This is a pleasant enough story, with apparently intelligent writing about birds and about life as teenagers. Alex Wolff is the standout actor here, if you don't count Sir Ben Kingsley. More about him later. But Timmy is a great character. And Katie Chang makes quite a contribution also. Ellen has a nice personality and is smart, but she has had trouble making friends because she moves a lot.
Kodi Smit-McPhee does a good job of being an ordinary kid, and is most effective when David has to show grief.
Ben Kingsley makes the most of what turns out to be a small role, but his first scene is not the only one. He really shows his ability later. This isn't the type of movie you would expect him to be in, but his presence adds to the movie.
The scenery is great too when the actual bird watching takes place.
Is this is good clean family film? Not quite. There is some sex talk and some words make it to broadcast TV that younger kids shouldn't hear, though others have multiple meanings and must therefore be all right. When I saw this, fairly often, the sound went out and a character's mouth was blurred. One word in particular was actually used twice (though I heard a P once before the rest of the word was bleeped), once in subtitles when the guys were speaking Latin, and not to refer to a cat. But I don't think the revelation that Donald Trump used the word in a more vulgar way had any influence on the censors. I think they did their job long before the news about the Donald.
I didn't care for most of the music (but of course this a film for teens), but the guys do like classical music, and several scenes involving the grownups, including the wedding, had jazz that would have fit perfectly in the great Woody Allen movie set in 1940 that I saw the same weekend I saw this.
It's a worthy effort.