Kodi Smit-McPhee plays David, a high school student whose father is about to remarry after the death of his mother. He's not dealing well with the loss of his mother, and has followed in her footsteps as a passionate birder. His friends at school are also birders, and on the eve of his father's wedding, he runs off in pursuit of a possibly extinct bird that he saw, accompanied by his two friends and "the new girl," and eventually joined by Lawrence Konrad (Ben Kingsley), an avid birder they all look up to.
This is an indie movie with a tiny budget, or at least if there was any budget they spent it all on Kingsley (although my suspicion is he worked for the Hollywood equivalent of peanuts because this looked like fun). But the kids do a passable job in the service of a fairly good story, life lessons are learned, etc. (it's essentially a coming-of-age story). Which makes it sound more quaint and clichéd than it is: it's ultimately quite enjoyable.