We are wobbling across the Serengeti in a tiny 10-seater aircraft when we first work out that something strange is going on. As vast, ochre-coloured plains strewn with wildebeest and gazelle open out beneath us, our pilot abandons the controls, rummages in his bag, pulls out a pocket camera and starts taking photographs through the window. We glance nervously at each other and at the 10,000ft discrepancy between ourselves and the ground. The pilot clicks contentedly away.
But perhaps we shouldn't have been surprised. Tanzania keeps doing this to you - thrusting so much natural beauty, such a diversity of wildlife, that it's all you can do to gawp and fumble for your camera.
This is a country famous for its obsession with conservation: since independence in 1961, a quarter of its land has been given over to burgeoning populations of lion, giraffe, gazelle, rhino, wildebeest and zebra, prompting controversial policies barring Maasai from cattle-grazing land that are only now being reconsidered. But tourists have only been cautiously welcomed too, so the horror stories of Kenya's Maasai Mara - Land Rovers as numerous as tsetse fly - are unheard of here. In Tanzania's northern circuit of game reserves, the trick is simple: build fewer safari lodges and charge visitors more. It works.
Lake Manyara
The flamingo-fringed shoreline of this vast saltwater lake is safari for beginners. The water and surrounding flats, lapping serenely at the western wall of the Great Rift valley, are home to hundreds of bird species and a few nonchalant hippo; no big game here, we are assured.
It's on that basis alone that we agree to leave the safety of our open-topped safari cruiser and take to mountain bikes under the tutelage of Jean du Plessis, a rugged adventure-holiday specialist and the type of man whom, one imagines, would be desperately unhappy in any profession not involving the imminent risk of attack by large and intemperate animals.
Talk about getting close to nature: Manyara's smaller birds glide within inches of your face; its purple soil gets lodged beneath your fingernails. It's not evident at first why the locals laugh so knowingly at us as we clatter through the village of Mto Wa Mbu en route to the lakeshore - but all becomes clear when we read, later, about the tree-climbing lions for which the area is famed, and about which Jean has thankfully omitted to inform us.
We collapse in a sweaty heap at Lake Manyara Serena Lodge, first of the four Serena properties where we'll spend the week. Like the others, it is a collection of what looks like cone-roofed Maasai huts on the outside, but suspiciously like luxury hotel bedrooms on the inside; this one is almost invisibly blended into the acacia-studded escarpment overlooking the lake. Breakfast and dinner take the form of simple buffets; game is strictly off the menu.
If only to shake off the animal-focused tunnel vision that grows on the visitor so quickly here, a tour of Mto Wa Mbu is a must. Despite its unpromising name - Mto Wa Mbu translates as "mosquito river"- the village is a nationally famous model of integration: the proud local boast is that 130 tribes live in harmony here.
Wesley Hans Kileo's Cultural Tour channels profits from the three-hour walk into village schooling projects. As a result, we are warmly welcomed inside villagers' mud-walled homes, corralled into complicated games by their children and invited to taste the acrid local banana beer - although, in retrospect, this may have been some cruel practical joke.
Mountain bike safaris cost $55 per person for a three-hour trek with Footprint Adventures, footprintadv@hotmail.com or satellite phone 0027117742380. Village walk, $45pp, organised through Footprint Adventures.
Ngorongoro crater
For anyone - like me - whose prior experience of wildlife-spotting consists of watching baboons defecate on your windscreen on a drizzly Sunday at the West Midlands Safari Park, a first glimpse of the Ngorongoro crater poses a serious risk of cardiac arrest.
The steep road from Manyara climbs into forests shrouded in cloud, past the watchful gaze of Maasai herdsmen in their vivid red capes, before reaching the 3,000m-high rim of the crater and - when the cloud eventually lifts - what has to be one of the world's great views. Its forests, swamps and lakes - a patchwork of greens and browns - are home to a concentrated profusion of Tanzania's finest: lion, elephant, rhino, wildebeest, zebra, buffalo, hyena, golden jackal, ostrich and crowned cranes.
"Those things can accelerate from zero to 50mph in, like, seconds," claims our guide, Hezron, referring to an elephant munching from branches nearby. It is not abundantly clear that the same could be said of our safari vehicle. Less alarming but just as memorable are the plentiful warthog, comically misformed creatures who trot affectingly past in little family groupings.
Descent into the crater is restricted to 4x4s accompanied by a national parks ranger, and giant gates across the access roads clang shut at 6pm sharp. Stay as late as possible, though: when the sun sinks towards the horizon, the light through the baobab trees takes on an ethereal quality, and the chances are maximised of seeing the crater's prized sight: a black rhino and its calf, making for the woods for the night.
Olduvai gorge
Amid all this furious fertility it comes as little surprise to discover that some of the earliest evidence of human life was found mere kilometres away at Olduvai gorge, a 90m-deep canyon just northwest of the crater. Here, in 1959, husband- and-wife archaeologists Louis and Mary Leakey found the skull of an upright hominid thought to be 1.8 million years old.
Today, for a nominal fee, visitors who manage to endure a lecture from resident archaeologist Ozias Sam Kileo can browse an informative if traditional museum on the site, complete with a series of lovingly framed prints recording a recent visit by Hillary and Chelsea Clinton.
• Olduvai gorge visitors centre, PO Box 7, Arusha, Tanzania (booking not required).
Serengeti
The pile-'em-high wildlife sights of Ngorongoro suddenly seem rather artificial and Disneyfied, though, when we arrive at our final destination: the sweeping, endless, rock-strewn plains of the Serengeti.
There is hardly a shortage of game, or visitors - more than 100,000 people visit every year - but their dispersal over the national park's 14,763 square kilometres accords each new sighting the palpable thrill of a genuine discovery: a cheetah, scanning the horizon for potential prey in the throbbing midday sun; a pride of lions tossing and turning in fitful sleep beneath a baobab tree; 11 huge crocodiles half-submerged in a stagnant gorge, jaws open for ventilation and in readiness for the next unlucky wildebeest to stray from its path and slip into the muddy water.
The exception to this less-is-more rule is to be found in the park's Western Corridor between May and July, during the migration of wildebeest, plains zebra and antelope from northern Tanzania to the neighbouring Maasai Mara.
And what an exception: on our second day in the park, rising early when the wildlife is most active, we drive for hours through countless thousands of lowing wildebeest, as far as the eye could see, scattering in front of us as we cut a swathe through their numbers. You know you have seen something pretty indescribable when the only comparisons that spring to mind are with nature documentaries on the Discovery Channel.
Hunting in the parks is strictly outlawed - the sound of gunshots is more likely to come from rangers shooting poachers with their automatic rifles - but there are plenty of grimmer sights for the seeker of gore. Witnessing a kill requires a lot of game drives and even more luck, but their bloody aftermath is everywhere.
We find a zebra, its carcass ripped open by some vanished predator, in the process of having its eyes sucked out and its ribs picked clean by a flock of hungry, croaking vultures. Members of our party voice loud disgust at the spectacle even as they eagerly reload their cameras.
A bush dinner is one of the more surreal ways to conclude a sojourn in the Serengeti - and one of the more alarming. For £35 a head, we're driven several miles from our lodge to a grassy clearing, where we find a crackling log fire, a table set in readiness, with bottles of Tusker beer and South African wine, and a chef preparing our food on a portable grill.
As the smell of succulent barbecued meat drifts across the lion-infested plains, it becomes rather easy to imagine that we will be constituting, rather than consuming, the dinner in question. Thankfully, though, we are joined by a warden with an AK47 slung over his shoulder who spends the evening patrolling the clearing's perimeter and, somewhat unnervingly, accompanying us on our trips to the isolated toilet tent in the trees.
We depart next morning from a tiny rutted airstrip, where, we are told, flights are often delayed for hours because of herds of wildebeest on the runway. Today, there's just a solitary warthog to be chivvied from the Tarmac: we're not going to get stranded here. Taking a last look at the endless, enveloping plains and the scattering of gazelle sprinting along the horizon, though, that suddenly seems a curiously tempting prospect.
Safari for beginners ... the essentials
What to take
• Clothing: should be lightweight but not white or gaudy - drawing attention to yourself isn't the best plan for approaching nervy animals at close range. Long sleeves and trousers are better than shorts and T-shirts for staving off mosquitoes; at higher altitudes warm clothing is vital.
• Binoculars: You'll be lost without a pair - preferably a lightweight, compact pair. A camera is a necessity, too, though the sights are so stunning that even a cheap holiday-snap model will produce breathtaking pictures.
• Insect repellent: Except for children, repellent containing a small proportion of the chemical Deet is still recommended, though citronella oil (available cheaply from pharmacists) is a good supplement. A course of malaria treatment is essential - see your doctor around a month before departure if possible.
• Yellow fever certificate: Required by all visitors; your GP will either arrange for a jab or give you a certificate to show you're exempt.
• Mosquito net: provided by most lodges but worth taking, especially if you're travelling on a budget and staying in cheaper accommodation.
• Inflatable cushion: Tanzania's roads have to be experienced to be believed; it's worth taking something to cushion the blows.
When to go
Peak season is from June to October, after the long rains, before the short rains and while the temperature is relatively cool. December to March is hotter; April and May, the rainy season, is the cheapest but many roads may be inaccessible. You can save by going in late May or early June, when the rains have stopped and the migration is in progress, but low-season prices still apply at many lodges.
The practicals
British Airways Holidays (0870 2424245) offers a seven-night safari in Manyara, Ngorongoro, Serengeti and Kenya's Amboseli plains from £1,329 per person, including flights to and from Nairobi, transfers, game drives and accommodation and meals in Serena properties, but excluding tax.
Optional beach extensions in Mombasa, Zanzibar, Mauritius, Mnemba or Lamu. Serena Hotels' Nairobi head office, tel: +0025 4271 0511; e-mail 62578620@eln.attmail.com. Motor safaris (in all three areas) were with Warner Safaris, based in Arusha, on 00255574580/1.
