In the age of social media, the battle against invasive species in nature is increasingly unfolding online. A new study analyzing over 500,000 tweets posted between 2006 and 2021 examines public discourse around invasive species on the social media platform Twitter, which became X in 2023.
The study by an international team of researchers, including an ecologist at Penn State, was recently published in the journal Ecology & Society. The team found that mammals, especially urban pests like cats, pigs and squirrels, dominated online conversation with aquatic habitats and island ecosystems as frequent backdrops for viral posts.
Deah Lieurance, assistant professor of invasive species biology and management at Penn State and co-author on the study, explained that biological invasions have cost the North American economy $1.26 trillion over the past 50 years, so managing invasive species is vital for both ecosystems and the economy.
"Invasive species management isn't only a scientific challenge, it's a social one," she said. "We have to understand what the public conversation is - and it's not just the message; it's the messenger that counts."
The study found that just 1% of users were responsible for 60% of retweeted content. Among the most influential voices were not only scientists and conservation groups, but also celebrities, politicians and activist accounts. Posts by figures like YouTuber Logan Paul and former Senator Al Franken sparked massive engagement around lionfish and Asian carp, respectively.
"This concentration of influence is significant," said Susan Canavan, lead author on the study and honorary researcher with the College of Science and Engineering at University of Galway. "A small number of voices shape how millions of people understand invasive species."
She explained that the patterns the team found have important implications for conservation communication and policy.
"We had a unique opportunity with Twitter's free academic access to understand what drives public attention to invasive species at a scale that had not been done before and where the gaps lie relative to scientific priorities," Canavan said.
The researchers used advanced text-mining techniques to analyze hundreds of thousands of tweets containing the term "invasive species" to identify trending topics, influential users and geographic hotspots. Florida and the Great Lakes emerged as key regions of concern and hashtags like #ProtectCleanWater and #InvasiveSpeciesWeek helped rally support for management efforts.
The study found that cats topped the list of most-mentioned species. Despite being beloved pets, cats have contributed to 63 species extinctions globally and kill over a billion birds annually in the United States alone, Canavan explained. Pigs, dogs, squirrels, goats, rats and horses were also frequently mentioned in tweets.
"It turns out that mammals like cats, pigs and squirrels dominate online discussions about invasive species, even though plants and insects are often the bigger ecological threat," Lieurance said. "That tells us a lot about where public attention is focused."
This focus reflects what ecologists term "plant blindness," Canavan explained. Despite plants comprising 57% of endangered species and an invasive plants can be highly destructive, they received disproportionately limited attention in online discourse. Plants generate less than 4% of conservation funding, a disparity that social media patterns both reflect and potentially reinforce.
"Some of our most damaging invasive species are plants, but they don't capture public imagination the way animals do," she said. "When invasive plants are invisible in public discourse, building support for their management becomes exponentially more difficult."
The researchers also analysed how news outlets shape public conversation around invasive species online. Articles from The New York Times and CBS News proposing edible solutions to invasive species - like turning lionfish and feral hogs into dinner - triggered spikes in online engagement. Use of vibrant language also played a role in engagement.
"One article described tsunami debris as a 'dirty needle' injecting invasive species into our ecosystem," Lieurance said. "That kind of imagery sticks."
The researchers made the case that social media remains a vital tool for conservation. By understanding what captures public attention, scientists and policymakers can better align their strategies with societal concerns.
"If we want to manage invasive species effectively, we need to understand how people talk about them and who's shaping that conversation," Canavan said.
She added that their research quantifies previously anecdotal observations about which species and narratives resonate with non-specialist audiences - and losing access to this data could leave scientists blind to public perceptions in the future.
"Thankfully there are other platforms that are proving to be a strong alternative to Twitter, with a growing and active community of scientists joining every day," Lieurance said. "These platforms have attracted researchers seeking a more collegial space for scientific communication and their data capabilities can facilitate similar research moving forward."
Other authors on the paper are Pavel Pipek, Petr Pyšek, Ivan Jarić and Ana Novoa of the Czech Academy of Sciences; Kim Canavan of Rhodes University and University of the Free State; Kevin Healy of the University of Galway; Zarah Pattison of the University of Stirling; and Emily A. Stevenson of Newcastle University. The Czech Science Foundation funded this research.
