Bonham now has his own camp and concession on the North bank of the Rufiji - a small (just six cottages) and very up market camp called Sand Rivers perched overlooking the Rufiji river so that you wake to the sounds of snorting hippos, the cry of the fish eagle, the bark of African wild dogs and the harsh racket of the hadeda ibis.

You can fly straight into Sand River's own little airstrip from Dar-es-Salaam or you could do what we did, which is to ease your way in gently, divesting yourself of metropolitan angst by degrees, by stopping off first at a charming tented camp called Mbuyini. It sits on a little promontory on a bend in the river and you can spend happy days tootling up and down the river learning to tell the grey heron from its black-headed near relation, picnicking beside the lakes fringed by Borassus palm trees and tracking the local pack of hunting dogs.

Then, if you are very very fortunate, Bonham himself turns up to take you up-river by boat, drifting past the nesting storks and hippo pods, arriving in old-fashioned style at the wooden landing-stage of Sand River.

At Sand River you go on game drives through the 15 or so square miles of Bonham's private concession or you walk with a well-trained guide through the bush or you go on jaunts up the river sure of seeing hippo, crocodile, waterbuck and buffalo and hoping for a sighting of the rare Rock Pratincole or the even rarer leopard.

But, above all, you get the chance to sleep out on the sand river bank in a little mosquito net. We spent a magical 24 hours walking with Bonham and a game scout for miles along the sand river which we had entirely to ourselves.

We went to sleep watching packs of hyena coming to feast on the bones of a dead buffalo by the light of the full moon and listening to that spine-chilling noise of the lion roaring in the distance.

At dawn we breakfasted on scrambled eggs and bacon and then set off to walk back to base, climbing up small hills for better views, sometimes resting quietly beside lakes decorated with drowned palm trees, watching a Goliath heron balancing precariously on the back of a hippo and flocks of open-billed stork circling high in the sky.

All this is just a taster for the real treat, the thing that makes Bonham's outfit special, which is his long portered walks into the Southern Selous. The Selous north of the Rufiji is wild by most people's standards - it has just six lodges (of which Mbuyini and Sands River are much the best) together catering for no more than 100 people at a time.

But that is crowded compared with the Selous south of the Rufiji. This is serious wilderness country, the country that Peter Matthieson, Tom Arnold and a very young Bonham explored 16 years ago on what they dubbed the "last real safari" (and which Peter Matthieson wrote about in Sand River). Here there are no lodges at all - just a few temporary tented camps in the hunting blocks and Bonham's occasional mobile camps.