It's 2am and the baboons that are spending the night in the rain tree beside the river have erupted with the frenzied barking of their alarm call.
In the background I can hear the reason.
It's the soft, seductive crooning of a hyena, a sound strangely at odds with the fierce predator behind it.
If it were a leopard, the racket would be 10 times louder. Leopards are night hunters and they can climb trees, which makes them a baboon troop's worst nightmare.
In the distance, a lion is calling intermittently, something between a grunt and a yawn.
Between me and them and whatever else lurks outside is only the thin canvas of my tent, which could be shredded by a single casual paw swipe - but it's best not to let your imagination run riot.
I'm canoeing Botswana's Selinda Spillway, a narrow waterway joining the northern section of the Okavango Delta with the Linyati swamps.
The delta is one of Africa's wildlife treasures, a freshwater filigree of rivers, swamps and islands covering most of the country's north.
The delta is the northern end of the Kalahari Desert, which is rescued from thirst by the waters that flood down from the Angolan highlands each year and spill across the 16 000 square kilometre wetland of the delta, searching for a route to the sea that they never find.
While the big rivers that feed the delta are a permanent fixture, the Selinda Spillway is capricious.
After a dry spell that lasted more than 30 years, it is only in the past three years that water has flowed in the spillway, bringing an explosion of wildlife to sandy plains.
Over that time, Great Plains, which also operates safari lodges in the region, has been offering canoe safaris along the spillway.
Over four days we're paddling 45km, a schedule that allows for long lunches, siestas and walks through the bush.
It's us alone.
We are the only humans in this region, the only people on the spillway.
In our group there are eight of us, which is the maximum for the canoe safari. Couples come mostly, typically 50-ish and well heeled.
Travelling in this pristine wilderness does not come cheaply.
We're paired in the broad-beamed, flat-bottom canoes, each with a padded seat and backrest. It's pampered paddling, business-class.
Point man in the lead canoe is Josh, our guide.
British, he escaped to Africa for his gap year, ended up in Botswana hanging around in safari camps and fell under the spell of the continent.
When we go walking, a leather cartridge belt is slung loosely around his hips, and a big-bore bolt-action rifle hangs over his shoulder, just in case.
After paddling for about 45 minutes, we pull in to our first campsite and there are five smiling faces waiting to haul us in.
At the centre of our campsite is a proper table with a tablecloth and napkins, and cutlery twinkling in the firelight. Apart from the lifting of glasses and forks to mouths, once in camp, we barely lift a finger.
Five staff is a lavish quota for eight guests, and we are truly pampered paddlers.
Food is one of the highlights.
Dollar, our cook, is a legend in this part of the world. With little more than a campfire to work with, he can produce a moist and succulent chicken dish with grilled vegetables and a tagine-style lamb that melts in the mouth.
We also have a choice of spirits, wines, beer and soft drinks. By some miracle, there is ice for our gin and tonics.
When we turn in that night, we discover a hot-water bottle tucked under the covers. In this dry, parched air, night temperatures in mid-year can drop close to freezing.
After breakfast we set off for a stroll. With the warm-animal tang of sage grass in our nostrils, we follow a set of leopard prints in the soft sand of a game trail.
A lilac-breasted roller loops overhead, performing the aerial ballet of its courtship. The huge and untidy nest of a hammerkopf spills from the upper reaches of a mopane tree and we stop to admire a yellow-billed hornbill, which looks like it has a banana mounted on its beak.
Out of the rising sun comes an eagle, harassed by a drongo asserting its territorial rights.
At a waterhole, we're watching impala when a family of dwarf mongoose, Africa's smallest carnivore, pop up from their home in a fallen tree trunk.
The skeleton of a male impala lies propped in a leadwood tree, the bleached ribs cradling a branch. It's the remains of a leopard kill, Josh tells us. The leopard hoisted the impala into the tree, where it could eat its prey safe from lion and hyena.
Walking through the African bush, it's the small wonders, the birds and tiny dramas, that excite as much as the fang-and-claw struggles at the pointy end of the food pyramid.
What the canoe safari delivers is an intimate connection with the African bush that you don't get any other way.
In a vehicle, African wildlife encounters are totally different.
When you set off across the tawny plain in an open-top safari vehicle, the game is unfazed. Leopard will stalk right alongside, gazing with steely eyes into the distance. Snoozing lions just metres away will barely raise their heads, and wild dogs will chase a fleeing antelope right over your bonnet.
Approach on foot, however, and you bring panic and dismay into the animal kingdom. A human on foot is a game changer.
We've walked in a big circle away from the river and are just looping back when Josh spots oxpeckers rising from the trees along the riverbank.
Oxpeckers are the beauticians of the African bush, cleaning ticks from the backs of big grazing mammals. Whispering, Josh tells us that there are buffalo in the mopane woodland, and the oxpeckers in flight mean that the buffalo are nervous.
We're 100m away when we finally see them moving among the trees. A Cape buffalo can weigh 700kg, packs a wicked pair of horns and can cover the ground at 14m a second, which is about what Usain Bolt does at full pelt.
Elderly male buffalo in particular will pick a fight with anything that moves. Yet here they are, 50 jostling beasts with shoulders like full-forwards on steroids, wide-eyed and closing ranks.
It's a sobering realisation but, in the animal world, homo sapiens walk tall and every other creature in the jungle knows it.
Even though they have no memory of hunting in this region, the animals' fear of us is part of their genetic bedrock.
The paddling day begins about 9am.
It's stroking the water rather than energetic canoeing. We're moving downstream in a lazy current along a shallow, reedy waterway that varies from about 10m to 25m across.
Only when the morning breeze kicks up do we need to apply ourselves with anything like vigour.
Sea eagles and darters watch us glide below, saddle-billed storks stalk along the banks.
In the papyrus clumps in midstream are painted reed frogs that serenade us in the evenings with their bell-like music.
After a couple of hours, we pull into the bank for lunch and a snooze in the shade. There's time for a dip in the cool water before we paddle on for a few more hours in the afternoon.
On the third day of paddling, late in the afternoon, we pass a hippo pool.
We've already stopped to allow a big bull elephant to cross the river and now the open water in front of us is filled with about 20 hippos and they aren't moving.
It is an unglamorous fact that the animal responsible for more human deaths than any other in Africa is neither the lion nor the crocodile but an ugly, short-tempered, weed-munching vegetarian.
Hippos are highly territorial.
They also lie on the bottom for long periods and if they surface when your canoe is passing above, chances are you will end up in the water.
This will cause upset and distress to the hippo, possibly triggering the flight-or-fight reflex.
Either way, if the hippo opens its jaws and you happen to be somewhere close, it's probably not going to be a happy ending.
We pull into the bank to consider and Josh orders us back in our canoes to proceed single file, nose-to-tail, hugging the left bank close to the reeds.
Half the group is across when a hippo charges, surging through the water, creating a powerful bow wave.
There's a crack like a pistol shot as Josh slaps the water with his paddle blade and the hippo stops. The rest of us file past while the hippo roars with triumph, broadcasting his victory to the world.
He's seen us off. You'd swear he was laughing. If a hippo could high-five, he'd be doing it right now. – WA Today