Riding a clockwise path around the paddocks' perimeters, and finishing with a pass "up the guts", he only has eyes for rabbits.
His head swivels like a sideshow clown's as he paints the brown grass with the strong beam from a helmet-mounted lamp. "Let me know if you see one I miss," he had said before we set out, but I think he was taking the piss. After all, I'd earlier gawped myopically and said "Nope", when, before he had even turned the headlamp on, he spotted a morepork on a fencepost and said, "See that?"
Without warning, he throttles off, brakes. A silenced semi-automatic 22, shooting what he calls "slow, quiet" ammunition, seems to leap from the rack in front of him and he lies almost prone on the front-mounted box where he keeps his equipment.
Only when the gun spits do I see the rabbit, leaping at the bullet's impact (although I get better at spotting them when Ditch explains that he is aiming his lamp beam just below the target). Within seconds he is alongside his quarry, lifting it by the hind legs. If it is still alive, he breaks its neck with a small, almost tender twist of the wrist ("People think if you kill animals for a living, you have no regard for them," he says. "Nothing could be further from the truth.")
Later, on a flip-down tray at the back, he beheads and skins the still-warm carcasses. Each takes about six seconds. They look good enough for the window of a boutique butchery, but they're bound for the freezer, later to be sawed into cubes and sold as trap bait for stoats and feral cats. Some 25,000 rabbits end up this way each year, he says: "There's a nice symmetry about taking a prey item and turning it into bait for the predator."
Ditch's clients range from councils, farmers to golf clubs and sports grounds: the rogues' gallery of pests on his website goes from wasps to pigs. His pest-killing career started about 20 years ago, as a DoC trainee hunter on Rangitoto and Motutapu, getting rid of possums and brush-tail rock wallabies. The early experience made him fall in love with islands, he says, and he is justifiably proud of having led the slaughter of 20,000 rabbits on Motuihe.
The inner gulf island was a virtual desert in the 90s; it's a pest- and predator-free paradise now.
Foraging rabbits are destructive enough, but worse, they attract predators that, in environments such as Tawharanui, will kill protected species. "What we didn't understand when I started," Ditch says, "is that one of the best ways to get on top of your predators is to get on top of your prey numbers."
Shakespear Regional Park at the tip of the Whangaparaoa Peninsula is his latest success story: "It looks like we have achieved eradication, though you don't use that word lightly, because you have to take two or three years to prove it."
If he does prove it, there'll always be somewhere else to start shooting. That will suit Ditch. "Everyone has their calling in this world," he says with a boyish smile. "Some of us are lucky enough to find it."
