Lost in the landscape: Wilderness and wildlife in Australia’s Top End

This sparsely populated region of Australia's Northern Territory is home to creatures that are both fantastic and formidable, says Mike Unwin.

"I do love Big Arse," murmurs Amy, fondly. "Trouble is," she continues, "he doesn't like me. And he doesn't like boats, either. Matter of fact, I think he only likes himself." It's early morning on Home Billabong – a narrow body of water in the Mary River National Park at the heart of the Top End, that northernmost bulge of Australia's Northern Territory. Our helmswoman Amy Ricketts is referring to the huge estuarine crocodile that has claimed this oasis as his own. All eyes scan the dark waters for any sign of the misanthropic reptile.

Crocodiles, it seems, have sunk their teeth deep into the psyche of Top Enders. Our guides, Gerry Van Wees and Luke Paterson from Intrepid Connections, have been regaling us with horror stories ever since we left Darwin. "Ah, look mate," said Gerry, as we trundled across a bridge over the Adelaide River, "you can swim there, but the last bloke who tried – well, they only found his head." Or words to that effect.

Estuarine crocs – known locally as "salties", to distinguish them from the harmless freshwater crocodiles, or "freshies" – are the largest reptiles in the world. This particular individual (for the sake of good taste, let's call him BA) is a five-metre monster: large enough to consider humans fair game and not above having a pop at boats. Today he's lying low, but we meet plenty of others. It takes just one glimpse of a snaggle-toothed snout to transform our entire landscape from idyllic to menacing.

Safely back at breakfast in the safari-tented seclusion of Wildman Wilderness Lodge, we learn that the emphasis around these parts is very much on harmonious relations with the local wildlife – whatever grudges it may nurse against us. This remote camp, which opened just last year, has impressive environmental credentials and is itself a fine example of recycling, having made a 2,800km road-train relocation from its original site near Cairns.

Deadly wildlife is one of Australia's more troubling USPs. And the Top End has its fair share. If the salties in the billabongs don't get you, so we are told, then it'll be the box jellyfish on the beach, king browns in the bush or red-backs in the dunny. Gerry points out, though, that crocs in Australia claim on average barely one victim a year, snakes even fewer, and nobody has died from a spider bite since anti-venom arrived in the 1980s. Any such deaths are, of course, individual tragedies, but visitors of a nervous disposition would do well to get these things in perspective.

Certainly the wildlife we have encountered so far – crocs excluded – tends more towards the bizarre than the lethal. It started just outside Darwin with a frilled lizard, a species endowed with an extravagant Elizabethan-style neck ruff that it erects to spook assailants. This individual opted for flight over fight, however, belting off on hind legs before scrambling up a gum tree and peeking anxiously around the trunk like a four-year old playing hide-and-seek.

Even the birds are odd. Back in the frangipani-scented lushness of a Darwin park, we found a roosting tawny frogmouth owl – a nocturnal weirdo with a gape wide enough to gulp down small birds whole. And at one roadside picnic stop we watched a male greater bowerbird meticulously rearranging the heap of decorative pebbles and seeds around his avenue of sticks – the idea being to seduce a female by means of DIY and home decor.

In fact, more than 400 species of bird, half Australia's total, occur in the Top End, and our list lengthens at every stop. The noisy and showy – cockatoos, lorikeets, galahs – are commonplace, while local specials include an elusive rainbow pitta, which we find hopping around the leaf litter at Howard Springs, and rare Gouldian finches, which alight at a roadside creek, their plumage straight from a children's colouring book.

From Wildman Wilderness Lodge we continue east into the wilds of Kakadu, Australia's second biggest national park. During "The Wet", which runs from December to March, floods transform much of its savannah into a vast wetland. Now, however, it is Gurrung – the hot, dry season – and wildlife watchers flock to Yellow Water, one of the park's few areas of permanent water.

At dawn the next morning we join the flotilla of tourist boats. Birds, again, are everywhere: jacanas pick their way over lily pads; pied herons perch in pandanus palms and a white-bellied sea eagle splashes down to snatch up a fish. A bigger splash follows shortly afterwards, when the lunge of a lurking saltie sends thirsty wallabies bounding up the bank to safety. "Agile wallabies," explains Luke, helpfully identifying the species. Just as well, I think, as the murderous reptile sinks back unseen among the roots and waterweed.

Our camp, Gagudju Cooinda Lodge, is bang in the middle of Kakadu and just a stone's throw from Yellow Water. So that evening, after enjoying kangaroo steaks al fresco, Luke takes us back for a peek at the billabong's nocturnal life. From a wooden boardwalk, under jetty lights, we watch catfish, saratoga and archerfish cruising beneath the planks, the last of these able to gun down insect prey with a pinpoint jet of water. My torch picks out an exquisite pygmy tree frog clinging to the handrail. And best of all, a chance sweep of the beam reveals the patterned coils of a young carpet python, draped over a fallen log. "Beauty!" whispers Luke, as we creep closer to fire off the requisite snaps.

Kakadu owes its World Heritage status partly to its myriad sacred sites. Indeed, people have lived in the Top End for over 64,000 years, making it the oldest continuous human settlement in the world, and today the aboriginal community owns 65 per cent of the park. Some families still pursue a semi-traditional lifestyle, harvesting bush tucker and observing ancient traditions.

It is for a closer look at this heritage that we bid goodbye to Luke and Gerry at Jabiru Airport and fly east, hopping over the escarpment that marks Kakadu's eastern boundary and onward to the rugged wilderness of Arnhemland. From the air we can appreciate the true emptiness of Northern Territory: this state is six times the size of the UK, after all, yet home to fewer people than Plymouth. Below us the terrain rolls out to the horizon in model-railway clarity, with sand rivers and sandstone ridges transecting the endless carpet of savannah. Our shadow sweeps over the East Alligator River and up on to the stone country of the Arnhemland plateau. There is not a road in sight, not a glimmer of humanity.

Here our base is Davidson's Arnhemland Safari Camp, where the cabins are discreetly smuggled into the bush and aboriginal artefacts adorn the dining room walls. Owner Max Davidson is an honorary custodian of the area's sacred sites, which means that his guests get to see things that are off-limits elsewhere. For the next two days our guide, Clare Wallwork, leads us across billabongs, through paperbark swamps and up rocky outcrops, where overhangs are emblazoned with rock art. There are ochre handprints, chalky echidnas, fork-tongued goannas. "For blokes, this was like Playboy magazine," explains Clare, indicating the swollen breasts and genitals of the female figures etched on the sandstone.

The artworks are multilayered, literally. Each is painted to tell a story, so once completed it is no longer of any value and the next story is painted on top. Most spectacular is the rainbow serpent: a five-metre-long, dragon-like beast, born of creation myths, that is depicted in startling detail across a cave ceiling.

More disconcerting – at least to modern sensibilities – are the human remains that litter the darker recesses. In traditional culture, Clare tells us, those who died were afforded 10 days' "sorrow time", while the community mourned their passing. The body was then wrapped in paperbark, deposited on a cave shelf, and nature allowed to take its course. Among the scattered skulls I spot various artefacts – an old tin can, a medicine bottle – and Clare shows us a "travelling stick", on which the journeys of its owner's lifetime are notched in the polished wood.

By now I'm seeing see the local wildlife from a new perspective: those huge flocks of magpie geese are a life-giving food source; the vivid blue and orange Leichardt's grasshoppers are a cave-painter's colour palette. Clare even persuades me to sample a green ant. Clutching the insect's head between finger and thumb, as bidden, I lick its abdomen and taste an instant rush of sweet lime. Then I set it back on its leaf, unsure which of us is the more traumatised.

Head south along Kakadu's sandstone escarpment and you reach Nitmiluk National Park, location of Katherine Gorge. This celebrated landmark, which comprises 13 separate gorges carved out by the Katherine River, marks the final destination of our Top End tour. Beside our accommodation at Nitmiluk Chalets we find an inviting pool and an excellent visitor centre, which explains the area's spiritual importance to the indigenous Jawoyn community, which owns and manages the park. But the main event is down at the jetty, where as the shadows begin to lengthen we board our boat for the Nabilil Dreaming Sunset Cruise. This is certainly going out in style: the towering canyon walls turn from gold to red as we head upriver, knocking back the local wine and tucking into a groaning candlelit buffet. Thankfully our guide Jamie Brooks keeps a clear head. "The emergency exits are here, here and here," he quips, pointing overboard. "And don't worry: salties don't often make it this far upriver."

I am still pondering that word "often" when we take to the river next morning with canoe guide Mick Jerram. But this final adventure proves to be a blissfully gentle one, and our quiet progress downstream produces yet more wildlife surprises: Mick points out wedge-tailed eagles high overhead, black flying foxes flapping out from their riverbank roost and – most unexpected – a car door-sized freshwater ray, which undulates over the riverbed like a Rolf Harris wobble board.

No final crocs then, to round off our trip. Not even a small-arsed freshie. But that's fine, I reflect, as we hit the road and make for Darwin Airport. Not every story needs a snappy ending.

Travel essentials: Northern Territory

Getting there

* Darwin can be reached from Heathrow on Qantas (08457 747767; qantas.co.uk) via Singapore (the second leg is operated by subsidiary Jetstar). From 26 March, SilkAir, the short-haul, full-service operation from Singapore Airlines (0844 800 2380; singaporeair.co.uk), launches flights from Singapore, with connections from Heathrow.

* Audley Travel (01993 838 810; audley travel.com) offers a nine-night trip to the Northern Territory (Darwin, Kakadu, Arnhemland and Katherine Gorge) from £2,750 per person, including flights from Heathrow, car hire, sightseeing and accommodation, of which three nights is spent at Wildman Wilderness Lodge. A 12-night trip taking in Davidson's Camp in Arnhemland costs £5,100.

Visiting there

* Intrepid Connections (0800 781 1660; connections.travel) offers small group trips in Australia, including the Northern Territory.

Fisherking Safaris (00 61 0432 949 817; fisherkingsafaris .com.au) offers one-day bird-watching tours from A$180 (£122) per person.

* A three-day Katherine River canoeing tour costs from A$780 (£530) per person with Gecko Canoeing (00 61 8 8972 2224 geckocanoeing.com.au).

Staying there

* Mantra on the Esplanade, Darwin (00 61 7 5665 4416; mantra.com.au). Doubles start at A$158 (£107), room only.

* Wildman Wilderness Lodge, Mary River Wetlands (00 61 8 8978 8955; wildmanwildernesslodge .com.au). Tents that sleep two start at A$490 (£333), half board.

* Gagudju Lodge, Cooinda

(00 61 8 8979 0145 gagudju- dreaming.com). Doubles start at A$210 (£143), room only. The Lodge also operates Yellow Water Cruises through Kakadu's wetlands, starting at A$85 (£58) per person.

* Davidson's Arnhemland Safari Camp (00 61 8 8927 5240; arnhemland-safaris.com). Tents sleeping two start at A$1,400 (£952), full board.

* Nitmiluk Chalets, Nitmiluk National Park (00 618 8972 1253; nitmiluktours.com.au). Chalets sleeping two start at A$185 (£126), room only.

More information

* Tourism Northern Territory: australiaoutback.com