Some body parts you should know:

MANTLE: the upper back
AURICULARS: side of the head, around the ear
SCAPULARS: feathers at the base of the wing, around the shoulder
FLANKS: the side of the belly
SPECULUM: a patch of distinctly coloured secondary wing feathers
TARSUS: leg
TIBIA: thigh or upper leg
AURICULARS: cheek
UPPER MANDIBLE: upper bill
LOWER MANDIBLE: lower bill
EYE RING: a thin line of feathers that circle the eye
MEDIAN LINE: the feathers between the crown and the eye stripe
CERE: the area at the top of the beak where the nostrils are located
PATAGIUM: the leading area of the wing between the head and the wrist
NAIL (or BEAN): the small round bump on the end of a duck's bill