Broadcaster Sir David Attenborough has said that he is saddened by the lack of choice on today's TV screens.

The naturalist, 88, is presenting a six-part wildlife series, Life Story, for BBC1 and will later return to the channel to front a 3D film on the Great Barrier Reef.

But the former BBC2 controller said that he did not know what to make of his old channel, because it was hard to see what distinguished its programmes from shows on BBC1.

Sir David told Radio Times magazine that while the number of channels had exploded in recent years, they were all chasing certain genres, such as cookery and lifestyle.

"The sad thing is that you'd think that the more stations there are, the more varied the output, but the practice is the reverse - the more you get, the more similar they become. And you get genres that become the flavour of the month," he said.

"I don't watch any cookery programmes, whether they are competitive, whether it's the Great Bake Off, or... I don't watch quizzes either.

"I mean, they're perfectly OK - I'm not being snobbish about them - but I've quite a lot to do and I don't put on the television as a sort of 'filler'.

"I've got quite enough to fill my life, and so I only put on programmes that I actually, positively, want to see."

The wildlife presenter added: "I don't watch serials. I'm sure they're perfectly enjoyable, and I've got nothing against them, but I just don't do it."

Pointing to the holes in the schedules, he said: "There are a great number of subjects that aren't covered. I mean, music is not covered in any other way than a performance, really."

He complained: "There's no serious programme about natural history on a regular basis.

"I'm a great one for regular programmes that I can make dates with. I like scientific programmes; Horizon is a great series. I wish it was a regular series so that I could say, 'Yes - first Thursday of the month... I always watch Horizon'."

He said that he was unhappy with the short length of the series on today's TV screens.

"Life On Earth [which Sir David presented] was 13 one-hour parts, weekly. Civilisation was the same.

"Now, people talk about a 'two-part series'. I mean, for God's sake! You know? And even in a 13-part series... you couldn't deal with something properly but you are paying respect to the viewers' interest.

"If you're going to stick with us, stick with us for three months, and at the end of it you'll have learnt something. There was The Great War on BBC2 - that was a 26-part series. Come to that, The Forsyte Saga was a 26-part series too.

"These days it's a three-parter if you're lucky, or it's a two-part series. I would like a stronger commitment and a belief in your subject."

Asked what he made of BBC2 today, Sir David said: "I'm not sure how they would define its policy. I would be seriously interested to know, in a paragraph, not necessarily a sentence, what guides them, what guides the editorial decisions on BBC2, because it isn't overly plain to me.

"I guess that BBC4 has taken on perhaps the invention and experimental side of BBC2, but it wouldn't harm them to say so. You know, if they said, 'That's what we're going to do.' But they don't actually say it."

He added: "I can't tell whether a programme is on BBC1 or BBC2 just by watching it."

BBC director-general Tony Hall announced earlier this year that the corporation would bring back Civilisation, the programme that Sir David commissioned when he ran BBC2.

Asked whether he was looking forward to seeing the new version, Sir David replied: "Yes, but it's a hell of a job.

"The mood of the audience - or maybe it's the controllers - is against the expert. The general view is that viewers don't like people coming along and saying they know more about it than you do, so it's unfashionable.

"People criticised (art historian) Kenneth Clark's mandarin vocabulary in Civilisation - and it was - but it was wonderful to listen to! There are people who know more about it than you do, and I like that. I enjoy being told."

He said that the new version of Civilisation also needed an expert to present it and asked to give a name he praised MP and historian Rory Stewart for his programme about Hadrian's Wall, saying: "He knew the subject because it was in his blood and because he was fascinated by it. That's the sort of person you want to watch."

He said of the commissioning process: "The trouble is, the BBC falls over backwards with all kinds of committees and surveys to make sure that (it) is as fair as it can possibly be, but the consequence is it moves at an elephantine pace."

Sir David said of his programme on the Great Barrier Reef: "It's the first 3D film I've made for them because the BBC hasn't really gone into 3D - indeed they said they weren't going to - but there's been a change."