Try a quick test. Name one invasive species that lives in your country. Not one you have heard of on another continent. One that is actually present where you live. If you struggled, you are in the majority. A new global survey found that only about 42% of respondents could name at least one invasive alien species occurring in their own country. The question asked people to name a species present in their own country, not simply any species they had heard of.
What Does Invasive Alien Species Mean?
An invasive alien species is a species moved outside its natural range by human activity that then causes harm. Harm can mean damage to nature, to livelihoods, or to health. The word ‘alien’ is a technical term here. It does not mean foreign in a cultural sense, and it does not mean every introduced species is bad. Many introduced plants and animals cause no recorded harm. The survey was about the ones that do.
This distinction matters because the public debate often collapses into good versus bad. The researchers warn against that shortcut. As Ross Shackleton, from the Swiss Federal Research Institute, put it in the institutional release: “The answer is not simply to tell people that alien species are ‘bad’.” Communication needs to explain which species cause problems, what those problems are, and why a particular action is proposed.
The Survey in Numbers
The study, published in iScience as article 117811 in volume 29, issue 11, is described as the first standardised global survey of public awareness of invasive alien species. The team was based in 18 countries and ran the same questionnaire in 54 countries on six inhabited continents in 23 languages. After screening, the sample held 20,420 people.
| Measure | Figure | What it answers |
|---|---|---|
| Respondents after screening | 20,420 | Size of the usable sample |
| Countries covered | 54 | Six inhabited continents |
| Languages | 23 | Standardised questionnaire |
| Could name at least one invasive species in own country | About 42% | Lead author quote in the release; paper is the authority |
| Distinct invasive taxa named | 225 | Total across all respondents |
| Most named group overall | Vertebrates | Most frequent group of answers |
The headline figure needs care. Institutional releases disagree slightly, with CSIC giving 58.4% unable and the Czech Academy saying about 40% able. This article uses about 42%, which is the figure given as a direct lead-author quotation tied to the exact question: able to name at least one invasive alien species occurring in their country. The DOI link above leads to the paper itself, which remains the authority. The University of Stirling release describing the study carries the same figure and quotations.
Which Species Did People Name?
Respondents collectively named 225 different invasive taxa. The three most common answers worldwide were invasive mosquitoes in the Aedes group, rats in the Rattus group, and water hyacinth. Vertebrates were the group named most often overall.
That pattern is revealing. The answers people gave most often were:
- Aedes mosquitoes, which spread disease and bite people where they live.
- Rats, which live close to homes, farms, and food stores.
- Water hyacinth, which visibly chokes rivers and lakes.
They are visible, or they bite. People tend to name what they encounter, not what ecologists rank as the worst threat in a textbook.
It also helps explain why awareness alone does not fix management. Knowing a mosquito bites is not the same as understanding how an invasion spreads or what control would involve. The biodiversity losses that invasions drive are documented in assessments such as the UN report that put 1 million species at risk of extinction, where invasive species sit alongside land use change, exploitation, climate change, and pollution. In Britain, the link is concrete: a quarter of native UK mammals were judged at imminent risk of extinction, with alien invasive species named among the leading causes, including disease carried by grey squirrels into red squirrel range.
Who Is More Likely to Know?
Awareness was uneven. Older respondents and those with more education were more likely to name a species. People in large cities also tended to show higher awareness than people in smaller towns or rural areas. The study found that sociodemographic status explained awareness better than the broader social and ecological character of the country where someone lived.
Put plainly, living somewhere with many invasions did not automatically make someone aware of them. Who a person is, in terms of age, schooling, and city life, mattered more than how invaded their country looked on paper. That is a correlation in survey data. It does not prove that age or schooling causes awareness, and it does not mean rural people care less. Access to information, schooling, media, and services differs by circumstance, and that difference shows up in the answers.
Knowing More Goes With Wanting Action, But Support Stays Low
People who could name a species were more likely to view invasive species negatively and to support managing them. That link ran through the data in a consistent way. Yet overall support for management was low. Most of the measures in the survey were backed by fewer than half of respondents, and the survey sample was an online, self-selected group, so it cannot be read as a national opinion poll.
The awkward part should not be softened. A large share of the public opposed most management measures, and measures aimed at vertebrates received clearly less support than measures aimed at plants or insects. The authors suggest this may partly reflect the emotional appeal of some vertebrates, especially mammals. That finding sits next to cases such as the controversial cull of Mauritius flying foxes, where control of a mammal drew sharp conflict. It is also worth remembering that habitat work often has wider backing, as seen in efforts to rebuild pollinator habitat with native plants, which show that people will act when the task is clear and constructive.
Crucially, the awareness-to-support link is an association, not proof that teaching people names will make them back culling or spraying programmes. The article must not imply that it will. Support depends on what is proposed, where, to which species, and with what alternatives on the table.
Why This Gap Matters
Invasion science has mapped where introduced species occur, how they spread, and what damage they cause. But control happens in society, not in a laboratory. As senior author Petr Pyšek put it in the release: “If people do not understand why particular invasive species are a problem and why management is necessary, even scientifically well-founded measures may be difficult to implement.” Opposition can stall a programme, particularly when control involves animals or methods people see as controversial.
The researchers point to schools, the media, and environmental education as long-term routes, plus training in sectors tied to introductions such as agriculture, forestry, aquaculture, and tourism. They also stress local knowledge and cultural perspectives. A good programme starts with public engagement, not with a decision announced after conflict has begun.
Frequently Asked Questions
What does invasive alien species mean?
It means a species moved by human activity beyond its natural range that then causes ecological, economic, or social harm. Alien is a technical term for non-native origin, not a judgement on worth.
What are some invasive species of animals?
In this survey, the most often named animals were Aedes mosquitoes and Rattus rats.
What are common invasive plants?
The plant answer named most often worldwide was water hyacinth, a floating plant that can cover waterways and deplete oxygen and light for native life.
Why do people oppose control measures?
The survey does not give one single reason, and reasons will vary by place and species. Support was lowest for measures aimed at vertebrates, which the authors link in part to emotional attachment, especially to mammals. Broader opposition likely reflects concern about methods, fairness, and whether the reasons have been explained.
The Test Worth Keeping
So keep the opening quiz. Can you name one invasive species present in your country, and can you say what harm it causes and what should be done about it? Most people cannot yet answer the first part. That is not a verdict on intelligence. It is a sign that knowledge about invasions follows circumstance and that support for action follows understanding rather than arriving before it. Closing that gap will take clearer explanations, earlier engagement, and honest talk about the measures people find hardest to accept.
