Budgerigar in the context of "Petal color"

A biological pigment, also known simply as a pigment or biochrome, is a substance produced by living organisms that have a color resulting from selective color absorption. Biological pigments include plant pigments and flower pigments. Many biological structures, such as skin, eyes, feathers, fur and hair contain pigments such as melanin in specialized cells called chromatophores. In some species, pigments accrue over very long periods during an individual's lifespan.

Pigment color differs from structural color in that it is the same for all viewing angles, whereas structural color is the result of selective reflection or iridescence, usually because of multilayer structures. For example, butterfly wings typically contain structural color, although many butterflies have cells that contain pigment as well.

Aviculture is the practice of keeping and breeding birds, especially of wild birds in captivity in controlled conditions, normally within the confines of a cage or an aviary.

Some reasons for aviculture are: breeding birds as a hobby, a business like a zoo, or sometimes for research and conservation purposes to preserve and protect some endangered avian species that are at risk due to habitat destruction, the illegal wildlife trade, diseases, and natural disasters. Aviculture encourages conservation, provides education about avian species, provides companion birds for the public, and includes research on avian behaviour. Popular birds people like to keep and breed include budgerigars, cockatiels, finches, macaws, domestic canaries, columbidae (pigeons and doves), loriini (lories and lorikeets), cockatoos, conures, and African grey parrots.

The uropygial gland, informally known as the preen gland or the oil gland, is a bilobed sebaceous gland possessed by the majority of birds used to distribute the gland's oil through the plumage by means of preening. It is located dorsally at the base of the tail (between the fourth caudal vertebra and the pygostyle) and is greatly variable in both shape and size. In some species, the opening of the gland has a small tuft of feathers to provide a wick for the preen oil (see below). It is a holocrine gland enclosed in a connective tissue capsule made up of glandular acini that deposit their oil secretion into a common collector tube ending in a variable number of pores (openings), most typically two. Each lobe has a central cavity that collects the secretion from tubules arranged radially around the cavity. The gland secretion is conveyed to the surface via ducts that, in most species, open at the top of a papilla (nipple-like structure).

A pin feather is a developing feather on a bird. This feather can grow as a new feather during the bird's infancy, or grow to replace one from moulting.

The pin feather looks somewhat like a feather shaft. However, unlike a fully developed feather, the pin feather has a blood supply flowing through it; at this stage, it may also be called a blood feather. As such, if the pin feather is damaged, a bird can bleed heavily.