The red-breasted merganser is a medium-sized “saw-bill” sea duck. An adult weighs 800–1,350 grams (1.7–3.0 lbs) and is 51–64 cm (20.0–25.1 in.) long. Males are larger than females. Both sexes have a long narrow red bill with a black tip, red-orange feet, and black wings with white patches across the inner wing. Their serrated bill is highly specialized for grasping small fish securely.
Sea Duck Information Series fact sheet
Red-breasted Merganser Species Knowledge Summary and Information Needs [PDF]