covers the body and produces feathers and a variety of other external
structures: beak covering, wattles, comb, scales of feet and legs. The
skin is thinner than mammalsí and attaches to the skeleton in a number
of places: skull, beak, wrist, wing tips, dorsal side of the pelvis,
tarsometatarsus, and toes. The general function of the skin is protective,
the base of external features, and serves as a large sensory organ with
receptors for temperature, pressure, and vibration. One or two glands
at the base of the tail (uropygial glands) produce fatty secretions.
the one most distinguishing characteristic of birds.
See Feathers lecture
for more details.