Wildlife and photography are the two great loves of David Plummer's life. His earliest memory is of studying woodlice, aged two, and by eight he'd got his hands on his first SLR – a secondhand Prinzflex with a 135mm lens, loaded with Fuji Velvia 50 – and started to develop his imaging skills. After a few diversions – including six years as a police officer in the East End and a stint working in the Caribbean – he turned pro in 1999.

Ten years on, with a successful career as a wildlife photographer, guide and conservationist that took him all over the world, he put his new and increasing exhaustion down to turning 40 and working too hard. Then he started to notice a slight tremor in his left arm that became more marked over the ensuing weeks. Six months and a battery of tests later, a neurologist confirmed that David had Parkinson's disease.

After the initial shock of the diagnosis, when he feared it meant 'game over' for life as he knew it, David chose to squeeze every last drop out of what could potentially be a shorter photography career than he had ever envisaged. In the subsequent seven years, he's continued to travel, leading wildlife photography tours to the Galapagos, India, Rwanda, the Masai Mara, the Pantanal in Brazil, and Hungary; he's bought 11 acres of ancient woodland near his West Sussex home, which he carefully manages to create the best possible opportunities for images; and he continues to work as a conservationist, ecologist and eco-tourism expert, as well as running the hides at the 3,500-acre Knepp Castle Estate Wildlands, Europe's biggest lowland rewilding project.

David's latest project is a book, 'Seven Years of Camera Shake', featuring his work since diagnosis. He crowd-funded the £18,000 necessary to secure a publishing deal for it in just three weeks – indeed, the funding campaign was a major reason for going public about his condition, which he did in April, during a segment on the BBC's prime-time The One Show. The book is due to be published in 2017 by Penguin Random House, with 50% of the profits going to the charity Parkinson's UK, which David also supports very personally by mentoring people who have recently been diagnosed.

How did you get into wildlife photography?

Wildlife has been my passion since forever. I live and breathe it – it's what gets me out of bed in the mornings. As a kid I used to breed great crested newts and release them all over the place. I started off drawing birds, then moved into photographing them when I got my uncle's old Prinzflex, a Dixon's own-brand SLR. I used to look at Nikons and think, 'That's what I want.'

Photography went by the wayside for a while as I got older. I had no money for it. Wildlife photography has never been cheaper than it is today, but I couldn't afford it back then. So I started work: as a police offer in East London for six years, then for two years as a warrant officer on Grand Cayman in the Caribbean. While I was out there I began dabbling in photography again, and when I came back to the UK I seriously started getting into it. A friend working in a camera shop in Hammersmith got me a deal on a Nikon F70. I eventually lost it – in fact, I lost all my kit – at the business end of two guns in Brazil. Luckily I survived unscratched. I replaced it with the F90X and bought two more over the next few years, eventually going digital in 2005.

When did you turn pro?

I went full time in 1999 – I'd done eight years with the police, and I knew that if I didn't leave then I'd be stuck. I loved my time in the police, and I'm still in daily contact with my ex-colleagues, but I was a bit of a wanderer – I wanted to see more of the world. The Caribbean really opened my eyes to that. At first I was scraping a living, doing so many odd jobs on the side to survive, including social care, cleaning toilets and working in gyms. It was a struggle to make it all work.

People ask me, 'When did you get your big break?' but you don't get one; it's incremental, you just keep chipping away at it. Gradually it's built up to the point where I can turn down jobs, and business has gone ballistic these last couple of years.

What’s in your kitbag?

My main camera is the D4. I love it. It was an exponential leap in DSLR technology. The fact that it will fire so fast for so long – around 100 continuous frames in RAW non-stop – is amazing. It's a speed machine. The autofocus is amazing, and the ISO capabilities really help me on high-speed shots at dawn and dusk. I've used it for filming at ISO 204,800 and the results were grainy but still phenomenal. For stills I generally use the lowest ISO but I have gone up to the 12,800 range with usable results. I still use my D300 and D200 for infrared trigger and timelapse shots as I'm not too fussed about leaving them outside, but I certainly don't want to leave my D4 lying around!

My 200-400mm f/4 I use loads - it's my main lens for travelling as it gives me so many options, especially with the 1.4x teleconverter. I also love the 70-200mm f/2.8 – it's a lovely lens. Together, the 70-200mm and 200-400mm are the Nikon dream team, with wonderful bokeh. These lenses have it. I also use a 300mm f/4 for bird photography, and a secondhand 50mm f/1.4D for filming and time lapse – you can pick them up for £70, a real bargain.

How is the book progressing?

I have two tables full of pictures to sort through – the book is going to have around 200-250 of my best and favourite images, and I'm going for impact. Trouble is, I've been staring at the images for so long, they've lost any impact for me, so I need an objective opinion! But overall it's going well – the work, i.e. the photography, is done; it's just really sorting out the images and writing the stories behind them that I still need to do!

Why did you decide to get involved with Parkinson’s UK?

When I was first diagnosed I was desperate for more information – not the tranquilisers my GP prescribed. Eventually I contacted Parkinson's UK for help and they sent round a volunteer to talk to me about it, so eight months ago I started as a peer-support volunteer myself, mentoring people who have just been diagnosed. Despite the media image of Parkinson's being an old person's disease, there are an awful lot of younger people with it, and so many have contacted me since I've been talking about it. What really riles me are the lazy media representations – one newspaper interview I did recently was illustrated with an image of an old lady's hand being held by a young lady's hand. Exactly which one was supposed to be the one with Parkinson's?

Part of the reason for doing the book is that I'm trying to change the face of Parkinson's. It's not just a disease of the elderly, and it doesn't mean the end of hope. The important thing is that it's not a book about what Parkinson's has done to me. It's a book about what Parkinson's has not done to me. It's a showcase of what I hope is world-class work by someone who just happens to have Parkinson's. I don't want my book reviewed as 'good for someone with Parkinson's'. I don't want people to buy it because I've got Parkinson's. I want it to be seen to be good, for it to be bought for the imagery.

How did people react after you appeared on The One Show?

If I'm working I'm fully medded up and I can operate normally, but for the filming I agreed to come off the medication to make it more powerful. I got over 700 direct messages as a result of appearing, all positive. My Twitter went up by 650 in an hour, and a community of creatives with Parkinson's is now forming as a result of me talking about it.

There were a lot of personal messages, too, and many said my story was inspiring. But I wasn't doing it to be inspiring, I was just sharing the fact that I have a disability but here's what I can do with it. I want people to know that a disability like Parkinson's doesn't mean they have to limit their ambitions. Initially there were dark days when I thought, 'Why me?', but I recovered from them. We have no control over something like this happening to us, but we can choose how we react. I chose positivity. I realised that I could blame and curse, but it would be irrelevant. I had to make a decision to get on with my life and be happy. Ironically, being diagnosed has galvanised me to achieve more in what potentially could be a lot less time.

What’s your favourite type of photography?

When I first started I loved to shoot flowers and butterflies – it was all quite gentle, lots of woodland scenes. But in the last few years I've become a speed freak – my photography now is much more about speed and drama, it's more brutal. And of course using faster shutter speeds does help counteract camera shake!

I always want to push my photography, as the 'bait and perch' approach can be quite formulaic. I'm currently trying infrared sensors firing six inches from the owl. I've started doing a lot of timelapse, too – I was shortlisted for Wildlife Photographer of the Year in the timelapse category. It mixes music, which I love researching, choosing something different like hard rock or techno, rather than the usual Cat Stevens 'Morning Has Broken' – I like something punchier.

The main thing for me is that I've never photographed a single captive animal. All my shots are of wild animals out in their natural habitat. I am a pursuer of the elusive – not only do I only shoot wild animals, but I go for those that are hard to find and photograph, like owls. Actually, I'm a bit obsessed with owls. I'm currently doing a series of a family of little owls who have become so used to me that they'll come at my whistle, but they're still wild.

Some people think wildlife photography is serendipitous. It's anything but. In the real world, it's 15% photography, and that's the easy bit – it's the 85% everything else that's the real work. That's all about knowledge, reconnaissance, perseverance, providing perches, sitting in hides, being patient. It's taken 18 months to get those owls used to me. A lot of what I do is about persistence and discomfort; in Hungary last week I was up at 3am to be in the hide at 4am. At one point I was using a floating hide and ended up covered in leeches, some as big as my fingers. A lot of the time what I do is quite extreme, but it's fun.

Why did you buy your own woodland?

It was a spur of the moment thing. I was chatting to an old school friend about the wildlife-photography courses I lead, and we got talking about me buying a woods to give me complete control over what I do. So I decided to go for it, and I bought the first woodland I saw. It's about 30 minutes away from my house, at the foot of the Downs, an ancient derelict woods which I bought on an extended mortgage, and to a degree it's become another workplace – I do badger watches there.

What’s the best advice you’ve ever been given – and that you’d give?

Many years ago I was told by a music producer that in the creative world you have to get used to dealing with rejection. And my advice is be prepared for pure dogged persistence. Do a job and always learn from it, and change what doesn't work, so you reclassify failure as learning, like Edison and the light bulb…

And the future?

It's essential for me to continue being involved with wildlife. If I didn't take another photograph again I'd survive, but I couldn't survive without the wildlife. As long as I can see and hear it, I'll be happy. I'm certainly not curbing anything at the moment – why stop, why slow down? I suffer from insomnia so if I can't sleep, I get out there to shoot. I just keep on going. When I was initially diagnosed I thought that was it, but my photography has only got better. I fight this disease every morning when I get out of bed. It will defeat me, but for now I've got so much energy, I'm galvanised. I always was quite belligerent and strong-willed, but Parkinson's has honed my skills. If I end up in a wheelchair it will be a Davros one. I'll keep on moving, and I'll keep on being with wildlife.

For more information visit www.davidplummerimages.co.uk/