Cull of the Wild — Hugh Warwick on the Ethics of Killing for Conservation

How should we think about killing, introductions and “invasives” in a world we’ve already changed? In this episode we talk to Hugh Warwick — ecologist, writer and hedgehog champion — about his award-winning book Cull of the Wild and the uncomfortable question at its heart: can killing ever be conservation?

From hedgehogs on the Hebrides to rats on South Georgia, Hugh explores what happens when good intentions meet ecological complexity. We discuss the power of names, the moral weight of words like “pest” and “eradication,” and why conservation decisions always come with ethical consequences.

Expect humour, philosophy, and a few awkward truths — including why he thinks every scientist’s spreadsheet should have a column for cruelty.

Episode Highlights

• How the words we use — “pest,” “invasive,” “pet” — decide how animals are treated
• When eradication makes sense, and when it causes more harm than good
• The story of the Uist hedgehogs and the lessons of unintended consequences
• Why nature recovery is also people recovery — the need for social capital and empathy
• From philosophers to gamekeepers: learning from those we disagree with

Links & resources:

• Hugh Warwick — website  https://hughwarwick.com
  
  
• Cull of the Wild — buy / details:
  https://uk.bookshop.org/p/books/cull-of-the-wild-killing-in-the-name-of-conservation-winner-of-the-zsl-clarivate-award
  
  

The Leverhulme Centre for Nature Recovery is interested in promoting a wide variety of views and opinions on nature recovery from researchers and practitioners.

The views, opinions and positions expressed within this podcast are those of the speakers alone, they do not purport to reflect the opinions or views of the Leverhulme Centre for Nature Recovery, or its researchers.

The work of the Leverhulme Centre for Nature Recovery is made possible thanks to the support of the Leverhulme Trust.

Transcript

Stephen Thomas: Welcome to the Nature Recovery Podcast. We're going to take a closer look at some of the solutions to counter biodiversity decline, and we'll find out more about the people behind these ideas. I'm delighted that my guest today is Hugh Warwick — environmentalist, activist, hedgehog savior, ecologist, chorister, photographer, and an award-winning author with his new book Cull of the Wild.

Hugh Warwick: My real pleasure. I'm recording this just before I go and do a grown-up lecture at the university — which for me is exciting because I come from Leicester Polytechnic and mainly used to talk to the Women's Institute. Coming to a university research seminar feels very grown up.

Stephen Thomas: I was at Glasgow University doing English Lit, so talk about imposter syndrome.

Hugh Warwick: I win — I win.

Stephen Thomas: Colour/Cull of the Wild is great. My hypothesis while reading was that it's not strictly a nature book but more a work of philosophy and ethics that happens to include squirrels in the front cupboard. It’s a deep dive into how we think and talk about killing, control, our relationships with other species and ourselves. As I read chapter by chapter I kept thinking of that old “There was an old woman who swallowed a fly” idea — unintended consequences piling up. Were there examples from your research that really stood out as mistakes?

Hugh Warwick: There are many. One of the biggest unintended consequences is the evolution of consciousness — that led us to elevate our species above others, which I call a real mess. Classic cases include Mao’s sparrow campaign and, famously, the cane toad in Australia. Most unintended consequences come from deliberate introductions aimed at pest control. I avoid the label “pest” lightly — words we use to describe species influence how we treat them. The book focuses on conservation impacts because I needed a doable frame. The seed for the book was my third-year research — counting hedgehogs on North Ronaldsay in Orkney in 1986 to see whether introduced hedgehogs were reducing breeding success of Arctic terns and other ground-nesting birds.

I wanted the book to show the variety of ways people frame these problems. For example, John Tulloch the postman introduced hedgehogs to an island in 1974 to control garden pests — an apparently sensible idea that caused complications.

Stephen Thomas: Where a species is matters a lot — hedgehogs in Britain are beloved (Mrs. Tiggywinkle!) but where they’re introduced (New Zealand, the Uists) they can cause chaos. The book challenged me about what’s “good,” because it depends on place. We can’t reverse all introductions; what’s the way forward?

Hugh Warwick: I often say we must avoid sounding like an eco-xenophobe — “they don’t look like us, they’re causing trouble.” Take the Uists — the RSPB at one point wanted to remove hedgehogs introduced there because they eat bird eggs. I wrote to argue against outright killing, and I succeeded. Another good example is the brown rat: what we call it changes how we treat it. If it’s a pet rat, we care for it; a lab rat is protected by rules; a kitchen rat gets poisoned. Alex Simmons (deputy chief vet, RSPB ethics board) made the simple but powerful point that we need to think at the level of individuals, something conservation tends to avoid.

Stephen Thomas: I’m guilty — in forestry I accept deer culling as a management tool. If you name a deer and make a connection, it becomes much harder to cull. New Zealand’s eradication policies can be effective, but they also feel socially and ethically fraught.

Hugh Warwick: Absolutely. In New Zealand, invasive species are often used as a scapegoat for much larger historical degradations — megafauna loss, extraction, industrial agriculture. You have to work with social context. There are islands where they passed laws requiring domestic cats to be spayed and banning cat imports, while humanely removing feral cats — a gentle, community-based approach that worked because it respected people’s attachments and built social capital.

Stephen Thomas: You mention the role of science. How should science handle these ethical conundrums?

Hugh Warwick: Scientists now often put data into spreadsheets so economists can use it. I suggested in the book that we should have a column for cruelty or suffering in those spreadsheets — it’s subjective but important. For instance, Tony Martin’s mink removal plans are technically feasible but raise welfare concerns (risk of starving trapped mink). On South Georgia, removing rats with anticoagulants killed tens or hundreds of thousands of rats — enormous suffering, even if the conservation outcome was positive. We should acknowledge that suffering and factor welfare into decision making, along with feasibility and social buy-in.

Stephen Thomas: Social capital keeps coming up. Some things we can’t talk about politically — cats are politically untouchable, for example. Who do you need at the table to make these changes realistically?

Hugh Warwick: On-the-ground ecologists need social scientists and local communities. Conservation can’t be done purely academically. I cite a study (crudely remembered) where farmer attitudes and how they treated staff affected predator tolerance. Where people treated staff well, they had fewer conflicts blamed on predators. So you can’t separate ecological solutions from social context.

Stephen Thomas: You wrote about eradication versus control — Craig Shuttleworth told you that if you only control (harvest) a problem species you’ll never eliminate it; eradication is different and, if you don’t commit fully, you waste resources and animal lives.

Hugh Warwick: Exactly. Eradication requires commitment; otherwise you just keep killing forever. I described the hedgehog debate on the Uists — the initial plan to kill hedgehogs was poorly timed and welfare-focused arguments paradoxically prolonged the program, which meant more hedgehogs ultimately died. If you’re going to do something, do it as quickly and humanely as possible to reduce total suffering.

Stephen Thomas: Did writing this book change you?

Hugh Warwick: Yes. I began with strong views — I call myself a “bunny hugger,” I was a strict vegan for ten years — but talking to many philosophers, ecologists, gamekeepers and others made me more capable of nuanced thinking. I now describe myself as a reluctant utilitarian — trying to work out what produces the best outcome for species or ecosystems. A crucial lesson was the value of talking to people you disagree with; even when you strongly differ (for example on killing for pleasure), there is shared territory and common goals. Mary Midgley’s idea that we should learn from people we may feel disgust for stuck with me.

Stephen Thomas: What does “nature recovery” mean to you?

Hugh Warwick: Nature recovery, to me, is as much about people recovery as it is about nature. To have nature not diminish, people need to appreciate it and build social capital. Getting people nose-to-nose with a hedgehog is more likely to produce change than watching Attenborough on TV. In short: reconnect people to nature.

Stephen Thomas: If you could go, carbon-free, to any ecosystem in any time, where would you go?

Hugh Warwick: I’d go to New Zealand before human arrival to see intact ecosystems, then again now to see the transformation. Alternatively, back to pre-Neolithic Dartmoor or the Atlantic rainforest of the southwest of Britain to see that moss-and-lichen rich world — preferably with a surfboard so I can surf afterwards.

Stephen Thomas: Thanks for your work and your book.

Hugh Warwick: Award-winning, available in good independent bookshops and as a great audiobook. Thanks very much.

Stephen Thomas: You’ve been listening to the Nature Recovery Podcast with me, Stephen Thomas. Please subscribe and consider leaving a review or sharing this episode.