I had similar thoughts about the bird's fall. There is also a special case of falling, for which you will have to come up with something. This special case is a fall into the water. When you increase the realism of the bird should drown in the water. Will it fit into the peaceful atmosphere of the gameplay?
I'm not sure I understood the idea well.
When falling into the water, there is a deterioration in controllability with the corresponding animation and then the controllability is lost completely if the player does not take the right actions. The bird goes into the mode of being on the surface, from which it is possible to perform a second take-off. The same mode as on land or very close to it.
If that's your idea, I think it's pretty good on the whole.