Taking a mid-morning walk and this one was making a racket in the mangroves off the path. I think he was trying to get the seagrapes but not sure.
This is the gulf coast of Florida south of Tampa Bay.
I believe it is seagrape. (Not the same as the edible seaweed popular in Asia.)
https://gardeningsolutions.ifas.ufl.edu/plants/trees-and-shrubs/trees/seagrape/