"Don't worry folks, we've taken out the crocodiles before today's tour," says tour guide Dee Dyer over the radio, as the convoy of buggies sloshes through a soggy underpass on its way onto the reserve. "Just joking, there aren't really any crocs - it's a bit too cold for them over here."
It might be too cool for crocs, but conditions on the edge of the Fens between King's Lynn and Downham Market are perfect for plenty of other creatures.
Five years ago farmer Ed Pope, wife Anna Hamilton, Miss Dyer and reserve manager Julian Stoyel began turning woods and former gravel workings into a 170-acre nature reserve with the aim of helping preserve some of the world's most-endangered deer and antelope.
Just over a year ago, they opened their vision - called Watatunga - to visitors. Since then thousands have been on a buggy safari through the park, where animals like Pere David's deer, Malayan sambar and mountain bongo range free and thrive.
Zimbabwean-born Miss Dyer provides a running commentary over the radio to each buggy, ad-libbing off-the-cuff as we turn each corner.
"That white stork you see over there, he's called Mr Miyagi," she said as we glimpse the great bird in the distance. Mr Miyagi, as in the teacher in the 1980s Karate Kid film series, she explains.
"His favourite food is grasshoppers," she adds. "So he kicks the grass to disturb all the insects and then he's just super quick with his great long beak chop chop, chop chop."
We left Mr Miyagi to his breakfast to try to find a mountain bongo, a rare antelope of which just 100 survive in the wild. A priceless calf was born earlier this year to one of Watatunga's two females and solitary male.
We bounced up and down wooded tracks, stopping every now and then to listen for the giveaway sound of breaking branches. But there was silence all around apart from an irate green woodpecker.
While we drew a blank on the bongo front, there was an encounter with an inquisitive Malayan sambar, along with sightings of blesbok and white-lipped deer, and a mouflon - a mouthy sheep with attitude, which does not need shearing because birds pinch its wool for their nests.
That's the beauty of Watatunga, you just never know what you're going to see," said Miss Dyer as we pass a trio of great bustards on our way back to the lodge.
Founder Ed Pope's vision began more than five years ago. Mrs Hamilton remembers the day he first showed her around.
"The whole place was just mud," she said. "So I was: 'Oh my goodness, what are you thinking of doing?'"
But Norfolk's newest nature attraction would amaze even its founders when it charged up its fleet of electric buggies and opened for business.
"This season we're getting near 7,000 visitors and I hope we'll be nearer 10,000 by the end of the season," said Mr Pope. "It's been staggering.
"What has really impressed me has been the feedback and how the concept has been embraced by the visitors and other conservation programmes all over the world."
Rare animals bred at Watatunga will eventually be returned to the wild. Miss Dyer told how Pere David's deer became extinct in the wild in its native China more than two centuries ago, but the species was saved by a captive breeding programme.
Closer to home, the reserve is taking part in a programme to rear the endangered turtle dove, of which around 40 were released last year. Some returned this year, after migrating to sub-Saharan Africa and back.
Mrs Hamilton said the reserve was evolving. A specially-adapted trailer can carry a wheelchair-user and up to two companions on a tour, while its holiday cottages also offer disabled-friendly accommodation.
School trips have proven popular, while a pop-up cafe is also in the offing. Tours must be pre-booked at www.watatunga.co.uk.
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