To Have or To Hold: Nature's Hidden Relationships

by Sophie Pavelle

A thrilling exploration of nature's symbiotic relationships, some comforting and familiar, others wildly alien, by the award-winning author of Forget Me Not .

What can nature teach us about living together? Investigating eight symbiotic relationships trying to survive the climate and biodiversity crises, Sophie Pavelle explains why it has never been more vital for us to understand symbiosis. Symbiotic relationships regulate ecosystems, strengthen resilience and bind pivotal connections.

Species living together in symbiosis is no accident – these dynamics evolved. Species form and sever alliances everywhere, from deep within temperate rainforests to the open ocean, quiet tidal pools or chalk grasslands, and nature thrives on relationships as glamorous as they are grotesque and as bizarre as they are engrossing.

In To Have or To Hold, Sophie relishes the interconnectedness between species and celebrates the relationships that underpin natural environments. Low-carbon travelling around the British Isles, she presents nature's frauds, fortune-tellers, misfits and cheaters.

The natural world is built on parasitism, a cunning blend of bargaining and exploitation in the name of survival. In our relationship with the natural world, are we the parasites? Will we continue to exploit nature's resources? Or will we vow to love and cherish what remains – shaping a more restorative life alongside nature – till death us do part?

Genres: Nonfiction, Nature, Science, Environment, Audiobook, Natural History

336 pages, Hardcover

Published July 1, 2025

Reviews

[Katrina Clarke · Rating 4 out of 5]

I enjoy Sophie's humour, musings, character, dedication to a muddy bike ride. She cares passionately about the natural world and in here book research she humbly and curiously approaches experts and the wildlife itself, a blank canvases asking what lessons can be learned.

This book depicts the symbiotic relationships between a variety of British species, and readdressed the idea of mutualism and benefit between these.

I really appreciated the variety of species and habits she visits (lungworm lichen my favourite of course). The depth of understanding gleaned from each and the resulting philosophising she does varies. It is a bit jarring to read but is an honest reflection of the knowledge and research that exists out there.

Wanna see sunfish and lie in a meadow watching orchids and to poke some leafy lichen.

[Leslie · Rating 4 out of 5]

A rich, captivating dive into nature's symbiotic relationships - how they evolved, how they work, how they are getting on in a changing climate. Equal parts infuriating, funny, informative, gross and awe-inspiring. There's too much to take in, which is kind of the point! We are all interconnected, often in ways we don't understand and sometimes ignore. We do so at our peril and at the peril of the millions of beings with whom we share this planet.

[Ash D · Rating 4 out of 5]

A (mostly) warm and fun read, travelling through Britain exploring nature and specifically some of its stranger configurations. I think what Pavelle does really well is to show and share her excitement and wonder, and pull you into it. This optimism is balanced against worrying concerns about the environment, backed with data observed by both Pavelle and the experts she interacted with.
However, a few caveats. I was a little disappointed that we didn't get to see more examples of symbioticism. Pavelle seems to believe that many of these relationships aren't quite 50/50 and indeed some of the examples provided were more akin to parasitism. I still learned a lot and found it fascinating though I was hoping for a slightly different educational experience. That's on the content.
On the style, while Pavelle's excitement does shine through, I found the jumping between topics within a chapter a little difficult to deal with sometimes. We could be in a forest at one moment, about to discover something and suddenly we are regaled with a tale of a bike ride and some observations along it. On top of this, some of the language struck me as a little 'younger', there were terms and colloquialisms that I've mainly encountered when chatting casually to folks around my age, rather than in a book. While I enjoyed this for the most part, I'm not sure if it will be everyone's cuppa.
With all that said, I do recommend this book to anyone looking to learn a little more about nature and the not-so-straightforward relationships some of her members share. But do be braced to feel a little depressed (or if you're lucky, motivated into action) as there is also a lot of information about the continuing degradation of the environment, be it in the woods, on the shore, or even in the sea.

[Zoe Langley-Wathen · Rating 5 out of 5]

I found this book both captivating and educating. Sophie Pavelle strikes a perfect balance between humour, heart and hard facts, making conservation accessible without ever oversimplifying. I learnt so many new terms and wildlife behaviours, and each chapter opened a window onto a fascinating corner of the natural world.

What really drew me in was the way Sophie incorporated her personal life and expeditions to find each critter, fish or insect. It felt like part science exploration, especially around the symbiotic relationships that tie species together, and part adventure memoir which I’d always lean towards in preference. That combination gave the book warmth and relatability while still being deeply informative.

The chapter on Sunfish was astonishing. I'd never realised just how bizarre and vulnerable this ocean wanderer is, or how much we still have to learn about its life. And the Lichens, wow! Who knew something so easily overlooked could be such a vital indicator of ecological health?

The book gave me much food for thought about how we perceive even the most pesky parasites and challenged me to re-evaluate their role in a balanced ecosystem. Every species has a story, and Sophie tells them with a blend of reverence and curiosity that’s super infectious.

I was lucky enough to hear Sophie speak in conversation with Jeni Bell (another author), at an event organised by FOLDE bookshop in Shaftesbury. Hearing her talk about the book in person only deepened my appreciation for the work and love poured into it.

Highly recommended for anyone curious about the vastness (and wonderful weirdness) of the living world and our place in it.

[Jon Bittman · Rating 5 out of 5]

Loved this interesting take on symbiosis and parasitism in relation to climate change. Well researched and filled with exciting factoids. Generally a (sort of) positive outlook on the growingly desperate climate crisis. Loved the balance of hardcore science with flashy prose and millenial pop-culture references.

[Kerry]

This book is so beautifully written it’s hard to believe you’re reading a nonfiction book, rather than a collection of short stories about wonderful mysterious organisms. All science should be communicated like this!

[Jenny D · Rating 5 out of 5]

Electric…I was simultaneously horrified and captivated! A formidable achievement to write a book like this on such a difficult, important subject.

[Jeni Bell · Rating 5 out of 5]

This is an absolute powerhouse of a book! Sophie Pavelle has really honed her (already impressive) skills for communicating the complexities of science in such an accessible way - To Have or To Hold truly shows that off. She is tackling the so-often-overlooked (and in some cases not easily studied) subject of symbiosis, and weaves it into such a beautiful story that really made me think twice about not just natures’ relationships, but our relationship with nature. This was a book that lingered with me long after I put it down. Beautifully balanced with all the light and shade, seriousness and humour, drama and joy of any good relationship story – it’s just this one features sunfish and mint-sauce worms!


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