Applying skin-size limits for management of trade in Asian reptile skins
Daniel J. D. Natusch
A B E , Jessica A. Lyons B , A Department of Biological Sciences, Macquarie University, North Ryde, NSW 2109, Australia.
B EPIC Biodiversity, Frogs Hollow, NSW 2550, Australia.
C Museum Zoologicum Bogoriense, Research Center for Biology, Indonesian Institute of Sciences (LIPI), Gedung Widyasatwaloka, Jalan Raya Jakarta-Bogor km 46 Cibinong, Bogor, West Java, Indonesia.
D Department of Wildlife and National Parks, Peninsular Malaysia, KM10 Jalan Cheras 56100, Kuala Lumpur, Malaysia.
E Corresponding author. Email: d.natusch@epicbiodiversity.com
Wildlife Research 47(1) 89-98 https://doi.org/10.1071/WR19122
Submitted: 18 July 2020 Accepted: 11 October 2019 Published: 30 January 2020
Abstract
Context: Each year, millions of reptile skins are commercially exported from Southeast Asia for exotic leathers. Quotas are commonly used to regulate this trade, but quotas are sometimes exceeded and do little to ensure harvest sustainability.
Aims: To explore the relationship between the size of live pythons and their skins, and to assess whether skin measurements can be used to enforce the application of limits on the size of harvested snakes.
Methods: We measured the body size of three heavily harvested python species (Malayopython reticulatus, Python breitensteini and Python brongersmai) in Indonesia and Malaysia and examined the relationship with skin length, skin width, the size of the ventral scale and its adjacent dorsal scale.
Key results: Measurements of 2261 pythons showed strong relationships between the size of live pythons and measurements made on their skins. Skins can be stretched 30% longer than the body length of snakes from which they came and inter-facility and country differences in stretching technique result in different relationships between the sizes of live snakes and the measurements made on their skins. Male and female Malayopython reticulatus differed in their skin dimensions relative to the size of the live snake, but these differences were minor.
Conclusions: Despite variations in stretching techniques, in functional terms, this variation is minor (maximum 3.5% relative to each mean measurement) and does not limit application of skin sizes for regulating trade within an acceptable level of error. However, differences in the stretched length of Indonesian and Malaysian skins were much greater (5.9% of the mean length of skins), and, thus, each country should apply its own limits and predictive tools.
Implications: The strong relationship between the skin size and the size of the live snake offers great potential for regulating trade by using skin-size limits. Inspection of the size of skins can be used to enforce harvest-size limits and focus harvesting away from sexes and life stages most critical for population persistence. This management tool has numerous advantages over current regulatory practices (quotas) and should be considered for management of trade in Asian reptile skins.
Additional keywords: CITES, hunting, Indonesia, Malaysia, non-detriment, python quota, sustainable use, wildlife trade.
References
Aust, P., Nguyen, T., Natusch, D. J. D., and Alexander, G. (2016). Asian snake farms: conservation curse or sustainable enterprize? Oryx , .| Asian snake farms: conservation curse or sustainable enterprize?Crossref | GoogleScholarGoogle Scholar |
CITES (2017a). ‘Resolution Conference 16.7 (Rev. CoP17). Non-detriment Findings.’ Available at https://www.cites.org/eng/res/16/16-07.php [verified 9 April 2019].
CITES (2017b). ‘Resolution Conference 16.6. (Rev. CoP17). CITES and Livelihoods.’ Available at https://cites.org/sites/default/files/document/E-Res-16-06-R17.pdf [verified 9 April 2019].
CITES (2019). ‘CITES Trade Database.’ Available at http://trade.cites.org/ [verified April 2019].
Copes, P. (1986). A critical review of the individual quota as a device in fisheries management. Land Economics 62, 278–291.
| A critical review of the individual quota as a device in fisheries management.Crossref | GoogleScholarGoogle Scholar |
Dorcas, M. E., and Willson, J. D. (2009). Innovative methods for studies of snake ecology and conservation. In ‘Snakes: Applied Ecology and Conservation’. (Eds S. J. Mullin, and R. A. Seigel.) pp. 5–37. (Cornell University Press: Ithaca, NY, USA.)
Fitzgerald, L. A. (2012). Studying and monitoring exploited species. In ‘Measuring and Monitoring Biological Diversity: Standard Methods for Reptiles’. (Eds R. W. McDiarmid, M. S. Foster, C. Guyer, J. W. Gibbons, and N. Chernoff.) pp. 323–331. (University of California Press: Berkeley, CA, USA.)
Fitzgerald, L. A., Chani, J. M., and Donadio, O. E. (1991). Tupinambis lizards in Argentina: implementing management of a traditionally exploited resource. In ‘Neotropical wildlife: Use and Conservation’. (Eds J. Robinson, and K. Redford.) pp. 303–316. (University of Chicago Press: Chicago, IL, USA.)
Foster, S. J., and Vincent, A. C. J. (2005). Enhancing sustainability of the international trade in seahorses with a single minimum size limit. Conservation Biology 19, 1044–1050.
Groombridge, B., and Luxmoore, R. (1991). Pythons in Southeast Asia. A review of distribution, status and trade in three selected species. Report to CITES Secretariat, Lausanne, Switzerland.
Jenkins, M., and Broad, S. (1994). ‘International Trade in Reptile Skins: a Review and analysis of the Main Consumer Markets 1983–1991.’ (TRAFFIC International: Cambridge, UK.)
Kasterine, A., Arbeid, R., Caillabet, O., and Natusch, D. (2012). ‘The Trade in South-East Asian Python Skins.’ (International Trade Centre: Geneva, Switzerland.)
Kruse, G. H., Byrne, L. C., Funk, F. C., Matulich, S. C., and Zheng, J. (2000). Analysis of minimum size limit for the red king crab fishery in Bristol Bay, Alaska. North American Journal of Fisheries Management 20, 307–319.
| Analysis of minimum size limit for the red king crab fishery in Bristol Bay, Alaska.Crossref | GoogleScholarGoogle Scholar |
Micucci, P. A., and Waller, T. (2007). The management of yellow anacondas (Eunectes notaeus) in Argentina: from historical misuse to resource appreciation. Iguana 14, 161–171.
Mieres, M. M., and Fitzgerald, L. E. (2006). Monitoring and managing the harvest of tegu lizards in Paraguay. The Journal of Wildlife Management 70, 1723–1734.
| Monitoring and managing the harvest of tegu lizards in Paraguay.Crossref | GoogleScholarGoogle Scholar |
Naretto, S., Cardozo, G., Blengini, C. S., and Chiaraviglio, M. (2015). Importance of reproductive biology of a harvest lizard, Tupinambis merianae, for the management of commercial harvesting. Wildlife Research 42, 697–704.
| Importance of reproductive biology of a harvest lizard, Tupinambis merianae, for the management of commercial harvesting.Crossref | GoogleScholarGoogle Scholar |
Natusch, D. J. D., and Lyons, J. A. (2012). Exploited for pets: the harvest and trade of amphibians and reptiles from Indonesian New Guinea. Biodiversity and Conservation 21, 2899–2911.
| Exploited for pets: the harvest and trade of amphibians and reptiles from Indonesian New Guinea.Crossref | GoogleScholarGoogle Scholar |
Natusch, D. J. D., Waller, T., Micucci, P., and Lichtschein, V. (2015). ‘Developing CITES Non-detriment Findings for Snakes.’ Available at https://cites.org/sites/default/files/eng/com/ac/28/E-AC28-14-01_Annex2.pdf [verified 9 April 2019].
Natusch, D. J. D., Lyons, J. A., Mumpuni, Riyanto, A., Khadiejah, S., Mustapha, N., Badiah, and Ratnaningsih, S. (2016a). ‘Sustainable Management of the Trade in Reticulated Python Skins in Indonesia and Malaysia.’ Occasional Paper of the IUCN Species Survival Commission No. 61. (IUCN: Gland, Switzerland.)
Natusch, D. J. D., Lyons, J. A., Mumpuni, , Riyanto, A., and Shine, R. (2016b). Jungle giants: assessing sustainable harvesting in a difficult-to-survey species (Python reticulatus). PLoS One 11, e0158397.
| Jungle giants: assessing sustainable harvesting in a difficult-to-survey species (Python reticulatus).Crossref | GoogleScholarGoogle Scholar |
Natusch, D. J. D., Lyons, J. A., Riyanto, A., Mumpuni, , and Shine, R. (2018). Interspecific divergence in biological attributes of short-tailed pythons (Python breitensteini and P. brongersmai) from Kalimantan and Sumatra. Australian Journal of Zoology 66, 272–278.
| Interspecific divergence in biological attributes of short-tailed pythons (Python breitensteini and P. brongersmai) from Kalimantan and Sumatra.Crossref | GoogleScholarGoogle Scholar |
Natusch, D. J. D., Lyons, J. A., Riyanto, A., Mumpuni, , and Shine, R. (2019a). Harvest impacts on blood pythons in North Sumatra. Journal of Wildlife Management , .
| Harvest impacts on blood pythons in North Sumatra.Crossref | GoogleScholarGoogle Scholar |
Natusch, D. J. D., Lyons, J., Riyanto, A., Mumpuni, , Khadiejah, S., and Shine, R. (2019b). Detailed biological data are informative, but robust trends are needed for informing sustainability of wildlife harvesting: a case study of reptile offtake in Southeast Asia. Biological Conservation 233, 83–92.
| Detailed biological data are informative, but robust trends are needed for informing sustainability of wildlife harvesting: a case study of reptile offtake in Southeast Asia.Crossref | GoogleScholarGoogle Scholar |
Nijman, V., Shepherd, C. R., Mumpuni, , and Saunders, K. L. (2012). Over-exploitation and illegal trade of reptiles in Indonesia. The Herpetological Journal 22, 83–89.
Nossal, K., Khadiejah, S., Mustapha, N., Lettoof, D., Ithnin, H., and Natusch, D. J. D. (2016). ‘People and Trade: the Livelihood Impacts of Python Skin Trade in Peninsular Malaysia.’ (International Trade Centre: Geneva, Switzerland.)
Roe, D., Mulliken, T., Milledge, S., Mremi, J., Mosha, S., and Grieg-Gran, M. (2002). ‘Making a Killing or Making a Living? Wildlife Trade, Trade Controls and Rural Livelihoods. Biodiversity and Livelihoods Issues No. 6.’ (International Institute for Environment and Development: London, UK.)
Shine, R., Ambariyanto, , Harlow, P. S., and Mumpuni, (1999a). Ecological attributes of two commercially-harvested python species in northern Sumatra. Journal of Herpetology 33, 249–257.
| Ecological attributes of two commercially-harvested python species in northern Sumatra.Crossref | GoogleScholarGoogle Scholar |
Shine, R., Ambaryianto, , Harlow, P. S., and Mumpuni, (1999b). Reticulated pythons in Sumatra: biology, harvesting and sustainability. Biological Conservation 87, 349–357.
| Reticulated pythons in Sumatra: biology, harvesting and sustainability.Crossref | GoogleScholarGoogle Scholar |
Siswomartono, D. (1998). Review of the policy and activities of wildlife utilization in Indonesia. Mertensiella 9, 27–31.
Sutherland, W. J. (2001). Sustainable exploitation: a review of principles and methods. Wildlife Biology 7, 131–140.
| Sustainable exploitation: a review of principles and methods.Crossref | GoogleScholarGoogle Scholar |
Webb, G. J., Brien, M., Manolis, C., and Medrano-Bitar, S. (2012). Predicting total lengths of spectacled caiman (Caiman crocodilus) from skin measurements: a tool for managing the skin trade. Herpetological Conservation and Biology 7, 16–26.
World Bank (2019). ‘World Development Indicators.’ (World Bank: Washington DC, USA.) Available at http://povertydata.worldbank.org/poverty/country/IDN [verified April 2019].
