A legend in the field of nature documentaries, Sir David Attenborough is back on American television with a new series called "Planet Earth: Blue Planet Two." After all these years, you might say Attenborough is a force of nature all by himself, as our Mark Phillips discovered:

The makers of the best wildlife documentaries learned long ago that it takes more than just pretty pictures of animals to grab an audience. The animals have to have a story.

"Planet Earth: Blue Planet II," the latest BBC America nature series -- four years in the making -- has hit U.S. TV on BBC America, featuring, for example, bottlenose dolphins, which narrator Sir David Attenborough tells us, "They are extremely intelligent, and with this intelligence comes playfulness. They surf! And as far as we can tell, they do so for the sheer joy of it."

Surf's up! (For bottlenose dolphins, that is.) From "Planet Earth: Blue Planet II." BBC America

As far as we can tell, the formula of new science, new technology and a familiar old face has brought its own form of sheer joy.

The series is hosted and narrated by the now 91-year-old Attenborough, the British naturalist who just about invented this line of work, and who has seen it change.

"Audiences wanted -- or were perceived by network controllers to want -- something that was always cuddly or something that was not too serious," he told Phillips. "But that's changed."

Sir David Attenborough with a tortoise. BBC America

In the old days (his first major series ran in 1979), if the audience wanted cuddly, Attenborough gave it to them, such as the cuddling gorillas.

Back then, the shows had a kind of playful innocence to them. Pity the famously slow-moving sloth when Attenborough and his crew showed up.

Phillips asked, "What you can do with them -- has that changed over time because of what we've learned?"

"Well, we have become more and more sensitive about not influencing their behavior," Attenborough replied. "And the audience has become more and more demanding, that they should see it as it is. They aren't just interested in pretty pictures and move on. They want to know about it."

And the IT has changed. Wildlife survival is increasingly about trying to survive us.

"There are now worrying signs that conditions in the oceans that have remained relatively stable for millennia are changing radically," Attenborough said.

Nowhere is the change being felt more than in the polar regions. And the series has had to invent new technology to capture it.

Executive producer James Honeyborne and his team mounted a camera in a glass dome to show just how precarious life now is for a mother walrus trying to find a piece of ever-diminishing sea ice on which her new pup can rest and feed.

A specially-designed camera apparatus shows life for a walrus and her pup above and below the water's surface. BBC America

"It gives a great context for that animal," said Honeyborne. "You begin to understand what it is to be a mother walrus in this world."

Phillips said, "There seems to be more of an editorial bent to what you're saying -- a little bit more finger-waving content because of the issues that we all know are underway now."

"And that's true, and the reason that it's true is there wasn't the urgent need that there is now for a bit of finger-wagging," Attenbrorough replied. "In the service of trying to tell the truth, when you see what's happening -- like for example, plastic in the oceans -- if you don't actually represent that, you are distorting what the reality is."

That reality expands each time one of these series hits the air: Some type of previously-unfilmed or newly-discovered animal behavior, like the giant trevally fish that leaps out of the water to snag birds in mid-air … the tuskfish that's so clever it uses tools, bringing clams back to its "kitchen" to smash them open … and the submarine that can follow two-meter-long squid down 3,000 feet

Producer Orla Doherty saw what happens when squid run out of fish: "What took our breath away, as happens so many times in the deep ocean, was when this happened -- when they don't have fish to feed on, they feed on each other. This has never actually been filmed before in the deep, and this whole tug-of-war played out right in front of us."

Cannibalistic giant squid, from "Planet Earth: Blue Planet II." BBC America

Attenborough said of the series, "It's beautiful. It's surprising. It's not trying to sell you anything. It's not wanting your vote."

"You're also saying, 'And we're wrecking it, we're losing it,'" said Phillips.

"We are, but that follows off the first bit. I don't think 'That's an interesting program' because I think we have a moral duty to do so. Those are the sort of television programs I like! And happily, there are an awful lot of people [who] feel the same. But those kind of people, because they feel the same, also want to be told it straight."

Which is what Sir David does.

As he intones in the series, "Surely we have a responsibility to care for our blue planet. The future of humanity -- and indeed all life on Earth -- now depends on us."

Watch a trailer for "Planet Earth: Blue Planet II":



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