Theres a stationary bird in my garden?

Theres a bird in my garden which wont move for anything, it has been on the leg of a chair for 1 day and 1 night now and has accumulated a lot of poo. It was incredibly windy and it can fly and walk okay because 2 days ago it went from under the chair to ontop of the chair what can we do to get it to move or whats the protocol in this situation