The extraordinary mating rituals of the emperor penguins are documented in this fascinating, lovingly made film by Luc Jacquet, who, along with his dedicated crew, spent more than a year in Antarctica filming the flightless birds as they leave their sea home and trek over miles of ice-covered terrain to their breeding grounds, where they form couples to produce the eggs from which the next generation will hatch. But that’s just the beginning. After laying the eggs, the females turn them gingerly over to their male partners, who shelter them beneath their bodies in the frigid environment while the females waddle back to the sea to feed and secure nourishment for the fledglings that will have hatched by the time they return after another long trek. The newly formed families that have survived the entire ordeal then make the journey back to the sea together, where they’ll reside until the following year.

“March of the Penguins” has one fundamental problem that’s endemic to nature documentaries such as this–a tendency to anthropomorphize what’s actually a natural (if incredible) phenomenon of the animal world by bandying about words like “concern” and “love” to refer to the birds’ conduct. At that, however, the Americanized version being distributed in this country represents an improvement over the French original, which was not only longer but concentrated on a single penguin couple, presenting them in nearly human terms (and even having actors provide “voices” for them as they mate). That misguided idea has happily been jettisoned in favor of a more reserved narration, penned by Jordan Roberts and voiced by Morgan Freeman in tones that capture a proper mixture of astonishment and scientific observation, but do so gently enough not to become grating. And the images captured by Jacquet and his team are often extraordinarily beautiful, and occasionally haunting. The sequences of the penguins waddling toward the mating grounds, which they apparently recall through the agency of some evolutionary inner compass, are breathtaking (and sometimes laugh-out-loud funny when one of the birds slips and falls onto its back); but they’re surpassed by the sight of the massed males huddling together in the sub-zero temperatures to protect the eggs while awaiting the females’ return. (It’s at such moments that one’s amazed by what the filmmakers endured to capture the footage–we get some glimpses of them at work in the snippets that accompany the final crawls.)

There are a few scenes in “March of the Penguins” that will be a bit strong, especially for younger viewers–as when older penguins expire during their long journey, or eggs are broken before hatching, or (especially) females fail to return from their search for nourishment. Though the narration soothingly refers to the fate of victims with a euphemism, saying that all traces of them simply “disappear” in the snow, the harsh reality can’t be so easily erased. That’s why the film really works better as a depiction of the wondrous but also savage character of the natural world rather than the sort of anthropomorphic love-fest the makers (especially in the French version) sought to make it. On that basis, though, it’s a visually overwhelming portrait of a little-known phenomenon, and most viewers will find it enthralling.

And one thing’s certain: with this picture and “Madagascar,” the penguins are enjoying a banner cinematic summer.