On the ground, condors seem spectacularly ugly things, writes Sian Brewis. Scabby pinky purple heads, bright laser-like red eyes, an ungainly gait and, most disturbingly, yellow tongues.

But in flight it's another story. Their wings buffeted on thermals above Patagonia, they soar and swirl around majestically, eyes peeled for bits of old carcass lying about.

In Earthflight (BBC1, 8pm) we have been along for the ride, seemingly alongside the birds as they fly and scan the horizon for tea.

It has been jaw-dropping television, reminding us yet again just how fabulous nature is, though goodness knows how it is filmed – tiny cameras on the back of the birds?

Unlikely. Microlight cameras? All will be revealed, apparently, in the last episode.

However it's done, it's amazing. Last night, we were in the Amazonian rainforest, flying alongside scarlet macaws in search of the ultimate antacid – a miracle clay that sorts you out if you've eaten something dodgy.

Every creature in the forest seemed to be eating it, too. It was being wolfed down faster than aspirin after the Christmas party.

I would not be surprised if after this, someone from a pharmaceutical company starts digging up mounds of the medicinal mud for tests.

Watching the macaws feeding was a creature which looked like a Disney character of pure evil – a harpy eagle.

The feathers around its head acted like the witch's cloak in Snow White.

Elsewhere, a hummingbird in glorious Technicolor was feeding on nectar, its feathers glowing with an iridescent sheen.

But the cute award goes to the dusky swifts which live around a giant waterfall.

They huddle up together, stretching out their feathers to form a protective quilt, and sleep in the rock crevices as the waterfall rages past.

"To them, it's like lullaby, soothing them to sleep," As if on cue, a little bird yawned.

The power to read minds, being able to be invisible, flying – all credible super powers. But having an amazing memory?

Not sure how that would pan out. It would be annoying for a start. Imagine never being able to gently forget the time you got really drunk and... Ah well.

New cop series Unforgettable (Sky Living, 9pm) stars flame-haired Poppy Montgomery (Without a Trace) as a cop who cannot forget anything. (Except, seemingly, to get dressed properly at crime scenes, unless vest tops have become regulation.)

When colleagues flounder, she is able to delve into her memory and "see" the moment when she saw the vital clue.

Likeable enough, but it seems too obsessed with the gimmick to allow characters or plot to develop.