More than half of UK residents in a Sheffield survey would welcome tortoises in their parks

The zebra result rests on a little over 100 people. The study surveyed more than 250 UK residents ^[10], and the 40% figure is a share of that group ^[15]. The published account does not say how respondents were recruited or how closely they match the UK population. The percentages describe the people who were asked.

The researchers were surprised themselves. Ross Cameron, the University of Sheffield horticulture professor who led the research ^[12], said: "We expected people to be fairly resistant to the idea of exotic, nonnative animals in their local park. But people seem to understand that the natural world is under pressure and that we may need to do things differently." ^[2]

The figures may not all be on one scale. The article reports respondents "happy to see" tortoises and bee-eaters ^[4] but "broadly open" to zebras ^[1]. If those were different answer options, the two results are hard to compare directly. The ordering by danger is clearer. The researchers propose that any introductions start with smaller, benign animals, and they acknowledge that apex predators and dangerous species pose problems both practically and politically ^[8].

The reason to ask at all is climatic. Cameron put the timescale in local terms: "London's climate is already projected to resemble present-day Barcelona by 2050. Plants that currently need careful protection from frost in British gardens could eventually thrive outdoors year-round." ^[17] He also argued the practice already exists in a looser form: "British parks and gardens have been hosting plants from around the world for centuries. What we're suggesting is that we start being much more deliberate about it, choosing species not just for their looks, but for the role they could play in sustaining ecosystems that might otherwise disappear." ^[14]

The thing this doesn't tell you is whether any of it would work. A questionnaire about attitudes ^[3] records what people say they would accept in principle. It cannot show whether a Hermann's tortoise would cope outdoors in a British park, or how neighbours would react once one was living there. I think the survey does weaken the assumption that the public would be the first obstacle, at least for plants and small animals. That holds only if a larger sample finds the same thing.

Cameron set the predators aside himself. "We're not suggesting that anyone will be encountering hyenas on their morning run anytime soon," he said ^[9]. The paper, titled "The Zebra in Your Back Yard!", calls for a nationwide debate on the purpose of Britain's green spaces and how they might help protect biodiversity worldwide ^[11][13].