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The illegal pet trade is driving Madagascar's ploughshare tortoise to extinction

  • Angelo R. Mandimbihasina (a1), Lance G. Woolaver (a1), Lianne E. Concannon (a2), E. J. Milner-Gulland (a3), Richard E. Lewis (a1), Andrew M.R. Terry (a2), Niaraha Filazaha (a1), Lydia L. Rabetafika (a4) and Richard P. Young (a2)...


The illegal wildlife trade is driving declines in populations of a number of large, charismatic animal species but also many lesser known and restricted-range species, some of which are now facing extinction as a result. The ploughshare tortoise Astrochelys yniphora, endemic to the Baly Bay National Park of north-western Madagascar, is affected by poaching for the international illegal pet trade. To quantify this, we estimated population trends during 2006–2015, using distance sampling surveys along line transects, and recorded national and international confiscations of trafficked tortoises for 2002–2016. The results suggest the ploughshare tortoise population declined > 50% during this period, to c. 500 adults and subadults in 2014–2015. Prior to 2006 very few tortoises were seized either in Madagascar or internationally but confiscations increased sharply from 2010. Since 2015 poaching has intensified, with field reports suggesting that two of the four subpopulations are extinct, leaving an unknown but almost certainly perilously low number of adult tortoises in the wild. This study has produced the first reliable population estimate of the ploughshare tortoise and shows that the species has declined rapidly because of poaching for the international pet trade. There is an urgent need for increased action both in Madagascar and along international trade routes if the extinction of the ploughshare tortoise in the wild is to be prevented.


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Also at: Department of Animal Biology, University of Antananarivo, Antananarivo, Madagascar



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Andrianandrasana, H. (2017) Testing the effectiveness of community-based conservation in conserving biodiversity, protecting ecosystem services, and improving human well-being in Madagascar. DPhil thesis, University of Oxford, Oxford, UK.
Avery, J. (2016) Anti-poaching pooches. Man's best friend plays a vital role in the war against poaching. Africa Geographic Magazine, 125. Http:// [accessed 6 June 2017].
Bennett, E.L. (2011) Another inconvenient truth: the failure of enforcement systems to save charismatic species. Oryx, 45, 476479.
Biggs, D., Courchamp, F., Martin, R. & Possingham, H.P. (2013) Legal trade of Africa's rhino horns. Science, 339, 10381039.
Buckland, S.T., Anderson, D.R., Burnham, K.P., Laake, J.L., Borchers, D.L. & Thomas, L. (2001) Introduction to Distance Sampling: Estimating Abundance of Biological Populations. Oxford University Press, Oxford, UK.
Challender, D.W.S. & MacMillan, D.C. (2014) Poaching is more than an enforcement problem. Conservation Letters, 7, 484494.
Cheung, S.N. & Dudgeon, D. (2006) Quantifying the Asian turtle crisis: market surveys in southern China, 2000–2003. Aquatic Conservation: Marine and Freshwater Ecosystems, 16, 751770.
CITES (2017) Convention on International Trade in Endangered Species of Wild Fauna and Flora. Appendices I, II and III. Http:// [accessed 18 March 2017].
Curl, D.A. (1986) The rarest tortoise on earth. Oryx, 20, 3539.
Curl, D.A., Scoones, I.C., Guy, M.K. & Rakotoarisoa, G. (1985) The Madagascar tortoise Geochelone yniphora: current status and distribution. Biological Conservation, 34, 3554.
D'Cruze, N. & Macdonald, D.W. (2016) A review of global trends in CITES live wildlife confiscations. Nature Conservation, 15, 4763.
Durbin, J., Rajafetra, V., Reid, D. & Razandrizanakanirina, D. (1996) Local people and project Angonoka – Conservation of the ploughshare tortoise in north-western Madagascar. Oryx, 30, 113120.
Gibbons, P. (2015) Ploughshare Tortoise Trafficking Update. Turtle Conservancy, Ojai, USA. Https:// [accessed 18 March 2016].
Gore, M.L., Ratsimbazafy, J. & Lute, M.L. (2013) Rethinking corruption in conservation crime: insights from Madagascar. Conservation Letters, 6, 430438.
Hall, R.J., Milner-Gulland, E.J. & Courchamp, F. (2008) Endangering the endangered: the effect of perceived rarity on species extinction. Conservation Letters, 1, 7581.
Hinsley, A., Lee, T.E., Harrison, J.R. & Roberts, D.L. (2016) Estimating the extent and structure of trade in horticultural orchids via social media. Conservation Biology, 30, 10381047.
Horne, B.D., Poole, C.M. & Walde, A.D. (2012) Conservation of Asian tortoises and freshwater turtles: setting priorities for the next ten years. Recommendations and Conclusions from the Workshop in Singapore, February 21–24, 2011. Wildlife Conservation Society, Singapore.
Jenkins, M.D. (1995) Tortoises and Freshwater Turtles: The Trade in Southeast Asia. TRAFFIC International, Cambridge, UK.
Juvik, J.O., Andrianarivo, A.J. & Blanc, C.P. (1981) The ecology and status of Geochelone yniphora: A critically endangered tortoise in northwestern Madagascar. Biological Conservation, 19, 297316.
Juvik, J.O. & Blanc, C.P. (1974) The Angonoka of Cape Sada. Animals, 16, 148153.
Kiester, A.R., Mandimbihasina, A.R., Lewis, R.E., Goode, E.V., Juvik, J.O., Young, R. & Blanck, T. (2013) Conservation of the Angonoka (Ploughshare tortoise) Astrochelys yniphora. Chelonian Research Monographs, 6, 162170.
Lawson, K. & Vines, A. (2014) Global Impact of the IWT – The Costs of Crime, Insecurity and Institutional Erosion. Chatham House, London, UK.
Leuteritz, T. & Pedrono, M. (Madagascar Tortoise and Freshwater Turtle Red List Workshop) (2008) Astrochelys yniphora. The IUCN Red List of Threatened Species 2008. Http://
Leuteritz, T. & Rioux Paquette, S. (Madagascar Tortoise and Freshwater Turtle Red List Workshop) (2008) Astrochelys radiata. The IUCN Red List of Threatened Species. Http://
Leuteritz, T. & Walker, R. (2014) Pyxis arachnoides. The IUCN Red List of Threatened Species. Http://
Leuteritz, T., Randriamahazo, H. & Lewis, R. (Madagascar Tortoise and Freshwater Turtle Red List Workshop) (2008) Pyxis planicauda. The IUCN Red List of Threatened Species. Http://
Leuteritz, T.E.J., Lamb, T. & Limberaza, J.C. (2005). Distribution, status, and conservation of radiated tortoises (Geochelone radiata) in Madagascar. Biological Conservation, 124, 451461.
Lyons, J.A. & Natusch, J.D. (2013) Effects of consumer preferences for rarity on the harvest of wild populations within a species. Ecological Economics, 93, 278283.
Mandimbihasina, A. & Woolaver, L. (2014) The ploughshare tortoise Astrochelys yniphora. In Western Indian Ocean Tortoises Ecology: Diversity, Evolution, Conservation, Paleontology (ed. Gerlach, J.), pp. 277296. Siri Scientific Press, Manchester, UK.
Moreto, W.D. & Lemieux, A.M. (2015) Poaching in Uganda: perspectives of law enforcement rangers. Deviant Behavior, 36, 853873.
Morgan, J., & Chng, S. (2017). Rising internet-based trade in the Critically Endangered ploughshare tortoise Astrochelys yniphora in Indonesia highlights need for improved enforcement of CITES. Oryx,
Natusch, J.D. & Lyons, J.A. (2012) Exploited for pets: the harvest and trade of amphibians and reptiles from Indonesian New Guinea. Biodiversity and Conservation, 21, 28992911.
Nijman, V. & Shepherd, C.R. (2007) Trade in non-native, CITES-listed, wildlife in Asia, as exemplified by the trade in freshwater turtles and tortoises (Chelonidae) in Thailand. Contributions to Zoology, 76, 207211.
Nijman, V. & Shepherd, C.R. (2015) Analysis of a decade of trade of tortoises and freshwater turtles in Bangkok, Thailand. Biodiversity and Conservation, 24, 309318.
Nijman, V., Shepherd, C.R., Mumpuni, , Saunders, K.L. (2012). Over-exploitation and illegal trade of reptiles in Indonesia. Herpetological Journal, 22, 8389.
Obbard, M.E., Stapleton, S., Middel, K.R., Thibault, I., Brodeur, V. & Jutras, C. (2015) Estimating the abundance of the Southern Hudson Bay polar bear subpopulation with aerial surveys. Polar Biology, 38, 17131725.
O'Brien, S., et al. (2003) Decline of the Madagascar radiated tortoise Geochelone radiata due to overexploitation. Oryx, 37, 338343.
O'Donoghue, P. & Rutz, C. (2015) Real-time anti-poaching tags could help prevent imminent species extinctions. Journal of Applied Ecology, 53, 510.
Olmedo, A., Sharif, V. & Milner-Gulland, E.J. (2017) Evaluating the design of behaviour change interventions: A case study of rhino horn in Viet Nam. Conservation Letters, 11, 19.
Pedrono, M. (2000) Gestion interactive entre les populations sauvages et captives: Stratégie de conservation de la tortue Astrochelys yniphora à Madagascar. PhD thesis, Université Pierre et Marie Curie, Paris, France.
Pedrono, M. (2008) The Tortoises and Turtles of Madagascar. Natural History Publications, Borneo.
Raghavan, R., Luz, S., Shepherd, C.R., Lewis, R., Gibbons, P. & Goode, E. (2015) A case study of the ploughshare tortoise and the role zoos can play in conservation. TRAFFIC Bulletin, 27, 7984.
Randriamalala, H. & Liu, Z. (2010) Rosewood of Madagascar: between democracy and conservation. Madagascar Conservation & Development, 5, 1122.
Rosen, G.E. & Smith, K.F. (2010) Summarizing the evidence on the international trade in illegal wildlife. EcoHealth, 7, 2432.
Smith, L.L., Bourou, R., Mahatoly, J. & Sibo, C. (1999a) Home range and microhabitat use in the Angonoka (Geochelone yniphora) in Madagascar. Chelonian Conservation and Biology, 3, 393400.
Smith, L.L., Linehan, J.M., Stober, J.M., Elliott, M.J. & Jensen, J.B. (2009) An evaluation of distance sampling for large-scale gopher tortoise surveys in Georgia, USA. Applied Herpetology, 6, 355368.
Smith, L.L., Reid, D., Bourou, R., Mahatoly, J. & Sibo, C. (1999b) Status and distribution of the angonoka tortoise (Geochelone yniphora) of western Madagascar. Biological Conservation, 91, 2333.
Swann, D.E., Averill-Murray, R.C. & Schwalbe, C.R. (2002) Distance sampling for Sonoran desert tortoises. Journal of Wildlife Management, 66, 969975.
Thomas, L., Buckland, S.T., Rexstad, E.A., Laake, J.L., Strindberg, S., Hedley, S.L. et al. (2010) Distance software: design and analysis of distance sampling surveys for estimating population size. Journal of Applied Ecology, 47, 514.
TRAFFIC (2014) Seizures and prosecutions. TRAFFIC Bulletin, 16 (3) (March 1997)–26 (2) (October 2014).
TRAFFIC (2016) TRAFFIC's engagement on African rhinoceros conservation and the global trade in rhinoceros horn. Http:// [accessed 24 November 2016].
Underwood, F.M., Burn, R.W. & Milliken, T. (2013) Dissecting the illegal ivory trade: an analysis of ivory seizures data. PLoS ONE, 8, e76539.
Vaillant, L. & Grandidier, G. (1910) Histoire Naturelle des Reptiles, Première Partie: Crocodiles et Tortues. In Histoire Physique Naturelle et Politique de Madagascar (eds Grandidier, A. & Grandidier, G.), vol. 17, pp. 186. Imprimerie nationale, Paris, France.
Veríssimo, D., Challender, D.W.S. & Nijman, V. (2012) Wildlife trade in Asia: start with the consumer. Asian Journal of Conservation Biology, 2, 4950.
Walker, R.C. & Rafeliarisoa, T.H. (2012) Status of the relict population of the Critically Endangered Madagascar spider tortoise Pyxis arachnoides. Oryx, 46, 457463.
Walker, R.C.J. (2012) The internet based trade in Madagascar's critically endangered tortoise species: A preliminary study identifying the conservation threats. Testudo, 7, 313.
Wallis, D. (2009). Evaluating the short-term success of a reintroduction of the Critically Endangered ploughshare tortoise, Astrochelys yniphora. MSc thesis, Imperial College London, London, UK.
Wyler, L.S. & Sheikh, P.A. (2013) International Illegal Trade in Wildlife: Threats and U.S. Policy. CRS report for Congress, Damascus, USA.
Young, R.P., Volahy, A.T., Bourou, R., Lewis, R., Durbin, J. & Fa, J.E. (2008) Estimating the population of the Endangered flat-tailed tortoise Pyxis planicauda in the deciduous, dry forest of western Madagascar: a monitoring baseline. Oryx, 42, 252258.
Zhou, Z. & Jiang, Z. (2004) International trade status and crisis for snake species in China. Conservation Biology, 18, 13861394.
Zylstra, E.R., Steidl, R.J. & Swann, D.E. (2010) Evaluating survey methods for monitoring a rare vertebrate, the sonoran desert tortoise. Journal of Wildlife Management, 74, 13111318.
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