At the southern tip of Normandy lies the Parc Naturel du Perche. A picturesque patchwork of French countryside, seamed by winding streams and ramblers' footpaths, quilted with extensive forests and dotted with farms and orchards. Known for its tall Norman barns, local cider, and the sturdy Percheron draft horses used to pull heavy loads, it is a bucolic setting very different from the savannahs of Kenya that I am used to.

Yet here I am,

in the middle of the Perche, and less than ten metres away is an adult lion. He's about four years old, with a thick blonde mane and a nose that is still a youthful pale pink. And he is lying like a sphinx, with his head up, looking at me.

How many times have I seen a lion lie like this before, in the shade of a tree gazing out lazily over the plains? Or, waiting expectantly as a lioness approaches to rub faces with him, in that wonderful tactile way lions greet each other? Or, closing his eyes in paternal indulgence, while his small cubs clamber over his hindquarters and pounce on the tassel of his tail, as his upper lip twitches into a gentle sneer?

The pupils dilate, and the gaze becomes 100% focused - and suddenly I have felt what it might be like to be a wildebeest coming face to face with his nemesis.

But this lion's eyes barely flicker as I approach him. There is no gleam of interest, no unwavering intent, no spark of fun. Usually, for any cat, a moving target is always going to be fun to chase - whether it ends in a meal or not.

He is not even wary of me, as any self-respecting lion in Africa has learned to be, when a human approaches on foot. This animal is weary, dispirited, and - something I have never seen before - he is bored.

I had been driving to the local market town when I noticed the circus. Across a busy road, a McDonalds, a car wash and a DIY centre face a sprawling disused supermarket allotment. But today, a huge candy-striped Big Top, and a semi-circle of trailers are ranged around the car park of the abandoned store.

Some of the trailers have barred sides and I glimpse the familiar form of a lion standing in one of the cages. Then I notice the roadside posters - on street lamp, bus shelters and litterbins.

Beneath the headline "Visit the Zoo", white tigers and lions leap through rings of fire, or pose majestically for their portraits. I read that the circus will be in town for five days. I park, cross the road and approach the circus.

A man is uncoupling a trailer from a truck and I ask if I can walk around. Squinting at me through a curl of blue smoke from the cigarette clamped between his lips, he nods.

Four shaggy Bactrian camels stand in a roped-off area of tarmac. No grass, no trees. Just white lines where shoppers once parked and a single lamppost casting a narrow shadow - below which, pitiably, the camels have congregated.

Beyond is another trailer with more lions and tigers in it - yes, there are white ones there. The two-by-12-metre carriage, partitioned into stalls, holds at least six big cats. Some sleep, others sit or stand up, staring out at passing traffic and pedestrians, with dull eyes.

The UK government recently announced that a ban prohibiting the use of wild animals in circuses in Britain would come into effect in 2015.

How many big cats, elephants and other animals watch the world through the bars of cages, without ever having known the infinity of wilderness? Knowing, instead, the blurred scenery of tarred roads, as they travel in gaudy procession from town to town.

The frightening, flickering flames of fire as they leap, night after night, through burning rings, or dance or perform headstands, to the crack of whips and the clamour of applause.