Environmentally friendly and forthright presenter of Bellamy Rides Again who would like to be a graceful but tough birch tree. Big cuddly green and adventurous giant who has broken nearly every bone in his body and has a ballet company.

Clever and funny honorary Maori-cum-conservationist who spent 24 days at home last year with a menagerie, his child, four adopted ethnic ones and a wife. Affable and ebullient millionaire naturalist who once went to jail in Tasmania and has written 44 books.

Enter David Bellamy.

He’s foregone his habitual T-shirt and shorts in favour of casual mountaineering gear suitable for the Piccadilly clime. ‘I have 27 pairs of these trousers,’ he says, waving his arms at the garb he’s worn from the North Pole to the tropics. He wears Cornish pastie shoes on his feet. ‘I suppose my clothes show that I’m a pretty sloppy person really,’ he booms, in the voice of a nasal East Ender crossed with an animated cave man. ‘I don’t like wearing suits. I turned up like this at a lunch at the Park Lane Hotel at which I was the guest of honour – and they wouldn’t let me in!’ He laughs. ‘I wanted all girl children so that I could buy them wonderful dresses. So perhaps,’ – hopeful tone – ‘I should’ve been a girl.’ He talks as if he’s imitating himself – and doesn’t, he says, do it as well as Lenny Henry. He speaks to plants in the same way. ‘Just as I talk to people. I say things like, ‘You’re a hairy one for your sort of species’.’ The model for the caricature laughs.

And how would the bewhiskered botanist with the famous broken nose describe himself physically? ‘A moderate wreck,’ says the buffoon who doesn’t have one undamaged vertebrae in his neck.

Does he think he’s intimidating? He’s 6ft 2in with a rugby-toughened frame. ‘Not verbally – but physically, perhaps. Imagine, I have to look at it every morning – that’s why I don’t shave!’ He’s expressive with his body, using it (he later says) as an instrument of music.

And does he think he’s good looking? ‘Sorry!’ (surprised tone). ‘No. But recently I’ve found myself combing my hair before speaking to camera – which is awful. I never used to carry a comb. I’m getting vain in my old age.’ He later alludes to himself as the ‘ugly face other people use to save the world’. Does he think he’s ugly? He looks taken aback. ‘What is ugly? A wart hog is the most beautiful thing to a lady wart hog. And I really don’t think what somebody looks like is important.’

So ask him how he would change his looks. ‘I’d use all my muscles. I went to Pineapple Dance Studio and did a cardiac funk which almost killed me. I wanted to be a ballet dancer until I grew this big.’

I say, jovially, I can’t quite imagine this beefy bloke in a tutu, ho ho. David Bellamy as you’ve never seen him before, ha ha. ‘Males don’t wear tutus – though I have worn them many times at college dances. Do not mock – if there’s one thing I don’t like, it’s mocking. Mock me as much as you like – but don’t mock ballet, it’s far too important.’

He says he’s ‘58 heading for 60′. And what does age mean to him? ‘Desperate. I hate being old. I don’t want my end to be tranquil and wonderful – I want to go out with a bloody great bang. If ever I get to the stage when I cannot do all the things I want to do, I’m going to chuck myself off the Himalayas. I know exactly the place.’

He comes over, however, with an infectious enthusiasm, charm and immense energy. He is excitable, with a dry wit and greatly likeable. He is also clearly a sensitive, shy man who suffers from self doubt.

So how would he describe himself? ‘Oooh, I don’t know. What a terrible question! Bloody minded,’ he says, in a thudding way. He then talks slowly, with lengthy pauses. ‘Abrasive but not misguided. I think I’m 99.99 per cent honest. I try too hard sometimes – because the world’s in a bloody mess. Also I’m a baby sometimes, ‘cos I don’t like being kicked by my own side . . . I’m a big softie. I’m the Andrex toilet paper that isn’t really made from sustainable sources!’

And what does he particularly like about himself? ‘Nothing very much’ (long hesitation) ‘but I’m like a little terrier who stays in with his teeth as long as he can – that’s why I’m not retiring.’ And is he happy? ‘Yes, I enjoy everything I do – and if I didn’t, I’d stop doing it.’ He has one helluva impact. What sort of effect does he think he has on people? ‘I’m overpowering if I’m talking about environmental matters or ballet. If they’re talking about anything else, I simply opt out. I can just go to sleep and wake up in five minutes.’

He’s doing live television in front of me – without the cameras. But what’s the difference between his public and private persona? I don’t imagine he talks to his children in this way. ‘I do. I was told ‘when you’re at home be Dad and not David Bellamy’ – unfortunately it’s one and the same thing. I can’t switch it off.’ He says he first turned it on aged 21. So who were you before that? ‘A dispossessed ballet dancer.’

He’s also a workaholic who puts in an 18-hour day. ‘I really find doing nothing very boring.’ He feels such a sense of urgency because he reckoned he was a drop-out at school and that he let his parents down badly. ‘So when I finally got switched on, I’ve been working ever since.’

Such behaviour might indicate a low self-esteem. Certainly there’s a sense that he doesn’t feel he measures up. ‘Yes, it’s very low. I don’t think I’ve lived the sort of ethical life my parents did . . . I’m a worm. But worms are useful – they make soil.’

He talks loudly and blames it on genes. Is he actually shy? ‘Yuh. I still hate using the telephone and I won’t go into shops. The media has done a lot of good for me because I can step out of my shyness and Be David Bellamy, the telly personality. But sometimes I just want to crawl away and disappear.’

Is he intrepid? ‘Yes. I will go anywhere in the world as long as it’s not with nasty people. I’d rather go swimming with Jaws than come up against people.’

So how does he see himself sexually? How does he rate himself as a man? ‘I was immensely lucky. I met someone who could put up with me – with my workaholism, overt shouting and bigoted self opinionism. I found a really beautiful person who wanted to marry me. So I didn’t have to wave myself about all that much.

‘When I was a youngster, the only time you were going to get it was when you got married. Whatever anybody says, sex within a marriage – and I don’t know anything about it outside married life – gets better and better. Not as often – but by God it gets better.’

So what makes him tick? ‘Mars bars.’