Potterheads would remember Trevor, the pet toad of Neville Longbottom and how he made a getaway. Pet frogs and salamanders are not just confined to books and movies but are part of a rampant global trade, finds a new study. Just like Trevor’s escape, accidental escapes or even release of these creatures into the wild is causing a rise in invasive species, adds the paper.
The study found that nearly 450 species of amphibians are traded globally. The two-member team from Stellenbosch University, South Africa tried to figure out what were the special traits that made these species preferable, how to tackle the entry of invasive species and also spread of diseases from them. Trade of pet amphibians has grown rapidly in the last few decades. A recent survey by the American Pet Products Association noted that about 5.6 million households in the U.S. owned a reptile or amphibians in 2012. Another survey pointed out that the industry was making annual revenue close to a billion U.S dollars.
What is traded
The team analysed the available literature to find the traded amphibians around the globe and also looked at the amphibian database AmphiBIO and AmphibiaWeb to understand the physical characters and reproductive capacity of each of the traded species. They also noted the status of the species according to the International Union for Conservation of Nature.
Six amphibian families were the highest traded - salamanders, frogs and toads, followed by caecilians (limbless amphibians that look like snakes).
The top species (in terms of number of individuals imported) in the USA were: Western dwarf clawed frog, Oriental fire-bellied toad, African clawed frog.
The team noted that the species with larger bodies, wider distributions, and also species that had indirect development (where the embryo develops into a mature individual without larval stage) were preferred. This proves that species that are easy to collect and rear in captivity were the most traded.
Nitya Prakash Mohanty, first and corresponding author of the work published in Biodiversity and Conservation explains: “Amphibians are fascinating creatures that come in diverse life-forms: swimmers, climbers, burrowers and hoppers. These creatures are relatively smaller pets and probably easier to own than large mammals.”
Another paper published by his team in March looked at YouTube videos to understand why people prefer to have a pet amphibian. “There are thousands of videos which show pet frogs or salamander eating and or just walking around. I think it gives people an opportunity to observe or even handle a wild creature,” adds Dr. Mohanty. “Human preferences are not that easy to understand” he chuckles.
He explains that some people after buying these amphibians release them into the wild thinking it is an act of kindness or when the cost of ownership become too high. But the introduction of a species beyond its natural geographic range can harm native species. It can also lead to the spread of new diseases.
Studies have shown that globally over 100 amphibian species are marked as invasive and with the growing pet trade, these numbers will soon rocket up.
“Our models could be improved with more information about what attracts humans to keeping amphibians as pets. For example, bright colours and ornaments are likely to play a role in choosing an exotic pet,” says John Measey, Principal Investigator of the team. "Our exercise was to look at amphibians in the pet trade, but the same approach could be taken with any taxonomic group to provide predictions about the future of the trade."
He adds that keeping a pet requires dedication and responsibility.