The best estimate I can give you is "not many" but it hasn't been exhaustively studied, especially with tens of thousands of tree species. I would like to point

The best estimate I can give you is "not many" but it hasn't been exhaustively studied, especially with tens of thousands of tree species. I would like to point out though that crown shyness is a lot easier to observe in monoculture forests that were replanted after logging. A diverse forest with lots of trees is really hard to observe tree shyness in because it's a specific adaptation between members of one or a few species. If they're standing next to another species that doesn't cooperate, the shyness might not be readily visible. It's also not universal, which is why it's increasingly believed to be some sort of stress response. One patch of trees in a forest may exhibit it while another patch of the exact same species a few hundred feet away might not. It might even be the case that this is an old adaptation that most trees are capable of but no longer need.