The female great horned owl has feathers that are a mottled brown, gray, and white color. This provides camouflage as they roost in trees during the day. The exact shades can vary from owl to owl, with some females being darker or lighter in coloration. The undersides of the wings and body are paler, while the back and head are darker and barred. The throat is white.
Great horned owls are large, powerful owls native to the Americas. They are adept hunters with a diverse diet and can take prey as large as skunks, geese, and young coyotes. Great horned owls exhibit reverse sexual dimorphism, meaning that the female owls are larger than the males. They have prominent ear tufts, reddish-brown faces, and yellow eyes.
The female great horned owl’s plumage provides excellent camouflage while roosting in trees during daylight hours. Her feathers are mottled shades of brown, gray, and white. This variegated pattern blends in well against the bark and mottled sunlight of the tree canopy. The female’s underside is a lighter buff color with dark barring. The back and crown are darker shades of brown and gray with streaks of white and rufous. The throat is white.
The female owl’s camouflage makes her difficult to spot while she rests in a tree. The coloring and patterns of the plumage break up her outline and allow her to blend into her surroundings. This helps conceal the female great horned owl from potential predators and prey during the day when she is most vulnerable.
Shades and Markings
The exact colors and patterns of a female great horned owl’s plumage can vary from individual to individual. However, some general characteristics are typical of most females of the species:
- Crown and upper back: Dark brown to charcoal gray with white streaking
- Nape and sides of neck: Gray-brown barred with white
- Shoulders and wing coverts: Brown, gray, or rufous with white mottling
- Flight feathers: Gray-brown with bars of pale buff and brown
- Tail: Gray-brown with dark brown bars
- Facial disc: Tawny to reddish-brown with concentric gray circles around the eyes
- Chin and throat: White
- Chest and belly: Pale buff streaked with brown
- Leg feathers: Pale buff with brown barring
The female owl’s plumage is soft and downy which, along with its mottled coloration, allows silent flight while hunting at night. The facial disc, while appearing flattened, is composed of small, stiff feathers that help direct sound to the owl’s ears to aid in locating prey. The plumage provides excellent camouflage but also serves a functional purpose related to the great horned owl’s predatory lifestyle.
Changes Over Time
The female great horned owl’s plumage remains relatively consistent over time but can become bleached or stained from the environment:
- Juveniles start out darker and then lighten over the first year.
- Feather tips can become bleached and worn from sun exposure.
- Barred patterns on feathers become less distinct.
- Plumage can become stained from mud or dust.
- Older owls may show more white spotting overall.
Though the female owl’s camouflage may degrade, the plumage continues to serve its purpose. Great horned owls also go through an annual molt, replacing their feathers over several months. The new plumage will return the owl’s colors to their original pattern and brightness.
Below is a table comparing juvenile and adult female great horned owl plumage:
Region | Juvenile | Adult |
---|---|---|
Crown | Dark gray-brown | Dark charcoal gray with white streaks |
Facial disc | Gray-brown | Tawny with gray concentric circles around eyes |
Chest | Pale buff with little barring | Pale buff heavily streaked with brown |
Regional Variation
There are 19 recognized subspecies of the great horned owl across North, Central, and South America. Plumage can vary among these subspecies based on their geographic range:
- The palest owls are found in desert regions like Bubo virginianus pallescens of southwest U.S. and Mexico.
- The darkest owls occur in Pacific Northwest forests like B. v. saturatus and B. v. pacificus.
- B. v. wapacuthu breeds in tundra and has heavily barred underparts.
- In Central and northern South America, owls average a ruddier tone overall.
These regional color variations help the female owl blend into her surrounding habitat, providing more effective camouflage. For example, the pale desert owls match the lighter tree bark while the darker forest-dwelling owls resemble darker, moss-covered trees. Despite these subtle differences, the female great horned owl’s mottled plumage always serves the purpose of concealment.
Diet Influences Color
The great horned owl’s diet can also influence the color of her plumage. Owls that consume carotenoid-rich prey like crustaceans and fish can develop a reddish coloration:
- Crustaceans contain astaxanthin which produces reddish skin and feathers.
- Fish contain astaxanthin and other carotenoids that lead to orange-yellow hues.
- An owl with a diet rich in these food sources may become ruddier-toned.
- The carotenoids are directly deposited into growing feathers.
- This color change is most notable during molt when new feathers grow in.
Therefore, a female great horned owl living near waterways and feeding on carotenoid-rich prey will generally be more reddish-brown than one living in a drier upland habitat. Yet no matter the specific shades, the mottled pattern always provides effective camouflage.
Mirroring the Environment
The female great horned owl’s camouflage results from evolution selecting for plumage that mirrors the owl’s common daytime environments. Tree bark, lichen, leaf litter, granite rock faces, and other surfaces commonly used for roosting all share similar colors and mottled patterns with the owl’s feathers. By blending with these backgrounds, the female owl remains hidden from potential dangers during daylight hours when she is sleeping and vulnerable.
Some key examples of how the owl’s plumage matches her environments:
- Mottled gray, brown, black, and white resembles tree bark and lichen.
- Streaking and barring break up the owl’s outline against branches.
- Pale underside matches faded leaves and granite colors.
- Dark crown resembles cavities and shadowed branches.
This camouflage helps the great horned owl survive and thrive in a variety of habitats across its expansive range. The plumage pattern is so effective it has scarcely changed over the eons this species has existed because it provides such an advantage for roosting and avoiding detection.
Serving Multiple Functions
Beyond camouflage, the female great horned owl’s plumage serves other important functions related to its roosting, hunting, and breeding behaviors:
- Dense downy layer insulates the owl from wind, rain, and temperature extremes.
- Soft edges muffle sound while in flight to aid stealthy hunting.
- Dark colors absorb heat from sunlight and facilitate thermoregulation.
- Pale throat distinguishes females from males during courtship.
- Color pattern communicates species identity to other great horned owls.
The color and structure of the feathers work together to allow the great horned owl to thrive. Whether through concealing roosts, silencing flight, transmitting species signals, or regulating temperature, the female owl’s plumage enables her to survive and reproduce.
Conclusion
The female great horned owl has evolved remarkably effective camouflage plumage to help her thrive across diverse North and South American habitats. While individual birds show some variation, females typically display complex mottled patterns in shades of brown, gray, white, and rufous. This provides concealment while roosting in trees and blends with lichen-covered bark and dappled sunlight. The plumage also serves functions like weather protection, silent flight, and communication. The camouflage pattern has changed little over time because it provides such an advantage to the female great horned owl during her daily routines. So whether spotted fleeing the sun’s rise or departing in moonlight to hunt, the great horned owl’s artful plumage suits her well.