MG, Dawson DK (2012) Occupancy in continuous habitat. Ecosphere, 3, article 32Google Scholar
  10. Gelman A, Hill J (2006) Data analysis using regression and multilevel/hierarchical models. Cambridge University Press, New YorkCrossRefGoogle Scholar
  11. Gray TNE (2012) Studying large mammals with imperfect detection: status and habitat preferences of wild cattle and large carnivores in eastern Cambodia. Biotropica 44:531–536CrossRefGoogle Scholar
  12. Gray TNE, Phan C, Long B (2010) Modelling species distribution at multiple spatial scales: gibbon habitat preferences in a fragmented landscape. Anim Conserv 13:324–332CrossRefGoogle Scholar
  13. Koh LP, Sodhi NS (2010) Conserving Southeast Asia’s imperiled biodiversity: scientific, management, and policy challenges. Biodvers Conserv 19:913–917CrossRefGoogle Scholar
  14. Laurance WF (2007) Forest destruction in tropical Asia. Curr Sci 93:11Google Scholar
  15. Lim NL, Giam X, Byrnes G, Clements GR (2013) Occurrence of the Sunda colugo (Galeopterus variegatus) in the tropical forests of Singapore: a Bayesian approach. Mamm Biol 78:63–67Google Scholar
  16. MacKenzie D, Nichols JD, Lachman GB, Droege S, Royle JA, Langtimm CA (2002) Estimating site occupancy when detection probabilities are less than one. Ecology 83:2248–2255CrossRefGoogle Scholar
  17. MacKenzie DI, Nichols JD, Royle JA, Pollock KH, Bailey LL, Hines JE (2006) Occupancy estimation and modeling: inferring patterns and dynamics of species occurrence. Elsevier, San DiegoGoogle Scholar
  18. McCarthy MA (2007) Bayesian methods for ecology. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  19. Nijman V (2010) An overview of international wildlife trade from Southeast Asia. Biodvers Conserv 19:1101–1114CrossRefGoogle Scholar
  20. O’Kelly HJ, Evans TDE, Stoke EJ, Clements TJ, An D, Gately M, Nut M, Pollard EHB, Men S, Walston J (2012) Identify conservation successes, failures and future opportunities; assessing recovery potential of wild ungulates and tiger in eastern Cambodia. PLoS ONE 7:e40482PubMedCentralPubMedCrossRefGoogle Scholar
  21. Plummer M (2009) JAGS Version 1.0.3 manual.
  22. Pullin AS, Knight TM (2009) Doing more good than harm—building an evidence-base for conservation and environmental management. Biol Conserv 142:931–934CrossRefGoogle Scholar
  23. Pullin AS, Sutherland W, Gardner TA, Kapos V, Fa JE (2013) Conservation priorities: identifying need, taking action and evaluating success. In: MacDonald D, Willis K (eds) Key topics in conservation. Oxford University Press, OxfordGoogle Scholar
  24. Robbins CS, Bystrak D, Geissler PH (1986) The breeding bird survey: its first fifteen years, 1965–1979. Fish and Wildlife Service, Resource Publication, Washington, DCGoogle Scholar
  25. Saltz D (2011) Statistical inference and decision making in conservation biology. Isr J Ecol Evol 57:309–317CrossRefGoogle Scholar
  26. Schipper J, Chanson JS, Chiozza F et al (2008) The status of the world’s land and marine mammals: diversity, threat and knowledge. Science 322:225–230PubMedCrossRefGoogle Scholar
  27. Segan DB, Bottrill MC, Baxter PW, Possingham HP (2010) Using conservation evidence to guide management. Conserv Biol 25:200–202PubMedCrossRefGoogle Scholar
  28. Sodhi NS, Lee TM, Koh LP, Brook BW (2009) A meta-analysis of the impact of anthropogenic forest disturbance on Southeast Asia’s biotas. Biotropica 41:103–109CrossRefGoogle Scholar
  29. Spiegelhalter DJ, Best NG, Carlin BP, van der Linde A (2002) Bayesian measures of model complexity and fit. J Roy Stat Soc B 64:583–639CrossRefGoogle Scholar
  30. Stanley SA, Hackman R, Ferrand F (2013) REDD feasibility study for Xe Sap NPA and Hue and Quang Nam Saola Reserves, Lao PDR and Vietnam, Forest Carbon and WWF Laos, VientianeGoogle Scholar
  31. Stone R (2006) The saola’s last stand. Science 314:1380–1383PubMedCrossRefGoogle Scholar
  32. Wade PR (2000) Bayesian methods in conservation biology. Conserv Biol 14:1308–1316CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2014

Authors and Affiliations

  • Thomas N. E. Gray
    • 1
    • 4
  • Hoa Anh Nguyen Quang
    • 2
  • Thien Nguyen Van
    • 2
    • 3
  1. 1.WWF Greater MekongVientianeLao PDR
  2. 2.WWF VietnamHue CityVietnam
  3. 3.Department of Agriculture and ForestryHue UniversityHue CityVietnam
  4. 4.Phnom PenhCambodia

Personalised recommendations