This past Saturday after my encounter with a cinnamon-colored squirrel (a variant of the Common Gray variety) in Central Park, I came upon a Mallard duck preening and he can be seen in the first image atop this entry.
I am fascinating with the preening process, which I've witnessed many birds doing, including a mourning dove when he/she alighted upon the branches of an Ailanthus tree in my courtyard (as evidenced in the second photo above). Details re mourning doves and their preening process are included in volume one of my book series, Words In Our Beak. And information about Ailanthus trees is included in volume three.
Please click here to go to my blog post that provides details as to where you can get these books.