Bent over double, I'm shuffling forward through dense acacia thickets, one eye on razor-sharp thorns and the other on ranger Jannie.
He's silently beckoning me towards a crash of white rhinos who will charge us in an instant if they feel threatened.
This sobering thought is uppermost in my mind as I creep over the dusty ground obeying Jannie's hand signals and not daring to offer up even a murmur.
Sounds of dawn in the wilderness are all around. My mind and body are totally immersed in the moment and I feel a surge of adrenalin as we near a small clearing where the great beasts are browsing.
Earlier, our guide had left the Landcruiser and climbed a rocky promontory to locate the animals. Now, he is following telltale tracks in the sand.
A conga-line of other anxious animal-lovers is strung out behind me. A quick glance tells me they are nervously anticipating a close encounter of the herd kind.
We are all pretty intense as we continue to arch our backs and inch forward into the wind, obeying the safety protocols of a walking safari in the Sanbona Game Reserve in South Africa's Eastern Cape Province.
Our hunched posture is designed to present the short-sighted quarry with a typical animal profile - a harmless impala or springbok for example.
This is all very well but I'm conscious that I can't attempt to outrun a rhino. As a last resort safety measure, Jannie is brandishing a lethal looking Czech CZ.375 calibre rifle in his right hand, which he earlier assured us has never been fired in anger.
This is a great comfort given our vulnerable position, now just 30 metres from a herd of giant herbivores that have earned their place among the elite ranks of the Big Five that trophy hunters of an earlier era regarded as the most dangerous to stalk (elephant, rhino, buffalo, lion and leopard).
Today these powerful, intimidating animals attract serious photographers instead of so-called "great white hunters".
At a whispered word from our leader, I step into a gap in the foliage and see three rhinos with lowered heads grazing on clumps of dry grass. At close quarters they seem enormous, like massive dust-covered grey boulders. The nearest is completely immobile except for two curiously twitching ears.
A brightly coloured ox-pecker bird is busily probing for ticks on the thick hide. The rhino's lethal-looking first horn is a metre long.
Suddenly there's a movement and a swirl of dust in the air. A baby rhino reacts to our presence. His head swings round into a gap in the undergrowth and his eye locks on to mine in a rigid stare.
A ponderous adult rhino head then rises up and faces us. Can this short-sighted creature possibly mistake our guide's sturdy, red-headed, bi-pedal hominid frame for a cheeky impala?
Jannie gives the obvious signal: It's time to back-off and make a dignified exit.
Once we return to the Landcruiser, our guide draws from his inexhaustible store of bush lore to get us more acquainted with the seemingly docile herbivores.
"Rhinos are very private creatures," he tells us. They are not under a constant threat of predation like many of the other animals in the reserve, so they are content to browse quietly among the thickets in their own little world.
White rhinos have a very large head, which they keep lowered for much of the day, browsing grass, whereas black rhinos elevate their head to browse on leaves and twigs as well as grass, Jannie explains.
Adult rhinos can weigh up to 2500 kilograms but are surprisingly agile, running at 40kmh in short bursts.
Both species have grey hides but the white rhino is distinguished by its large head.
We absorb these facts quietly but then Jannie shocks us to the core with his next statement. "You are privileged to see rhinos in the wild in South Africa.
By 2018 our rhino herds may well be extinct. We are losing 100 rhinos each month to poachers in an epidemic that's plaguing all of Africa." The reason: A rhino's horn weighs around 4kg and can fetch US$50,000 per kilogram in the Asian market.
We learn that rhinos have roamed the earth for 50 million years yet in the last 50 years their worldwide numbers have declined by 90 per cent.
The situation is now so dire that all-out war has been declared against international crime syndicates who recruit struggling farmers to shoot or tranquilise the animals on game reserves and cut off their horns, which are then shipped to China and Vietnam.
For centuries, the Chinese have believed in the medicinal properties of rhino horn for curing headaches, diphtheria and food poisoning, as well as enhancing the libido as an aphrodisiac.
Vietnamese use the horn powder as a party drug of choice. Mixed with wine this drink is a way of demonstrating one's wealth and status.
Rhino horn comprises compressed strands of keratin, plus calcium and potassium, the same materials that make human hair and fingernails, hardly an elixir of good health. Since 1993 it has been illegal to use horn for medicinal purposes.
Jannie explains that the peaceful rhinos we have just seen are under constant surveillance by skilled trackers and anti-poaching personnel. They will endeavour to arrest poachers in order to trace the syndicates but if the officers are threatened they will shoot to kill.
In some areas the army has been deployed to support reserve staff, he tells us.
As we continue on the game drive, bouncing over the dry spekboomveld of straggling acacia, euphorbia and succulent bushes, I'm still trying to absorb these disturbing revelations.
We pull up beside a large rhino dung heap midden, which our guide describes in an unusual way. "What you are seeing is the rhino's current Facebook status."
He goes on to explain that the herd's home range is scent-posted by dung heaps, which serve as communication and marker points.
The big males scatter their dung with ritualised kicks and spray urine to define their territory, sending a clear message to every other rhino in the area.
The males can identify every female by hormones in their faeces. Sub-adult males dare not defecate near the bull's pile as that would be taken as a challenge to his authority over the herd.
I find this sort of detail fascinating. It helps me to understand these formidable creatures, but I cannot get the wholesale slaughter out of my mind.
The thought that heavily armed military specialists have to baby-sit rhinos in South Africa's game reserves to keep them alive is utterly appalling.
Overseas travel is all about experiencing other ways of life, even those involving poverty and cruelty, but this rhino scenario is emotionally draining. I have the feeling that coming to Africa is a travel experience that can shake you to the core.
An open letter to Asia seems appropriate in this situation: "Please help Africa to save the precious rhino."
Singapore Airlines flies from Auckland to Cape Town via Singapore. Getting Around Adventure World organises small group tours around South Africa in modern vehicles with local guides at each city to show you the sightseeing highlights.
Carry a supply of lower denomination currency as tipping is practised in South Africa.
Sanbona Wildlife Reserve Nestled at the foot of the Warmwaterberg Mountains, Sanbona has 54,000 hectares of wildlife reserve with indigenous flora and fauna, including the free-roaming, so-called "big five" beasts – lion, African elephant, Cape buffalo, leopard, and rhinoceros.
Accommodation options include Gondwana Lodge, Tilney Manor, Dwyka Tented Lodge and an Explorer Camp.
Paul Rush travelled to South Africa with assistance from Singapore Airlines and Adventure World.
- Fairfax Media