TLN004
TurtleLog:
Online Newsletter of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group
International Union for Conservation of Nature / Species Survival Commission
ISSN: 1947-7635 (online) • iucn-tftsg.org/turtlelog_online_newsletter/
TurtleLog Number 4 • Published 16 September 2009 • doi:10.3854/tln.004.2009
Taxonomic and Morphometric Analysis of a
Trade Confiscation of Turtle Shells from Java, Indonesia
Roger C. Kendrick1 and Gary W.J. Ades1
1Kadoorie Farm and Botanic Garden,
Lam Kam Road, Tai Po, N.T., Hong Kong
[[email protected], [email protected]]
A single large illegal shipment of turtle shells weighing 897 kg and containing approximately 10,000 whole and broken turtle plastra originating from Java, Indonesia, was confiscated in Hong Kong in January 2006 (Figs. 1–2; Anonymous 2006).
The shipment contained three CITES Appendix II listed species: Cuora amboinensis (Southeast Asian Box Turtle), Siebenrockiella crassicollis (Black Marsh Turtle), and Orlitia borneensis (Malaysian Giant Turtle) (Figs. 3–4). Four subspecies of Cuora amboinensis are currently recognized (Schoppe 2009), and based on the point of origin of the shipment, it was assumed that the subspecies involved was C. a. couro from Java and Sumatra.
All shells were turned over by HKSAR Government’s Agriculture, Fisheries and Conservation Department (AFCD) to Kadoorie Farm and Botanic Garden (KFBG) for taxonomic and morphometric analysis.
Figure 1. Cartons of turtle plastra, as delivered by AFCD to KFBG; each carton weighed between 35 and 40 kg for a total weight of 897 kg, January 2006. Photo by R.C. Kendrick.
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Figure 2. Half of all the turtle plastra in the shipment, sorted and boxed for analysis, January 2006. Photo by R.C. Kendrick.
Methods
For complete plastra, three measurements were obtained to the nearest mm: (1) curved plastral length (tape measure, greatest), (2) curved plastral width (tape measure, midpoint), and (3) straight plastral width (ruler, greatest).
Also recorded were the sex (male, female, or unknown), determined by the degree of concavity or convexity of the plastron, with males being concave, and the relative age of the animal, i.e. juvenile (small, very “fresh” plastrons), subadult, or adult; based upon the degree of wear and length of the plastron, with smaller worn plastrons classified as adult, but smaller than median and much less worn plastrons classified as subadult). Determination of sex in a few cases was not clear; a small number of plastrons were classified as “undetermined” since they did not show sufficiently strong concavity or convexity to be clearly male or female.
Figure 3. Boxes of turtle plastra of two of the species identified in the shipment: (top) Cuora amboinensis, (bottom) Siebenrockiella crassicollis. Photos by R.C. Kendrick.
Figure 4. Turtle plastra of the three species identified in the shipment: (top) Cuora amboinensis, (middle) Siebenrockiella crassicollis, (bottom) Orlitia borneensis. Photos by R.C. Kendrick.
Results
The size of the confiscated shipment was approximately 10,000 turtle plastra, weighing ca. 897 kg in total. Many plastra were broken and were not measured; 6951 whole plastra were measured, of which there were 4588 Cuora amboinensis (66.0%), 2253 Siebenrockiella crassicollis (32.4%), 33 Orlitia borneensis (0.5%), and 77 not identified to species (1.1%).
The breakdown of each species according to age and sex is given in Tables 1 and 2. Most plastra (ca. 89% for C. amboinensis, ca. 75% for S. crassicollis, and ca. 94% for O. borneensis) appear to have come from adult turtles, though the O. borneensis specimens were substantially smaller than the maximum size of 800 mm length given by Ernst et al. (1997), thus it may be possible that some of the O. borneensis plastrons classified as adult were from subadult turtles. There were slightly more females than males for C. amboinensis and S. crassicollis. Three-quarters of the O. borneensis were females.
For the two species with many plastra (C. amboinensis and S. crassicollis), overall distribution of plastron lengths by sex were plotted in 10 mm class ranges (Figs. 5–6).
For C. amboinensis (Fig. 5) the median class range was 161–170 mm, both overall and for males and females; the largest specimens were females, up to 220 mm in length. Maximum adult length is in the region of 220–250 mm (Ernst et al. 1997, Bonin et al. 2006), thus the range of C. amboinensis plastron lengths observed here probably covers class sizes from juvenile to fully mature adult individuals.
Figure 5. Size distribution of Cuora amboinensis turtle plastra classed by sex.
For S. crassicollis (Fig. 6), the median class range was 141–150 mm, both overall and for males and females; the largest specimens were females, up to 200 mm in length. The overall adult length is in the region of 200 mm (Bonin et al. 2006), rarely up to 340 mm (Jenkins 1995), thus the range of S. crassicollis plastron lengths observed here probably covers class sizes from juvenile to fully mature adult individuals.
Figure 6. Size distribution of Siebenrockiella crassicollis turtle plastra classed by sex.
For O. borneensis, the median class range was 361–370 mm overall and for females, but for males the median class range was 421–430 mm and the largest plastron was a male, just under 500 mm in length. It is noted that for O. borneensis, adults grow up to approximately 800 mm in total length (Ernst et al. 1997). From this small sample, it is clear that all the specimens were not fully grown individuals and probably represented young adults.
The morphometric observations indicate that the largest proportion of turtles for all three species being collected at this time (late 2005) were relatively young adults, with mature and old adults forming only a small part of the populations.
Removal of plastra appears to have been undertaken roughly and without automated tools, as cutting was jagged, inconsistent in terms of the actual cutting location, and in some cases dried body tissue was still attached.
The presence amongst the plastra upon arrival at KFBG of hundreds of pupae of a meal moth species (Pyralis manihotalis), which specializes in animal detritus, indicated that there had been significant amounts of body tissue remaining during shipment. It is not known if the moth pupae were derived from eggs laid in Hong Kong while the shipment was being held by AFCD, or from the original location (Java), though the latter is more likely, as this tropical moth species is not normally found in sufficient abundance in Hong Kong to have been able to produce such a large infestation, especially during the winter in Hong Kong, when P. manihotalis is normally in a prolonged hibernation phase.
Discussion
The distribution patterns for both C. amboinensis and S. crassicollis plastron lengths (Figs. 5 and 6) were skewed normal distributions, with few large adults. This suggests that at the time of capture (probably late 2005), the wild populations still contained representatives of all age classes. The distribution of O. borneensis specimens (from a much smaller sample) indicated there were no large adults in the captured sample.
Based on the knowledge that most species of Southeast Asian freshwater turtles are under intense collecting pressure for the food market in China (van Dijk et al. 2000, Shi et al. 2009), it is unlikely that the three species included in this shipment were being harvested from the wild in a sustainable manner. Removal of large numbers of subadults and young adults from wild populations have a detrimental impact upon the future breeding stock of the species. Under the current practice, we agree with observations reported by Cheung and Dudgeon (2006) and Chen et al. (2009), that the collection and trade of wild populations of these species is unsustainable.
This confiscation represents just a small part of the overall illegal trade in live animals, meat, and shells of these and other turtle species in Asia, and is clearly another indication of the unsustainable trade that is affecting turtles across the region (van Dijk et al. 2000, Cheung and Dudgeon 2006, Hudson 2009, Philippen 2009, Chen et al. 2009).
Acknowledgments. — We are grateful to the following volunteers for morphometric measurements and data computerization: Sharon Chan, Anne Chow, Dorothy Choy, Vicky Chu, May Chuen, Chris Fong, Shirley Kot, Mandy Kwan, Candy Lam, Veronica Lau, Lun Kwok Hei, Colleen Leung, Cassandra Nichols, Elizabeth On, Michelle Poon, Karmen Tam, Karol Tang, Horace Tang, Jenny Siu, Pinky Wan, and Kevin Yiu. KFBG also thanks the AFCD for their assistance with this study.
Literature Cited
Anonymous. 2006. Seizures and prosecutions. TRAFFIC Bulletin 21(1): 35-40.
Bonin, F., Devaux, B. and Dupré, A. 2006. Turtles of the World. A and C Black Publishers, London. 416 pp.
Chen, T.H., Chang, H.C. and Lue, K.Y. 2009. Unregulated trade in turtle shells for Chinese Traditional Medicine in East and Southeast Asia: the case of Taiwan. Chelonian Conservation and Biology 8(1):11-18.
Cheung, S.M. and Dudgeon, D. 2006. Quantifying the Asian turtle crisis: market surveys in southern China, 2000-2003. Aquatic Conservation: Marine and Freshwater Ecosystems 16(7): 751-770.
Ernst, C.H., Altenburg, R.G.M. and Barbour, R.W. 1997. Turtles of the World. ETI Information Systems Ltd, Netherlands.
Hudson, R. 2009. News from the Field: Thailand, Cambodia, Malaysia and Singapore. Turtle Survival Alliance Newsletter, 24 February 2009: 1-4.
Jenkins, M.D. 1995. Tortoises and Freshwater Turtles: The Trade in Southeast Asia. TRAFFIC International, Cambridge, UK.
Philippen, H-D. 2009. Malayan Giant Turtle, Orlitia borneensis hunting still hot in Borneo. //www.asianturtlenetwork.org/library/ATCN_news/2008_articles/FL_Orlitia_story_Borneo_March_18_2009.html
Schoppe, S. 2009. Status, trade dynamics and management of the Southeast Asian Box Turtle Cuora amboinensis in Indonesia. TRAFFIC Southeast Asia, Petaling Jaya, Selangor, Malaysia, 90 pp.
Shi, H.T., Parham, J.F., Buley, K., Lau, M.W.N., O’Connell, D., and Fong, J. 2009. An action plan for turtle conservation in China and a brief introduction on our conservation and research efforts of turtles in China. Presentation at the 23rd Annual Meeting and International Congress for Conservation Biology.
van Dijk, P.P., Stuart, B.L., and Rhodin, A.G.J. (Eds.) 2000. Asian Turtle Trade: Proceedings of a Workshop on Conservation and Trade of Freshwater Turtles and Tortoises in Asia. Chelonian Research Monographs No. 2, 164 pp.
Citation Format for this Publication:
Kendrick, R.C. and Ades, G.W.J. 2009. Taxonomic and morphometric analysis of a trade confiscation of turtle shells from Java, Indonesia. TurtleLog No. 4, doi:10.3854/tln.004.2009, //iucn-tftsg.org/turtlelog_online_newsletter/tln004/.