Don't call them birdwatchers. "The Big Year," directed by David Frankel, is about three birders: Stu Preissler (Steve Martin), a wealthy businessman with a well-balanced life; Kenny Bostick (Owen Wilson), whose obsession with birding threatens his marriage; and Brad Harris (Jack Black), a young man who uses birding as a substitute for what's missing elsewhere in his life. The film follows the three for a year — a "Big Year," the name for the competition in which birders vie to see who can spot the most species of birds in North America in a calendar year.

There's much to enjoy in their quest, if you enter this movie with the right expectations. I was imagining, for no particular reason, a Christopher Guest-style mockumentary (really, wouldn't this be a great world in which to set a "Best in Show" sort of movie?) — and this isn't it, at all. Those drawn in by the line "By the director of 'The Devil Wears Prada' " on the posters might be disappointed, too; there's nothing remotely like Miranda Priestly's bitchiness here.

Instead, "The Big Year" is that rarity: a genuinely sweet film, about nice people happily engaged in the pursuit of something they love. There's no violence, no sex, no bad language, no gross-out jokes — and, unlike Frankel's "Marley & Me," no cheap tears. We do see that Kenny's marriage falls victim to his obsession, but he and his wife Jessica (Rosamund Pike) seem like a mismatch anyway. There's almost an innocent quality to this film, and it sneaks up on you.

At first, "The Big Year" may feel a little slow, but as it progresses, you find yourself rooting for the guys to spot that pink-footed goose or great spotted woodpecker. You become charmed by the gradual friendship formed between Stu and Brad, and are reminded again that nobody on screen conveys joy quite like the ever-explosive Black, whose "victory dance" (he does it twice, only once for a bird) is a miniature symphony of happiness. And you learn a few things about birds, and about life. Not bad, for one little movie.

Moira Macdonald: 206-464-2725 or mmacdonald@seattletimes.com