-save/load bird form
save current shape with a bumper+button press
return to that shape with a button press
cycle through saved shapes with bumper

This feature would allow us to save forms for particular purposes and switch to them on the fly, or swap through our presets at will

-join/form flock
a call or birdsong that summons all similar birds in the area to form into a flock that remains with the player character. Conversely, an auto-pilot function that makes your bird join an existing cluster of creatures and blend in while AI takes over your behaviors

imagine flying into a flock of ducks, then quacking at them and all flying away together in a giant V shape, trying to fly through a cave and watching them flop into the walls while only you manage to thread the needle
finding that one spot with like thirty butterflies, hitting the autopilot and fluttering in the wind together across a hilltop while you eat a sandwich and get crumbs in your keyboard. Basically an eye-candy mode

-rando-bird idea
your character changes shapes to a random hybrid every x seconds (x being some configurable variable by use of aforementioned morph buttons)
use a button press to stop/resume transforming