Except for a very small percentage of shotguns that are used for longer range slug shooting, I can't think of a real practical application for a bipod.

For carrying in the field hunting birds, rabbits or even squirrels there's no use for one. For wing shooting there's no use for one. For Turkey hunting there's no way to know how a bird will approach. You really need to be able to move and adjust quickly. Except maybe for very limited applications in a blind or with a young hunter that can't hold up the gun very long, a bipod would only get in the way.

Also, many of the bipods you see on rifles lately aren't there because they are needed, but for looks.