The biggest-selling pet snakes and lizards are also the most likely to be released by their owners and to potentially become invasive species, according to a Rutgers study in the Journal of Applied Ecology.
The study by Rutgers University–New Brunswick ecologists shows how the exotic pet trade has become the primary means by which reptiles and amphibians arrive in non-native lands and become ecologically damaging invaders.
Researchers documented 1,722 reptile and amphibian species in the U.S. exotic pet trade from 1999 to 2016. They compared the list with previous research and data from a citizen science project that records sightings in the U.S. of non-native species, and found that the most popular pets – those imported in high numbers and sold at low prices, usually when they’re small and cute – are the most likely to be dumped into the wild later on.
“The owners may underestimate the space and costs needed to keep such animals as they grow into adults. Boa constrictors and reticulated pythons grow over 8 feet long. African clawed frogs and Russian tortoises live 30 years or more,” said Oliver Stringham, a Rutgers doctoral student and lead author of the study. “Not wanting to euthanize, owners may resort to releasing them instead.”
Released exotic pets can harm native wildlife as predators, competitors for food, and disease carriers. The Burmese python, for example, which grows up to 18 feet long and has been invasive in Everglades National Park since the 1990s, has caused a severe decline in native mammals and birds.
The study recommends providing potential exotic pet owners with information about the future growth and lifespan of an exotic pet, along with the ecological damage that can result from releasing them, and a list of safe places to surrender them, including shelters, rehoming initiatives and buy-back programs, to avoid future releases into the wild.
Julie Lockwood, the study co-author and a professor in the Rutgers-New Brunswick Department of Ecology, Evolution, and Natural Resources, said, “While it might not be possible to fully prevent the release of exotic pets, reducing the number can be an effective way to prevent new species from becoming established and potentially invasive.”