Bird-watching seems about as cinematic a subject as fly-fishing, but the latter did spawn “A River Runs Through It,” so “The Big Year,” inspired by Bob Obmascik’s non-fiction book about three birders attempting to spy the largest number of species in a calendar year (a competition known in the trade as “doing a Big Year”), shouldn’t be summarily written off. It boasts a starry cast, with Steve Martin, Jack Black and Owen Wilson representing very different comic styles as the trio of rivals, as well as a director—David Frankel—who proved his aptitude with “The Devil Wears Prada” and (some would say) “Marley & Me.” And yet while likable enough, the movie proves a curiously pallid, choppy mixture of farce and sentiment that doesn’t take full advantage of what the stars have to offer.

The “pallid” description especially applies to the usually rambunctious Black, who despite a few pratfalls and one crazy dance goes mostly for Buster Keaton-style restraint as Brad Harris, the regular-guy member of the trio, who also narrates. Harris is a staffer at some sort of energy firm who fulfills a lifelong dream to join the “Big Year” competition while holding down his regular job. He also has to deal with the exasperated incomprehension of his practically minded, no-nonsense father (Brian Dennehy), though his mother (Dianne Wiest) is enthusiastically supportive

Meanwhile Stu Preissler (Martin), the wildly successful founder of a big corporation, is determined to retire and do what he’s always wanted—a Big Year. He’s got the support of his lovely wife Edith (JoBeth Williams), but the guys to whom he’s turned over the business (Kevin Pollack and Joel McHale) keep trying to pull him back into the negotiations they’re involved in, and his son’s wife is about to give birth to his first grandson.

Then there’s Kenny Bostick (Wilson), the current world’s record holder at 732 sightings, who joins the competition for fear that somebody will best his total. He’s seen as arrogant, manipulative and underhanded, and his obsession threatens his marriage to lovely Jessica (Rosamund Pike). But he proves a formidable competitor, and in the end he shows that despite his failings, he’s honest about following the rules.

The movie’s arc is all too familiar. Hank and Stu become friends—despite one episode that threatens to derail their camaraderie—and urge one another on. Hank continues through the year despite financial obstacles, and bonds with his dad after the old man suffers a heart attack and comes to understand his son’s dream. And Stu finishes the competition as well, overcoming the tug of his old company while taking time off to visit with his son’s baby. Kenny, on the other hand, shows greater single-mindedness.

The final message of the picture is familiar, too. Following your dream is a good thing, but winning is less important than love and family. So Hank winds up with a renewed relationship with his parents, while Stu returns to the bosom of his enlarged brood, even rejecting an offer to head a much larger conglomerate that’s buying his old company. And Hank gets a girlfriend, too—Ellie (Rashida Jones), a birder he’s long been gaga over but too shy to approach until he got encouragement from Stu.

That’s all well and good, but it doesn’t make up for the episodic quality of the picture, or for the fact that the episodes are flaccidly executed. The locations in the on-the-road segments are attractive, and nicely shot by cinematographer Lawrence Sher, but the sequences themselves have relatively few high points, and most of them are so short—consisting of folks dashing hither and yon to places where rare birds have been spotted—that they barely register (the numbers flashing by that show the three guys’ current sightings, moreover, seem to have little connection to them). The back-home interruptions don’t offer much compensation, though their sentiment quotient is substantially higher.

Among the stars, Black’s laid-back approach comes as somewhat of a relief after his frantic turns elsewhere, but he’s not naturally a sad-sack type, while Martin is mostly in his dull “Parenthood” mode. Anyone hoping that the pairing would result in the sort of chemistry that Martin enjoyed with John Candy in “Planes, Trains & Automobiles” will be gravely disappointed. Meanwhile Wilson just coasts along on a smirk and his usual slacker-dude shtick. Among the rest of the cast Dennehy does his customary gruff-but-with-a-soft-heart bit, Anjelica Huston relishes playing it broad as captain of a tourist boat, and Williams is an oasis of calm as Stu’s wife. But Wiest rather overdoes the doting mother. Tim Blake Nelson, Anthony Andrews, Steven Weber and Barry Shabaka Henley are among the other familiar faces who show up for what amount to cameos.

But with three such major comic stars sharing top billing, one might expect a lot of big laughs from “The Big Year.” But they’re as rare here as some unusual species must be in a typical day of birding. By trying too hard to be nice, the movie just ends up feeling limp.