Most of yesterday I was campaigning and lobbying for a saner world. At the same time I was contemplating vistas and creatures of timeless perfection. I was simultaneously doing my bit for biodiversity and revelling in some of the finest wild wonders that the planet can offer.

On the one hand, I was standing up against the madness of biofuels: the demented rush to destroy rainforest and other important places in order to grow crops to burn for fuel: an insane and destructive cycle that hastens habitat destruction without slowing down climate change.

And on the other hand I was gazing out across the reedbeds of Suffolk watching a male marsh harrier, perhaps the most handsome bird alive. He was savouring the advancing spring in every nuance of his body language, gliding at belly-tickling height over the seedheads and then swerving dramatically up to a hundred feet and more.

While this went on, I was campaigning for sense on rising sea levels, concerned about the effect on bitterns, birds that mostly live in marshes just inland. If the sea takes over the marsh, the bitterns will not be able to cope.

At the same time, I was greeting the lapwings who were beginning a springtime campaign of silly flights. As John Cleese did silly walks, so lapwings fly in the spring: zooming, wig-wagging, swooping. As the sun came out, bird after bird made a sketch of silliness. The year is turning, and the blood in the lapwings' veins is just beginning to fizz.

But I was also keeping a round-the-clock watch on hen harriers, the most persecuted birds in the country, illegally destroyed by shooting interests; you may remember the scandal of the hen harrier shot at Sandringham last year. Hen harriers have it tougher than most, but I was doing my best to help.

That didn't stop me from hearing the soft grunt of a bittern in the reeds: not ready yet to start his full boom, but he too was preparing to rip. Spring was fizzing in front of me like a firework lit, but not yet gone off. Light the green touch paper and stand well back. Cetti's warblers shouted at me from almost every turn: they were an exoticism here less than 20 years ago.

But these matters didn't stop me from supporting the discovery of Beck's petrel, a bird not seen for almost 80 years. An expedition to the seas northwest of Papua New Guinea discovered a flock of 30 of them: and it was all my doing.

And as the male marsh harrier sank into the reeds I caught a glimpse of disturbance just below where I was sitting. Stoat! The seldom-seen creature was out in the open, running in his ferrety way across the bank, long and lean, black-tipped tail a-twitch, up to no good, I'll be bound. Stoats are persecuted in much of their range by the pheasant-rearing tendency: not here. This is a place where you are always going to encounter some kind of wonder.

I am able to do all these splendid things at the same time because I am a member of the RSPB. I was visiting Minsmere, one of the RSPB's 200-odd nature reserves. The organisation represents more than a million members, and it is a major, sober, sensible, fully baked campaigner and lobbyer for all big conservation issues. At the same time, it owns fabulous places that are jumping with flying and singing wonders. I am part of all of that: and that strikes me as a pretty good deal.

See The Times's new nature and travel site in assocation with the RSPB: www.timesonline.co.uk/lovenature

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