Bird Illustrations

Parrot feathers do not actually have green pigment in them. It is the texture or structure of the feathers that creates the green and blue colors. (See What Gives Feathers Their Color.) Carotenoids are pigments that are influenced by diet. Psittacin and melanin are other pigments that influence bird feather coloring.

Moulting is the process of shedding old feathers (or old hair in mammals, old skin in reptiles and old exoskeleton in arthropods). Most birds moult at least once a year. The feather coloring after the moult is referred to as "basic plumage". If the bird moults again before breeding season, the feather coloring that follows is referred to as "alternate plumage". It is often more colorful than basic plumage. As the bird begins to shed old feathers (generally starting at the head and progressing to the tail), pin feathers come in, after which more feathers are shed. A pin feather is a developing feather. It looks like a short feather shaft. It has a blood supply. If damaged, the bird can bleed. As the pin feather grows, the blood supply remains only in the base of the feather shaft and the feather remains encased in the shaft. Birds preen to unfurl the feather from the shaft encasing it.