Over-achievers in the undergrowth

The silence of Lenny Henry is one of the miracles of nature. It's a phenomenon so rare that a BBC camera team had to journey deep into the heart of the Amazon jungle to track it down. Henricius leonardus is a relatively common breed: if you sit still at your viewing post on the sofa for long enough, sightings will be frequent and spectacularly various. The species is often seen wearing a chef's hat, or a red nose; it'll be found befriending the homeless, or presenting the Baftas. Adept at disguise - priapic crooners, hairy botanists, matey cockneys - the Henry has a bewildering variety of calls: whoops, squeals, screams and growls. Somewhere between a magpie and a chameleon, it doesn't seem to have any noises of its own: they're all borrowed, imitated, adopted as camouflage.

The moment Lenny Henry ran out of voices was captured in Lenny's Big Amazon Adventure (BBC1, Mon). He had to build a support structure for his own hammock after the cords wrapped round trees at each end buckled under his weight. Boy, did that shut him up!

The programme belongs to a new genre designed to test the mettle of performers whose lives are deemed to be too cushy. Comedians are the new renaissance men (and women): they write all the hits in the West End, the fiction best-seller lists and the pop charts, and they get to front all the big documentaries. Occasionally, they even find time to make comedy shows. They are very rich, doubly so if married, as they usually are, to each other (Mrs Henry is the Vicar of Dibley).

So the thinking is simple: if comedians really are taking over the planet, let's see them conquer the less habitable bits of it. They can take along an SAS jungle expert, but they'll have to make do without a script.

The subtext is plain: you want to see them cock up their own survival, or at least suffer a little. That's why Henry's silence was golden. It was the closest he got to not coping. (The rest of the time he was very funny.) Between the jokes, there was a lot of "What am I doing here?" And yet even when abandoned at night with only a camcorder for company, a man with so many voices could never be truly alone. As is commonly said of Peter Sellers and his library of accents, the real man probably wasn't even there at all.

More comedy in Drovers' Gold (BBC1, Fri), also unscripted. The hot new genre in BBC drama seems to be the western, but a cheap version with Celtic accents located somewhere in the British Isles. See also Plotlands (BBC1, Sun). Drovers' Gold, a blockbuster about cattle set in Wales, has the same production values as Rhodes: lots of horseback machismo, fulminating landscape, only rather less damage from ultra-violet rays.

These are good times for Welsh actors - thanks not least to Ruth Caleb of BBC Wales, who is producer here - but this drama about the bad times for Welsh farmers is not the best shop window for their excellence. Its cast of hard-up rural philosophers speak in half-formed epigrams. "Not an easy thing, the present," goes one of them. Oh boyo. It's all about a family of tenant farmers who can't afford the rent. They try to flog their herd, but no one will pay enough. "We cannot live on such a price," says young Aaron.

Nor, it appears, can the series itself. While an evicted tenant is hanging himself outside, the wicked English landlord is hosting a lavish dinner party that the budget cannot afford to show you. Instead, as the man prepares his noose, the edit cuts away to an inexpensive but dramatically irrelevant scene of his fellow tenants listening to music in a barn. You dread to think what London will look like when Aaron's drove gets there. About as teeming as Lenny Henry's bit of the jungle.

One day in the near future Harry Hill (C4, Fri) will doubtless get his own survival documentary. Might I suggest the middle of the Sahara desert? Or one of the more remote valleys of the Himalayas? And he can take his family and his sack of pendulously surreal gags with him. But no survival expert, and certainly no camera crew. Now that I've said that, he'll probably win an award. And Lenny Henry, safely back at the Baftas, will present it to him.