The global pet trade in amphibians: species traits, taxonomic bias, and future directions
The burgeoning global pet trade in vertebrates, including amphibians, has conservation implications for overexploitation of native populations, spread of diseases, and invasions. The majority of amphibian invasions are due to the pet trade pathway and current lists of extra-limital amphibians suggest that future invasions will encompass a broader taxonomic diversity than is known. Given that trade is dynamic, it is essential to move beyond currently traded species and understand which species are likely to be traded in the future and serve as candidates for invasions. In this study, we systematically assess amphibian species in the pet trade, (i) characterising taxonomic bias, (ii) evaluating species-traits as predictors of traded species and trade volume, and (iii) forecasting likely future pets. We collated a global list of 443 traded amphibians and a regional dataset (USA) on trade volume. Species-traits (body size, native range size, clutch size, and breeding type) and conservation status, were considered as predictors of traded species and volume. Six Families contributed disproportionately to the amphibian pet trade; the likelihood for species to be traded was positively associated with body size, range size, and a ‘larval’ breeding type. However, species-traits performed poorly in predicting trade volume, suggesting an overriding effect of socio-economic aspects of the trade. The identified species-traits and taxonomic bias of the trade were then used to predict species likely to be traded as pets in the future. This study formalizes the knowledge on amphibian species that are traded as pets. We found a strong bias for certain Families, along with a preference for large-bodied and widely distributed species with a larval phase. Our results pave way for more trait-based approaches to forecast amphibians entering the trade. Such understanding of the pet trade can help pre-emptively tackle the pathway responsible for most invasions and disease spread in amphibians.
KeywordsAmphibia Invasive species Exotic species Ornamental trade Life-history traits Frog Newt
We would like to thank the USFWS for sharing data on amphibian imports; Martin Schlaepfer, Oliver Stringham, Hollis Dahn, James Baxter-Gilbert and Carla Wagener for valuable inputs to the study. Comments by two anonymous reviewers and the editor, helped improve the manuscript.
NPM and JM conceived the study. NPM collated and analysed the data. NPM and JM wrote the manuscript and approved the final version of the manuscript.
This research was supported by the DST-NRF Centre of Excellence for Invasion Biology (CIB).
Compliance with ethical standards
Conflict of interest
The authors declare no conflict of interest.
No ethical approval was required for this study.
- Environmental Systems Research Institute (ESRI) (2012). Arc-GIS Release 10.6.1. Redlands, CAGoogle Scholar
- Frost, D. R. (2019). Amphibian species of the world: an online reference. Version 6.0. New York, NY: American Museum of Natural History. http://research.amnh.org/herpetology/amphibia/index.html
- Herrel A, van der Meijden A (2014) An analysis of the live reptile and amphibian trade in the USA compared to the global trade in endangered species. Herpetol J 24(2):103–110Google Scholar
- IUCN Red List of Threatened Species (2019). https://www.iucnredlist.org. Accessed 9 Apr 2019.
- Lockwood JL, Welbourne DJ, Romagosa CM, Cassey P, Mandrak NE, Strecker A, Leung B, Stringham OC, Udell B, Episcopio-Sturgeon DJ, Tlusty MF, Sinclair J, Springborn MR, Pienaar EF, Rhyne AL, Keller R (2019) When pets become pests: the role of the exotic pet trade in producing invasive vertebrate animals. Front Ecol Environ. https://doi.org/10.1002/fee.2059 Google Scholar
- Measey J (2017) Where do African clawed frogs come from? An analysis of trade in live Xenopus laevis imported into the USA. Salamandra 53:398–404Google Scholar
- R Core Team (2019) R: a language and environment for statistical computing. R Foundation for Statistical Computing, ViennaGoogle Scholar
- Tapley B, Griffiths RA, Bride I (2011) Dynamics of the trade in reptiles and amphibians within the United Kingdom over a ten-year period. Herpetol J 21:27–34Google Scholar
- Tingley R, Romagosa CM, Kraus F, Bickford D, Phillips BL, Shine R (2010) The frog filter: amphibian introduction bias driven by taxonomy, body size and biogeography. Glob Ecol Biogeogr 19(4):496–503Google Scholar