Feathers and Plumages
If clothes make the man then feathers make the bird. Feathers come in an amazing array of colors, including just about every hue imaginable. All of a bird's feathers are referred to as its plumage.
Photos ©Pete Hosner: Lef to right--Oriental Dwarf Kingfisher from Sabah, Bornean Malaysia; Green Broadbill from Sabah, Bornean Malaysia; Pale-Mandibled Aracari from Esmereldas, Ecuador
A bird's plumage can change over time for several reasons, including:
- passing through one or more molts until adult plumage is reached
- molting into and out of breeding plumage
- wear and tear
- bleaching by the sun
- staining by food sources and the environment
Feathers play a wide variety of roles in the lives of birds, and are critical to their specific life styles.
In some species the colors and markings of the male can have a direct impact on how attractive he is to a female, and his mating success. In a few isolated cases the roles may reverse, with the male duck looking for clues to a female's value as a mate by evaluting the coloration of her feathers.
Male ducks may look for clues to a female’s health in the white of her wings
Fickle Female Barn Swallows Prefer Strong Colors
Male Barn Swallows have a wash of reddish-chestnut color from their throats to their bellies. This color varies among birds from very pale red-brown to a dark rusty-red.
Female Barn Swallows pay special attention to the shade of red on the males. Even after they have paired with a male they will still comparison-shop for sexual partners. If her mate's red breast is not as dark as that of other males in the population, the female is likely to sneak out for a secret rendezvous with another male that has darker feathers.
Some research indicates that birds in good health are able to produce feathers with brighter colors. In establishing a nesting territory, male birds which are strongly colored may be sending a signal that they are especially fit.
The black bib on male House Sparrows seems to indicate the relative health and strength of the bird to others of its species. Studies have shown males with larger bibs are more dominate, hold better nesting territories and mate with more females.
Regulation of body temperature
Feathers serve to keep birds warm and dry. Penguin feathers are especially well adapted for this purpose. The feathers are small and densely packed. The downy base of each feather traps an insulating layer of air against the penguin's skin. The feather tips overlap each other to form a waterproof outer shield.
As with many other species, penguins preen to keep their feathers clean and waterproof. Oil from a gland at the base of the tail helps waterproof the feathers. As a penguin preens, it spreads the oil throughout its feathers, and in the process cleans and smoothes them.
The feathers of these Chinstrap Penguins keep the birds warm and dry in the frigid waters surrounding Antarctica.
Several feather types, including natal down, also serve to help birds remain warm in even the coldest weather.
The colors of a bird's feathers are often used to provide camouflage from potential predators.
The winter plumage of the Willow Ptarmigan is pure white to match the snow-covered grounds of its winter home. The spring molt produces mottled brown feathers, making the female almost invisible as she sits on her nest.
Feathers, of course, play a crucial role in flight. Feathers help create the airfoil shape to the wing that provides lift. They also support the overall shape of the wing and its flight characteristics.
Hummingbirds are especially adept at controlling their feathers, and thus the shape of the wing, as they hover while feeding.
The sharply pointed wings of the Peregrine Falcon (left) are made for speed and maneuverability; much needed traits as it hunts on the wing. The Turkey Vulture has broad, rectangular wings ideally suited for slow, soaring flight as it searchers for carrion.