The short answer
Some birds can change colors, while others cannot. Birds that can change color do so through feather pigmentation, anatomical changes, or light refraction. Species like parrots and cockatoos have special cells that allow them to change the pigment in their feathers. Other birds, like the willow ptarmigan, change colors seasonally as their plumage molts. Still others, like hummingbirds, can alter their apparent color through iridescent feather structures that refract light differently at different angles. So in short, while most birds maintain the same plumage coloration year-round, some exceptional species have evolved unique mechanisms to enable color changes.
How bird colors are produced
Birds derive their feather colors from two main sources: pigments and structural colors. Pigments are chemical compounds in feathers that selectively absorb and reflect specific wavelengths of light. The most common feather pigments are melanins (producing blacks, grays, browns) and carotenoids (producing reds, yellows, oranges). Genetic factors determine the types and amounts of melanins and carotenoids birds can synthesize. Structural colors result from microscopic feather structures that interfere with light waves to produce colors through refraction, diffraction, or scattering. Examples include the iridescent blues, greens, and purples sometimes seen on feathers. Unlike pigments, birds can actively control and change structural colors using mechanisms like microscopic muscle contractions around the feather cells.
Birds that can change color
Parrots
Many parrot species, including cockatoos, conures, and macaws, can voluntarily change the color of their plumage. These birds have a class of specialized cells called melanophores that contain granules of the pigment melanin. By dispersing or aggregating the melanin granules within the cell, parrots can alter their apparent color. For example, the melanophores may concentrate melanin to make the feathers appear very dark, or they may spread it out to make the feathers appear light or multi-hued. This allows parrots to create temporary patches of color on parts of their plumage.
Phasianids
Birds like ptarmigans and grouse have plumage that changes from brown to white as winter approaches. This seasonal color change helps camouflage the birds against snowy backgrounds. The mechanism involves the gradual molting and replacement of feathers as daylight hours decrease. In addition to melanin pigments, some of the new white feathers may also lack carotenoid pigments, enhancing the color change. Males and females may go through the color change at different rates, with females often changing earlier.
Hummingbirds
While hummingbird colors are primarily produced by pigments, some species also have modified feather structures that create iridescent and changeable colors. As the bird moves, the refracted light shifts, causing certain feathers to seemingly change from red to orange, yellow, green, blue and/or purple. Male hummingbirds will display these iridescent feathers during courtship. The feathers are constructed so that air bubbles trapped inside cause interference patterns with light waves. By controlling feathers around these specialized structures, hummingbirds can actively control their iridescence.
Birds that do not change color
The vast majority of birds have static plumage colors that do not change. There are several reasons most birds lack mutable coloration:
- Their feathers only use melanin pigments, which produce limited color ranges.
- They cannot synthesize special pigments like carotenoids.
- Their feathers lack structural modifications for iridescence.
- They genetically cannot generate new feather types after molting.
- They lack anatomical structures like melanophores that allow color changes.
Here are some examples of birds with static, unchanging colors:
Penguins
Penguins have a white belly and black back, wings, and head. Their plumage comprises only melanin pigments and lacks structures to create iridescence. Penguin species and populations have distinctive melanin patterns adapted to their environments, but individuals cannot alter their colors.
Owls
Most owls display cryptic brown, tan, black, white, and grey plumage. These muted colors help owls camouflage against tree bark and blend into shadowy habitats. Their feathers utilize various melanin pigments but generally lack carotenoids and iridescent structures. This means owls cannot actively change their colors, although some species will look nearly white after bleaching in the sun.
Gulls
Gulls have white plumage with gray or black accents on the wings. Their white color comes from a lack of melanin in those feathers, while the darker markings come from melanin pigmentation. Gulls of the same species and gender maintain these patterns year-round. Without specialized melanophores or iridescent structures, individual gulls cannot alter their plumage.
Why some birds evolved color changing abilities
- Camouflage – Seasonal changes between brown and white help birds like ptarmigans blend into the environment as snow cover changes.
- Mating displays – Male birds use bright and iridescent colors to attract females.
- Communication – Parrots change colors to communicate mood, health, and dominance.
- Thermoregulation – By exposing more dark or light feathers, birds can better regulate body heat.
- Identification – Subtle changes help birds recognize and identify members of their own species.
The ability to change colors provides birds with advantages in survival, reproduction, and social interaction. For most species, however, static plumage coloration is sufficient, as it has evolved to suit their lifestyles and habitats. But for some specialized birds, mutable coloration provides a competitive edge.
Methods birds use to change colors
Birds that can alter their plumage color use one or more of the following methods:
Melanin granule dispersal
Specialized cells called melanophores allow birds like parrots to change color by distributing or concentrating melanin granules. Dispersion exposes more melanin to create darker colors. Concentration aggregates the pigment, making feathers appear lighter or less saturated.
Carotenoid availability
Some birds can control the types and amounts of carotenoid pigments in their feathers. Adding certain carotenoids creates richer yellows, oranges, and reds. Withholding or removing them results in muted white and brown plumage. Birds access carotenoids through their diets.
Feather replacement
Molting and growing new feathers allows seasonal color changers like ptarmigans to transition between brown and white plumage. Photoperiod and hormones initiate the molt as winter approaches.
Structural iridescence
Some birds have feathers with specialized structures that use light refraction, diffraction, and scattering to produce iridescent, changeable colors. By controlling feathers around these structures, birds can alter the colors displayed.
Feather fluffing
Raising or compressing plumage feathers changes their light exposure and appearance. Some birds will fluff feathers to display more white, or compress them to show more dark pigmentation.
Limitations and challenges of changing colors
While some birds can actively change their colors, this ability also comes with some limitations and costs:
- Energy expenditure – Alterning melanin granules requires energy expenditure.
- Slow speed – Color changes via molting happen gradually, not instantly.
- Diet dependence – Carotenoid-derived color changes rely on specific dietary sources.
- Layering issues – Structural iridescence may get blocked by overlying feathers.
- Complex genetics – Color-changing abilities require specialized genetics and physiology.
- Signaling costs – Conspicuous mating displays increase predation risks.
These limitations help explain why color-changing abilities are relatively uncommon among birds, occurring only in certain specialized species and contexts. The costs and constraints outweigh the benefits for most birds.
Examples of color-changing birds
Here are some specific birds that can change their colors along with details on how they accomplish this:
Indian Ringneck Parakeet
This popular parrot species can alter its green plumage patches to appear more blue, yellow, or orange. It does so by using melanophores to disperse and aggregate melanin granules in its feathers.
Willow Ptarmigan
These grouse birds molt from summer brown plumage to winter white plumage. The change helps camouflage them against snow.
Northern Flicker
A North American woodpecker, this bird grows bright yellow feathers on its wings and tail during mating season. It gains the yellow color from added carotenoid pigments obtained through its diet.
Anna’s Hummingbird
The male has iridescent rose-red throat feathers. By controlling surrounding feathers, it can alter the throat patch to flash different hues ranging from red to green to yellow.
Gouldian Finch
This finch has a red, black, or orange head. Its color depends on which carotenoid pigments it ingests through its diet. Supplements can be used to intentionally change its colors.
The unique nature of birds that change color
While most birds have static coloration, the ones that can alter their plumage colors represent a rare and unique phenomenon in the avian world. Some unusual traits of these color-changing birds include:
- Specialized feather cells – Contain organelles like melanophores for color shifts.
- Unique molt patterns – Allow seasonal color transitions.
- Modified feather structures – Enable iridescent color through optics.
- Flexible diets – Allow ingestion of carotenoids for color variation.
- Rapid signaling – Color shifts can occur instantly for communication.
- Extra energy costs – Require additional energy expenditure for color modulation.
- Distinct genetics – Posses rare genes coding for color change.
The mechanisms behind color changing have evolved through natural selection favoring birds with adaptive, dynamic coloration. While relatively rare across all bird species, the phenomenon illustrates the innovative solutions and specializations that can arise through evolution. Scientists continue studying these unique birds to better understand the genetic, physiological, and evolutionary basis of their distinctive color changing abilities.
Conclusion
While most birds have fixed plumage colors, some species can dynamically change their feather coloration. Through processes in specialized cells and feather structures, birds like parrots, grouse, and hummingbirds can shift between color states or create illusory iridescent hues. This ability provides advantages for camouflage, mating, thermoregulation, and social signaling. However, mutable colors also come with costs and limitations that make the trait rare overall among birds. The few species with mutable colors remind us of nature’s incredible capacity for innovations that expand avian visual signaling capabilities beyond static reliance on melans and carotenoids. From drab to dazzling, the mechanisms behind birds’ changeable colors illustrate the ingenuity inherent in evolution’s problem-solving process.
