Mammals viewers want sperm whale footage to win all the awards

What did you miss?

Once again, Sir David Attenborough is illustrating the beauty of the natural world with a glossy documentary series in Mammals — and this time the focus was on the water. The new episode cast an eye below the ocean surface and, in particular, it was remarkable footage of sperm whales that caught the attention of viewers.

While seasoned Attenborough viewers are accustomed to seeing orcas on the attack, there was something very special indeed about the first scene of the episode. It followed a camera crew exploring the deep ocean, a mile underwater, only to be stunned by the surprising appearance of a sperm whale.

Who, what and why?

Viewers could hear the crew within the deep sea vessel as they explained how stunned they were to see a sperm whale at such depths. In his narration, Attenborough described just how significant this was.

"Like all mammals, sperm whales breathe air," he said. "Yet, almost a mile underwater in the freezing darkness, they seem completely at home. They, like many mammals, have overcome the challenges of living in water in the most remarkable of ways."

Later in the show, we got a further glimpse into the hunting strategies of the sperm whale. Sleeping for just 7% of the time, they are able to dive into the deep ocean and remain underwater for an hour before they need to emerge for breath.

It's fair to say this deep sea filming at both ends of the programme was a hit with viewers, who immediately applauded the boundary-pushing work of the crew.

Attenborough explained that the whales' bodies have evolved in such a way that they are able to hunt giant squid well below the depths any other mammal would be able to reach.

He said: "As they descend, their bodies change in an astonishing way. The increasing pressure squeezes their lungs until they collapse completely. To save oxygen, their digestion, kidney and liver shut down."

Attenborough's voice-over explored the ways in which these animals have learned to thrive in their unique world. But he also explained that man-made threats like fishing debris are threatening the continued existence of these creatures. As ever, Attenborough made us think about what we can do to protect the natural world.

What else happened on Mammals?

Mammals explored the lives of a huge number of aquatic mammals, including the strange-looking star-nosed mole and the seashore scavenging of coyotes in Mexico. We also learned how bottlenose dolphins make muddy circles of disturbed water to encourage fish to simply jump into their mouths.

In perhaps the most shocking sequence of the episode, viewers could only watch as a pod of fiercely intelligent orcas were able to separate an unfortunate humpback whale calf from its mother.

Mammals continues on Sundays at 7pm on BBC One.

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Watch: Trailer for BBC series Mammals