Goffin Cockatoo has what looks like a blood blister below left eye
I noticed last night that my female 15 yr old Goffin's Cockatoo has a redish-brownish area just below the bare skin area on the left eye. I used a damp cloth to see if perhaps it was blood from a broken blood feather as it has the color and appearance of old blood, but nothing came off. It doesn't seem to bother her, but I also know birds are good at hiding that sort of thing.
Other than this area, she is very healthy - eats a pelleted diet, is supplied with toys and gets at least 1-2 hours out of her large cage each day, if not more.