Behind the wheel of our Land Rover, Phinley Mwampole, our 24-carat guide, scanned the colossal, cloud-scudded African sky. This was curious, I thought, because we were supposed to be looking for lions.

"Vultures," he explained. "Where they are, where there are many, we can find what you are looking for." I craned. Five other safari companions, amply seated among three rows in our theater on wheels, craned too. One, a bona fide ornithologist and director of a regional zoo, put his binoculars to the test. Almost immediately he announced he had spotted the bird in question. It was circling lazily on a thermal 1,500 feet above us. "White-headed vulture, male," Phinley proclaimed, matter-of-factly adding: "They fly alone or in pairs. Page 174 in guidebook."

We'd been in the Southern African bush long enough by now to have shed any astonishment at our 40-year-old guide's ability to match every bird spotted to the exact page in our estimable, 525-page Newman's Birds of Southern Africa. At first we'd made a game, calling it "spot and awe.'' One of us: "There, there's some sort of bee eater.'' Phinley: "Malachite king-fisher." One of us: "Where?" Phinley: "Page 272." During separate game drives hundreds of miles apart over several days, in which we had collectively spotted or thought we had spotted more than 100 species (my notes reflect personal sightings of 63 species in three days), Phinley and each guide preceding and succeeding him, nailed this bird-sighting, page-collation exercise without fail.

There was a simple explanation. Most of the guides on our 10-day exploration of northern Botswana's alluvial flood plains and wetlands, surrounded by the great Kalahari Desert, had been born in or near the very bush where our luxurious camps were located. Several were offspring of Bushmen themselves, the legendary nomads of the Kalahari. They were escorting us into their backyards, introducing us to the plants and animals they had grown up with. During a nearly two-decade boom in eco-tourism, which employs nearly 45 percent of northern Botswanans, the government recruited them, first as game trackers, then to protect against poachers. Their excellence caught the attention of a forward-looking South African company, Wilderness Safaris, which is keen on sustaining local environments while operating 20 lodges and camps, including three where we stayed while visiting the Linyanti, Chobe, and Okavango Delta regions of northern Botswana.

These recruits were trained in special campuses affiliated with wildlife conservation and hotel management curricula at universities in Cape Town and Durban. There they honed their English and acquired impeccable social and narrative skills. When they returned to their assigned bush camps, each possessed the convivial aplomb of a five-star concierge. They had learned patience, along with a bias for efficiency, so they could deliver a maximum educational experience during four- to five-hour game drives, one each morning and one stretching from late afternoon-with a break for cocktails at sunset-into the night. So when a bird was spotted and a guest wanted to know the particulars, rather than stop the vehicle and thumb through the book, each guide had memorized it, bird by bird, page by page. On the other hand, if a vehicle laden with photographers wanted to linger while shooting a herd of kudu, that was fine with Phinley. But he also would allow that an even larger herd of elephants was gathered just up ahead.

"We are not looking for a bird by itself, or only some. We want many," Phinley told us as we watched that single vulture spiraling above us while others photographed dazzling bee eaters and basketlike weaver nests in the lee of thorn bushes. All the while he kept scanning the treetops. "There!" He pointed. We looked. No one could tell where there was. "One thousand meters. There," he said, point blank. He helped one of his guests train her binoculars on the target. She gasped. We rotated our binoculars. More gasps uttered forth progressively as each of us spied what had been out of sight of our naked eyes-all except for Phinley's, of course. On a pair of very distant dead thorn trees, their bleached-out limbs rising like white candleholders against gathering dark thunderclouds, perched at least 60 funereal-looking creatures-white-backed vultures. "They show us the way," Phinley said, smiling broadly. Then he grew unequivocal: "When we get there, do not stand up. Do not move quickly." No explanation was necessary. He put the Rover in gear and headed into the veldt.

How birds and animals could exist in this oasis that is Botswana's Okavango Delta and how we could be pursuing them overland is greatly due to an astonishing amalgam of sand and saliva-the basic ingredients of termite mounds. These grayish mud piles, often rising as high as 12 feet, dot the landscape of the Kalahari and Okavango. Without them, the world's most pristine ecosystem would not exist. During mid-morning tea near a water hole hosting half-submerged hippos, another of our capable guides (whose name is Paul Otsile but who calls himself "O.T.") explained this matter with the assuredness of a tenured professor.

Here is the expurgated version of his lecture: Termites eat and digest cellulose, which causes nitrogen-enriched decay. This decay is nature's mulch. Plants grow from it. Termites also retain relatively huge amounts of protein and fat. Animals thrive on protein and so termites attract predators-birds, reptiles, and animals. To protect themselves, they build nests, sometimes digging as deep as the water table. As they dig and digest, the detritus forms the base of their mound. From this base, they deposit their saliva mixed with Kalahari sand. This becomes primitive cement, the building block of their mound. More than 5 million can live in this mound and the tunnels that radiate from it to the savannah grasses they consume.

A fully mature termite mound can be more than 100 years old, O.T. explained. Each mound can support at least 10 succeeding generations of queens, capable of laying in a single day 30,000 eggs from which the mound's workers and soldiers are hatched. Prodigious spawning is necessary to balance the depredation from predators and natural causes. It is also common to see a mound apparently leaning against a tree. Actually, the tree grows from the termite mounds. And therein lies the essence of the Okavango ecosystem, which has evolved over more than a million years.

The termite mounds provide the only topographic relief in the otherwise flat, fan-shaped Delta, the world's only inland estuary. They are the keystones to the grassy, interconnected islands that withstand seasonal flooding from the Okavango River as it flows southward from the heights of Angola to dispense itself into the sands of the Kalahari. Sprouting from termite mulch and standing next to termite mounds, trees stay high and dry during the floods while tapping the water the termites have bored into beneath their mound during the dry season. With trees come leaves, and birds and animals seeking shelter. As leaves drop, as seed-eating birds deposit waste, and as animals dig and stir up the soil, the islands grow. They host hundreds of species of birds as well as hippos, crocodiles, other reptiles, elephants, baboons, various monkeys, zebra, kudu, impala, giraffe, cheetah, leopards, lions, and lesser hairy beasts in a more than 9,000-square-mile network of these islands (more than five times the size of the Sacramento-San Joaquin Delta).

Warthogs love the grassy islands, walking on bended knees to graze in the dry season when the grass is short and to excavate the ground when it is muddy. Their burrows attract elephants that deepen and broaden them as they bathe in the mud. The resulting depressions, called pans, catch and hold rain, and attract other Delta creatures.

At one of these watering holes, a herd of giraffe must have gathered not long before we began our game drive with Phinley. As they drank, a pair of lions, a male and female, lay in the tall grass, downwind, concentrating.

This was Phinley's opinion as, after much zigzagging through the bush, during which we flushed hyena and flanked more than 20 six-foot-tall ostriches, we came upon the freshly killed adult bull giraffe. From behind, even in its toppled state, the 18-foot, 2,500-pound beast looked stately, until we observed the bloody cavern where the guts had been before the lions went to work. In the dead trees nearby, the vultures waited their turn.

"It is usually the female that brings it down," Phinley said solemnly. He nodded upward, drawing our attention to an acacia tree 10 feet to our right. There, embraced in its boughs, 10 feet above the ground, was a female lion. She was gorged. Her belly was distended and she was panting hard. Her flanks bore fresh wounds, which Phinley took to mean that she had probably battled other lions to protect the kill for her and her mate.

Our guide gently nudged the Rover forward, stopping beneath a second acacia. Again he nodded upward, and the next thing, we were eye to eye with a huge male. Facing a lion for the first time on its turf forces on you a complete adrenal package of fear, awe, and ecstasy. It is a private feeling. You cannot look directly into those piercing amber eyes and disrespect the Setswana word naga. In English, the distilled version is wild. In either language, the word represents a feeling that takes hold-a sensation that you are an inconspicuous part of a ferocious yet self-restrained order of things. Your own mortal consequence is diminished by the indifference the satiated lion shows you, and you feel wild as well.

In the African bush, you are surrounded by wild indifference-what we quaintly call the "law of the jungle." Not long after leaving the reposed lions, our guide nodded upward again. Draped in the branches of a jacalberry tree, growing about 15 feet above a termite mound, was the savaged carcass of a freshly killed adult female impala, possibly from a herd we had photographed the day before. Mature impalas weigh as much as 120 pounds. Whatever dragged the prey up the tree must have been muscular and motivated. A magnificent male leopard, reclining in an acacia 10 feet above us, confirmed our surmise. Like the lion, its gaze was wild and fixed-but not on us. It was guarding its kill as a tawny eagle circled, landed tentatively, and took off when it sensed the leopard's irritation. This played out for about 10 minutes, when, with a display of its incisors, the leopard descended, passing within six feet of our vehicle. "Do not stand, do not move quickly." Some lessons are driven home indelibly.

The leopard sauntered past and turned evanescent in the tall grass. Suddenly, it sprang high into the tree holding the carcass and gazed down upon us with deep emerald eyes that looked as though they had been fired from the center of the earth. Was it lording over us? Or was it simply satisfied that the eagle had been expelled?

Wild places evoke a feeling that is both arresting and satisfying in its awesome simplicity-though not a reverie. Any detachment could cost you. A journey into the bush means paying attention-holding your breath as a leopard saunters within six feet; listening hard to the night sounds as creatures pursue one another outside your rondavel, with its polished hardwood floor; witnessing vast, scarlet sunrises; and in the evening, the lightning perforating the air as it illuminates the plain. It means realizing that the termite is no less significant than you or the lion or the leopard and all the other things under the sky.

Patrick Dillon is executive editor of California magazine. In 2007, Bear Treks will offer a trip to Botswana. See page 20 of Cal Discoveries (In July/August 2006 California Magazine).