Last Night's Viewing: Frozen Planet, BBC1 / Paul Merton's Adventures, Channel 5

I guess pretty much everyone's been through a tough patch in the dating game – moments when you wondered whether you'd ever meet up with a suitable partner. Spare a thought for the polar bear, though, obliged by nature and the unforgiving mathematics of the predator pyramid to roam for hundreds of square miles in search of a mate. What's more, both the mate and the miles are blinding white. In Frozen Planet last night, we were able to watch one bear doggedly pursuing another by literally following in her footsteps, placing each paw on to the compacted snow left by his target, in order to conserve energy. And it wasn't foreplay he was saving the energy up for but defence of his prize. When their brief liaison began, the male looked like something off a global warming poster, a Brad Pitt of polar bears. By the end, having had to break off repeatedly to punch interlopers who were eyeing up his date, he looked more like Sylvester Stallone at the end of Rocky.

Not many people have seen polar bears mating, and I'm not sure we did here either, given the brevity of the embrace we saw. It was almost heartening really, the thought that there might be something out there that the Natural History Unit hadn't been able to film. Then again, the results are so amazing when they do succeed that you wouldn't really want to limit their triumphs. If, like me, you felt a moment of doubt at the beginning of last night's episode ("Haven't penguins and killer whales been done countless times before?"), I can't imagine it will have been very long before the doubt evaporated. David Attenborough described the polar regions in his introduction as "places that feed our imaginations, places that seem to be borrowed from fairytales", and by the end it seemed like an understatement.

The landscape alone is dazzling. Last night's astonishments included the sight of a brilliant sapphire lake of meltwater, its contents overflowing along a sinuous alabaster gutter across the ice-cap until it reached a waterfall dropping a mile to the rock beneath. There was time-lapse footage of a glacier doing its unstoppable bulldozer thing with the planet and slow-motion film of icebergs calving, a titanic swash of displacement and buoyancy. Then you got animals too, sometimes just in little vignettes, such as minke whales startling an effervescence of sprats to the surface of the water, but sometimes in extended sequences as gripping as a thriller. There was a time when such dramas would have had to be collaged together from months of filming. Now you can watch from the air as a wolf pack hunts down a bison or – in the programme's most astounding sequence – get a ringside view as killer whales hunts seals.

At one moment, they bobbed up vertically from the water, eyeballing their victim from just feet away, and at the next, they swam in perfect synchronisation beneath the ice floe it was perched on, to dislodge it with an artificial wave. Even the music (all too often a blight in natural history programmes) was beautifully judged here, a low throb of tension as the victim's options steadily diminished. At the beginning, Attenborough suggested that we were going to see the frozen planet's wonders "perhaps for the last time" , an acknowledgement of the vulnerability of these ecosystems. If that's true, we'll have a beautiful record of what we've lost.

In Paul Merton's Adventures – a travelogue with Whickerish tendencies – the comedian went off to Ibiza to explore hedonism central, or "hell" as it's known to the more conservative holidaymakers among us. He did therapeutic roaring with an ex-nightclub owner, banged a bongo with the island's hippies and laid down a dance track with a local DJ. What he didn't do was take off his clothes and go skinny-dipping, despite numerous hints that he might nerve himself up for that triumph of disinhibition. Instead, he dragged up for a night on the town. That's strapping it in, Paul, not letting it all hang out.