They are sitting in a tent in the Amazon basin when a scuffling, nibbling noise begins. Not to worry, he says, just a paca, chewing away at the guy-rope. Now, your paca is a creature like a large guinea-pig, not very bright, which lives by this rule: bite it, and if it doesn't bite back, carry on. That's nice, but should they really just sit there until the tent falls down? Oh well, perhaps they'd better shoo it away.

So they did. Joanna Pinnock was doing her best not to Cry in the Dark (R4). She'd already been told how to extract a burrowing tick from her person and now, suddenly, there was a horrible kind of strangled, roaring burp. "Erm, 'scuse me?" said her companion, Adrian Barnett, smooth and cool as a Greek yoghurt. Not to worry (again), just a pottoo on a post: your pottoo is a bird, rather like a vast scruffy night-jar, with its huge mouth agape for a passing gnat.

She's a plucky girl, Joanna. All summer, she's been braving the Twilight (R4), dodging bats, moths and foraging hedgehogs in England, but this was a bit much. The next blood-curdling sound proved to be a cow, protestingly providing provender for a vampire bat. Scared? Oh no, said Adrian, they're lovely friendly things, vampire bats. In Latin, they sounded like Desmondus rotundus (round Desmond? Anything to do with the naked ape Mr Morris?). Their fat little bellies are full of blood, which they generously regurgitate for less successful friends. Joanna, he observed solicitously, was looking very pale.

The really nice thing about Joanna Pinnock is that she reacts just as we would - or as I would, anyway. She probably knows more than most of us about Nature Study, but when a relation of the jaguar called, apparently, a "margot" (or could it be, fond hope, a Margaux?), with extended balletic legs, comes prowling for prey, she knows she's beat. She zips up the tent, switches off her recorder and, one imagines, hopes she'll make it home.

Home for Ivan Drever is Orkney. He was born there and still derives the inspiration for much of the music for his band Wolfstone from the savage, beautiful landscape of those Isles Ne'er Forgotten (R2). Revisiting the place, he took us to Longhope, to meet the poor chap who bore the responsibility for sending out the lifeboat on a wild night in March 1969. All eight men were drowned, a frightful tragedy for such a tiny community. He remembered that there had been three weeks of gales, and the sea was terrific: "the boat was just completely overwhelemed", he said, giving the word four syllables and its full, terrible meaning. "Brave Souls" was Drever's lament for the men: its plangent harmonica echoing the screaming gulls was enough to make you weep.

Drever was precisely the right person to make such a programme, which was more than you could say for the one that preceded it - I wonder whose bright idea it was to ask Loyd Grossman to narrate Simple Gifts (R2). It didn't work. The viscous urban sprawl of his delivery engulfed the primitive, Calvinist fundamentalism of the Shakers in an uncomfortable, semi- cynical, quasi-scholarly slick.

Their music is simple, mildly affecting stuff - often derived from birdsong, if you are to believe the legends. There are extant, drawled Grossman, over 1,000 sawngs, "pleasing to the ear and high on piety". They believe carnal relations are the cause of the world's problems, so we are not to be surprised that there are only eight of them left. Professionals now perform their songs and their simple furniture is immensely fashionable, as is - a glimmer of enthusiasm here - their wholesome, rural food. There was some interesting history to be dug out of all this, but it was only glimpsed. "Oh brethren, ain't ye happy?" sang the Boston Camerata, slickly. Well, possibly.

The World Service has been examining world religions and has reached The Way of the Buddha. The name Buddha means "the fully enlightened one", and the current holder of the title, Gautama, lived about 2,500 years ago. He started out as a wealthy prince, then renounced splendour and nearly starved until he realised that the secret of happiness is the middle way. This Buddha was not divine, but an exemplar of moral perfection. Most encouragingly, he had to work at becoming all- loving, compassionate, wise and understanding, but he got there. Theoretically, we could all become Buddhas.

This was the first of what promises to be a fascinating series, well- researched and logically presented. Though I wouldn't want to be frivolous about it, the information it provided included a definition of samsara: it means the cycle of death and rebirth. And I thought it was a perfume.

The quest for enlightenment continued in The Mic, the Star and the Crescent: Rappin' for Islam (Rl), Phil Pegum's documentary about the connection between hip hop music and black Muslims. Briefly, it is a very strong link, but also very factious, and very, very complicated. Harry Allen, self-styled hip hop activist and media assassin, narrated enthusiastically, if confusingly. Probably only a few dedicated rap fans realise the religious affiliation of their heroes. One disturbing fact emerged: the Five Per- Centers hold that only five per cent of the population are enlightened. Their spokesman was the charmingly named Wise Intelligent, of the Poor Righteous Teachers, who announced emphatically that mathematics is the language of the most high. My search for enlightenment petered out, despairingly, in the dark.