Merlin (Falco columbarius)
Prospect Park, Brooklyn, NY, Winter, 2013
Feathers are paramount to a birds survival. Each one must be zipped and straightened. A bird can reach all the feathers besides what is above the neck. Birds often preen each others head feathers. Merlins are solitary birds until breeding season.
Parrots like their heads scratched and the back of their necks. Usually they don't like their wings touched or parts they can reach. I had an African Grey that would gently but firmly grasp my finger with her beak and move it to the back of her neck if I touched her wings.