David Attenborough's Frozen Planet: Spring Arrives At The Poles In Episode Two

David Attenborough's dulcet tones returned on Wednesday night to continue sharing the harsh and humbling lessons about nature's fierce pecking order.

Episode Two of Frozen Planet, BBC One's epic seven-part nature series, saw the arrival of spring to the poles.

Spring may be a time for new life (wolf pups, penguin chicks and polar bear cubs) but it's also a time of violent storms and 150mph winds. As Attenborough showed last night, it can be a deadly season in the polar extremes.

In an amusing sequence we saw tens of thousands of male Adelie penguins waddling back to Antarctica to build nests and await their mates. With nothing but stones available, the competition proved hilariously fierce. "Some penguins turn to a life of crime," warned Attenborough, as we watched a cheeky penguin steal another one’s stones.

Is there an animal cuter than a polar bear cub? Watching the little scamps larking about in the snow, it felt hard to believe. But Attenborough didn't allow cooing for long. Bringing us back to reality, the veteran presenter reminded us that the mother "must catch a hunt soon, or the whole family will starve".

In other stories, we were shown the purpose of the narwhal's "unicorn" tusk, followed by some amazing footage of the freakish-looking woolly bear caterpillar's 14-year life cycle - not forgetting an influx of new life to the tundra, and some marvellous scenes of penguin courtship.

Finally, as killer whales swam onto the scene, penguins leapt out of the sea like torpedoes in a panic-stricken race for survival, and we had to worry about the penguin left behind, stranded on a block of floating ice, surrounded by killer whales.

Attenborough is a master of suspense, only telling us at the end that the penguin had no need "to be alarmed" as "these killer whales are the types that only eat fish".

SLIDESHOW: See pictures from Frozen Planet episode two below...