Peagawk can stuck with a corner

That's not a bug, same thing you could do with gobbler in the basic DS (cornering, not plucking feathers part)

Edited November 10, 2018 by krolowanocy

Before the open beta, you could use a fruit to lure a peagawk into a pen, and it would be too distracted to notice you plucking its feathers and keeping it in a cage for later. Now, peagawks will run away even  while going after a fruit.

 

If they prevented you from easily caging it AND from them getting stuck on terrain, you would have to wait for them to fall asleep, get one feather, and rinse and repeat until either you have enough feathers or it becomes day time. It'd be possible, but extremely tedious.