Hinchinbrook Island by Andrew Bain

Coconuts littered the beach but every one of them was hollow and fleshless. A small hole had been bored through the husks, giving the nuts the empty-eyed stare of a skull. New coconuts fell and by the next morning they, too, were hollow. The island was a killing field of coconuts. At dusk the culprits revealed themselves, not as great toothy beasts but as tiny things, part field mouse, part bandicoot, entirely adorable. They were the Hinchinbrook rats, the Lilliputian lords and masters of Queensland's Hinchinbrook Island.

Tucked into a mangroved corner of the north Queensland coast, Hinchinbrook is not one of the famous roll-off-the-tongue Great Barrier Reef islands. But it should be. Apart from a small eco-resort on its northern tip, the world's second-largest island national park is an original paradise. The only other human mark on the island is the unobtrusive Thorsborne Trail, a 32-kilometre walking track that meanders along its east coast.

Hinchinbrook's limited fame comes from this trail, but it is a celebrity confined largely to walkers. The Thorsborne Trail is arguably Australia's finest wilderness walk and permits are one of the most prized tickets in bushwalking. Only 40 people are allowed on the island at any time, with numbers strictly controlled by Queensland’s Department of Environment. Bookings, it warns, should be made six months ahead. Late cancellations are another hope and this was how I succeeded in acquiring a permit on a week's notice.

The Thorsborne Trail begins along Hinchinbrook's northern coast on Ramsay Beach, a long, matchstick beach, its southern end overshadowed by the block form of Nina's Peak. At the end of Ramsay Bay, an almost imperceptible track heads into the darkness of the rainforest and within an hour I had reached the pass beneath Nina's Peak.

Under the conditions of a standard Hinchinbrook Island permit, the island's mountains are off-limits, except for this 312-metre mountain, onto which forays are actively encouraged to sate the walkers' natural desire for views.

Which it successfully does. Most of the great photographic images of Hinchinbrook have been taken from this vantage point with its commentary-box view along Ramsay Bay and across the island's 17,000 hectares of mangrove growth. To the south, the view is all mountains and thick forest intermittently broken by brilliant blonde bays. The first of these bays is Nina Bay.

Make me a god for a day and place me in charge of beaches and I would create Nina Bay. Small, secluded, fringed by trademark coconut palms and set to a backdrop of 1100-metre Mt Bowen – Hinchinbrook's highest mountain – it is a stunning spot, which on a bad day you might have to share with three or four people.

I stopped to wash away the morning's tropical sweat and a couple of hours magically disappeared, thus launching a pattern of lethargy that would continue the length of the Thorsborne Trail. With Nina Bay, Boulder Bay, Little Ramsay Bay, Zoe Falls and Mulligan Falls strung like bread crumbs along the Thorsborne Trail, there are so many distractions that the business of walking can become secondary. For this reason Hinchinbrook's permit issuers insist a minimum of four days is needed to fully appreciate the trail, even though it is the length of a single day's walk on many other paths.

It was at Little Ramsay Bay, my first night's stop, that the Hinchinbrook rats made themselves known. I had seen their impressive coconut handiwork on Nina Bay, but the coconuts were an hors d'oeuvre. When the rats are not drilling through coconuts, they are thieving hikers' rations. Tents, backpacks, even tins are no defense. This native bandsaw will go through the lot.

A woman camped beside me lost her fork to the rats during that first night. Another couple told of rats running up the sides of their tent in efforts to reach the bags of food they had strung from ropes above them.

After three nights of this activity I could happily have fed every one of Hinchinbrook's rats to the island's other famous inhabitants, its crocodiles. You don’t get to be Australia's largest mangrove area without a few reptilian drawbacks.

North Zoe Creek, reached across a headland from Little Ramsay Bay, is the reputed home of one of the island's more notorious crocodiles, known to leave the creek and patrol the ocean off Zoe Bay, rendering it, the next camp spot, a definite no-swim zone.

Nobody has ever been taken by a crocodile on Hinchinbrook and, like most walkers, I didn’t catch sight of any. But when you stumble across a sign declaring, “Warning: Estuarine Crocodiles Inhabit this Area”, it causes a few anxious moments. Particularly when you’re standing in the middle of a swamp.

Despite setting out from Zoe Bay early the next morning with good intentions I completed a single kilometre by lunch, distracted for hours by the rock pool at the base of Zoe Falls and the view from the top of the falls, another of the trail's signature scenes – Zoe Bay underscored by the granite slabs that mark the head of the falls.

Turning upriver from Zoe Falls heralded a significant change in the Thorsborne Trail's character. It ceased to be a coastal walk, continuing instead through the forests that smothered the base of the island's mountainous spine.

It presented some amazingly rapid forest transitions. Out of rainforest, I stepped blinking into a sunlit melaleuca swamp for a short, almost subliminal, moment before again being engulfed by rainforest. Then, in an instant, I was in eucalypt forest, the division coming in sharp, definite lines.

Through this I came to Mulligan Falls, Hinchinbrook's last distraction. Rumor suggested it was the worst spot for rats and a python had apparently taken a liking to the toilet. Again, there was a hypnotic waterfall and another enticing swimming hole.

The temptation is to climb the enticing line to the top of the falls, but one person who tried came crashing down, breaking both elbows and most of his teeth. For a dentist, it was not a great career move.

At camp, in the dimming evening, a Hinchinbrook rat scurried across the foot of one of my walking partners, drawing a scream. While she was distracted, another rat leaped at her rubbish bag.

More screams and crashes came from the direction of the toilet, rat-related not python. The sole sanctuary was our tents, from where we could only hear the rats’ frantic activity, slowly abating now our food had been stored away. I dreamed of rats, not tropical beauty.