There’s long been concern about the exotic pet trade, but scientists don’t know as much as they’d like about the economic, social, and ecological factors that drive the trade – especially when it comes to people making decisions that lead to exotic pets becoming invasive species.
In some places, Indonesia among them, people are more likely to keep birds or fish than they are the dogs or cats commonly domesticated in the West. Yet the purchase of exotic pets in places like the UK and the United States continues to grow, while the rate in the U.S. doubled in less than two decades. The practice is taking off in places like Brazil, and has had a fast-growing foothold for years in China.
New research published in Frontiers in Ecology and the Environment explores what’s happening when people choose exotic pets and – far too often – release them into the wild, where they succeed as nonnative species.
“Some species, like goldfish or monk parakeets, have been standard pets for decades, while others only show up in the market for a year or two and then disappear,” said Dr. Julie Lockwood of Rutgers University, the lead author of the study. “But it is not entirely clear what is producing this dynamic, except to note that some species are easy to care for and breed well in captivity, and therefore don’t cost much to purchase.”
Hundreds of thousands of these pets are sold each year, and even with a small percentage of escapes or intentional releases, they have the potential to form wild populations. At the same time, new exotic trends emerge. Among examples are the live‐animal keychains sold in Chinese markets, made with live reptiles, amphibians or fish kept in pouches. Those animals that don’t die are removed from the pouches and kept in captivity or released into the wild.
People often choose pets because of a bandwagon effect that makes the species popular for a time, while status-symbol ownership drives other fads. These cases can lend themselves to higher rates of release later on, as is the case with the green iguana. It accounted for 46 percent of the total reptile trade in the U.S. between 1996 and 2012, and now there are established non‐native populations in several regions.
Up to 10 percent of aquarium owners release fish when it becomes too difficult or expensive to care for them, and that’s had big impacts in European Union waters as well as the U.S. There’s uncertainty on hard numbers of overall exotic pet releases, but there’s research to suggest the practice is highly underestimated.
So to understand how likely it is a specific kind of pet will become an invasive species, it’s become important to understand the consumers and market demand, as well as the species traits that contribute to its success in surviving as a nonnative species. The same is true for breeders, who in many cases choose species that are low-maintenance and therefore profitable. The pets are easy to handle, they have low mortality rates, and the same characteristics make it more likely that they’ll survive as invasive species.
“A better understanding of human motivations and behaviors is therefore critical for assessing invasion risks associated with the exotic pet trade,” the authors note, calling for more research on the integrated problem of economics, human behavior and species biology.
