Stop the Illegal Wildlife Trade: Global pet sales fuelling spread of invasive species, study finds

The multi-billion dollar global pet trade sees tens of millions of animals traded each year, but new research warns that invasive species are “strongly” overrepresented, with significant risks to the world’s ecosystems.

Since prehistoric times our own species has played a major role in moving plants and animals around the world. Historically this was largely for agricultural purposes and has contributed to the success of our own species.

However, due to the growing pet trade, the rate and volume at which species are traded around our planet has “rocketed”, the researchers said, and even poses a threat to our own species.

Pets are often purposefully released by their owners, or can accidentally escape. When this happens outside the animal’s native range it can threaten biodiversity, disrupt ecosystems and impact agriculture and human health.

New research by Swss scientists examined 7,522 traded vertebrate species and revealed the international pet trade routinely favours the sales of invasive species.

Dr Jérôme Gippet and professor Cleo Bertelsmeier from the University of Lausanne said: “In the last decade alone, billions of plants and animals comprising thousands of species were traded annually, fuelling a multibillion-dollar global business. In particular, the demand for nontraditional (also known as “exotic”) ornamentals and pets - organisms without a long history of domestication - has grown.”

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The research reveals how the numbers of invasive species being traded around the world is rising with the value of the global pet trade.

“We show that invasive species are strongly overrepresented in trade across mammals, birds, reptiles, amphibians, and fish,” the authors said.

But until now it was unclear whether this had occurred because, over time, pet species had more opportunities to become invasive, or because invasive species have a greater commercial success.

To address this, the researchers focused on an emergent pet trade in ants, which they said is too recent to be responsible for any invasions so far.

Nevertheless, they discovered that invasive ants were similarly overrepresented, demonstrating that the pet trade specifically favours invasive species.

“We show that ant species with the greatest commercial success tend to have larger spatial distributions and more generalist habitat requirements, both of which are also associated with invasiveness,” the authors said.

The results also revealed that invasive species represent 12.6 per cent of the pet trade and are 7.4 times more frequent in the pet trade than in the global pool of vertebrate species.

Similarly, invasive ant species in the pet trade are 6.6 times more common in the pet trade than in the global species pool and sold by 1.7 times more sellers than noninvasive species.

According to the authors, strict international regulations should be implemented to curb the global spread of invasive species and people should be encouraged to purchase pets native to their area.

“Our findings call for an increased risk awareness regarding the international trade of wildlife species as pets,” they said.

The research is published in the Proceedings of the National Academy of Sciences.