The female scarlet tanager has a strikingly different coloration from the male. While the male is known for its brilliant red plumage, the female is a dull olive-yellow color. This distinct sexual dimorphism sets the scarlet tanager apart from many other songbird species where males and females have similar plumage. In this article, we will explore the specific colors of the female scarlet tanager, how her plumage differs from the male’s, the purpose behind this dichromatism, and how to identify a female scarlet tanager based on color.
The Olive-Green and Yellow Plumage of the Female
The plumage of the female scarlet tanager consists of olive-green and yellow colors. The upperparts, including the back, wings, and tail, are an olive-green hue. This verdant color provides camouflage when the bird is up in the treetops. The underparts are a dull yellow, lighter in color than the upperparts. The yellowish wash extends from the throat down to the undertail coverts. The wings and tail have an olive-yellow tinge. A faint olive-colored eyeline contrasts with the pale yellow lores. The bill is a dark grayish color with a paler base. The legs are bluish-gray. In flight, the female’s wings show pale yellowish panels or bars.
In comparison, the male scarlet tanager is nearly entirely crimson red. Only the wings and tail are black. The male’s bright red plumage stands out vividly against the green foliage, while the female’s subdued colors allow her to blend in.
Variation in Plumage and Molting
The plumage coloration of female scarlet tanagers can vary somewhat geographically and between individual birds. Western populations tend to be more yellow, while eastern birds are greener. Some females may have orange-tinted underparts or olive coloring bleeding into the yellow breast and belly. The shades can range from a lemon yellow to a mustard yellow. Rare variant females may have small patches or speckles of red scattered in the plumage.
Female tanagers molt into their distinct plumage starting around 90 days after hatching. Juvenile females resemble adult females but with some streaking on the underparts. With successive molts, the plumage takes on the definitive olive-green and yellow hues.
Purpose of Sexually Dimorphic Coloration
The disparity between the male’s vivid red plumage and the female’s cryptic colors serves an important evolutionary purpose. The concept is called sexual dichromatism, where males and females of the same species display substantial differences in coloration. There are two main advantages to the scarlet tanager’s pronounced sexual dimorphism.
Camouflage for the Nesting Female
The first purpose is camouflage. As the reproductive duties fall mainly on the female, she incubates the eggs and broods the altricial young. The olive and yellow plumage allows the female to blend into the nesting area, concealing herself and the nest from potential predators. The more conspicuous red male is not saddled with these incubating and brooding responsibilities, so his showy plumage does not make himvulnerable.
Studies have shown predation rates are lower for females and nests of dichromatic species compared to those where males and females have similar coloration. Cryptic female plumage provides an adaptive advantage in avoiding detection.
Signaling Fitness in Males
Secondly, the vibrant red plumage signals health and fitness to potential mates in male scarlet tanagers. Producing colorful carotenoid pigments requires the male to be an excellent forager. His ability to find scarce food resources demonstrates his genetic fitness. Females preferentially choose the brightest red males to sire their young. Brighter males also tend to have greater reproductive success. The male’s red coloration is therefore an honest indicator of quality.
Identifying Female Scarlet Tanagers
When trying to identify a female scarlet tanager in the field, the first step is to note the species’ geographic range and preferred habitat. Scarlet tanagers breed in deciduous and mixed forests across eastern North America. They winter in South America. These songbirds favor mature, open-canopied woods with some understory vegetation.
Next, look for a medium-sized songbird with a stout, finch-like bill. Shape and proportions are similar to an American robin. Focus on the plumage colors – olive-green above, yellow below, with yellowish wings and tail. The face has a pale yellow wash contrasting with an olive eyeline.
behaviors can aid identification. Female scarlet tanagers methodically move through the upper and mid-levels of the canopy searching for insects. If the bird flies, note the pale yellow wing bars. The flight style is often described as undulating. Females give a hoarse, chipping call very different from the male’s song.
In the same habitat, female scarlet tanagers could potentially be confused with several species. These include female summer tanagers, female western tanagers, some warblers, and female rose-breasted grosbeaks. Paying close attention to plumage colors, patterns, sizes, and proportions will help rule out those other species.
Key Identification Points
- Olive-green upperparts
- Yellow underparts
- Stout finch-like bill
- Plain face with pale lores
- Yellowish wings and tail
- White wing bars in flight
- Foraging maneuvers through canopy
- Harsh chipping calls
Conclusion
While not as brilliantly colored as the male, the olive-green and yellow plumage of the female scarlet tanager is beautifully adapted for her nesting duties. The sexual dichromatism provides the female with camouflage and the male with a way to signal his fitness. Careful attention to size, shape, colors, patterns, sounds, and behaviors allows observant birders to identify female scarlet tanagers.
Plumage Area | Color in Female Scarlet Tanager |
---|---|
Back | Olive-green |
Wings | Olive-yellow |
Tail | Olive-yellow |
Throat | Pale yellow |
Breast | Yellow |
Belly | Yellow |
Undertail Coverts | Yellow |
Bill | Dark gray with pale base |
Legs | Bluish-gray |