'Rhino, in de grass, wid de horn!'
That was my guide, George, and I hoped he was referring to the horn on the rhino's nose. I had never considered rhinos to be particularly well camouflaged, but as George became more and more agitated in the driver's seat, I strained my eyes to see the creature amongst the wavy yellow stems.

'You see 'im. Dere is a mother, a father and a baby. Man, they so ugly.' George was a taxi driver who had picked me up in Nairobi, and he had somehow managed to talk me into letting him act as my safari guide for the afternoon. He had insisted that he would show me 'all de animals,' and so far he wasn't doing a bad job.

I still couldn't see the rhino, though, and I began to wonder if he was hallucinating. After all, his animal identification skills were limited, everything vaguely antelope-like was termed 'gazelle', and anything resembling a monkey was labelled 'baboon'. For all I knew he could have been looking at a family of tortoises or something, and assuming that they were rhinos.

As I watched intently, I suddenly saw movement. George was clamping his fists to his nose and excitedly making trumpeting noises, as the male ambled out into the open.

'You' see 'im now? He use de horn to kill food.'

This was another of George's unique insights into the animal kingdom of southern Africa. He was making it up as he went along, but it all served to make things interesting.

Following the huge bull came the slightly smaller female, and then the sprightly youngster, skipping along and chasing a terrified butterfly. Why it didn't just fly a bit higher, I'll never know.

'Get a photo. Show your friends,' George insisted, taking the words out of my mouth. Tentatively, I leant out of the window of our ageing Peugeot taxi. Rust fell to the floor in orange flakes as I positioned my arms on the door and raised the camera to my eyes. Through the lens I saw the expression on the face of the bull change from contentment, to curiosity, to furious anger.

'Uh-ho, 'im not 'appy,' George said, with impressive understatement. Before I knew it, the rhino's head was bowed and he was charging. George tried frantically to restart the engine and I placed my head between my legs, bracing myself for impact in the way they show us all on an aircraft safety drill card. I was convinced that the papier-mché taxi would be crushed by the rampaging four-ton beast.

Just in time, the engine started with a splutter. George accelerated away from the crazed animal, leaving me with minor whiplash injuries and a rather closer view of a fibrous rhino horn than I would have liked. Still in shock, I watched the angry rhino contemplating our escape via the taxi's rear-view mirror.

'You wanna go back and get your photo?' George inquired, concerned that I had missed out.

'I'll buy a postcard,' I managed to stammer.

Paul Smith, 23, from Liverpool, is taking a masters degree in zoology at Southampton University