The Blackpoll warbler (Setophaga striata) is a small songbird that breeds across Canada and the northern United States before migrating to the Caribbean, South America, and their off-shore islands in the fall. As with many warblers, the Blackpoll warbler has different plumages depending on the season. In the spring and summer breeding season, the Blackpoll warbler has bright breeding plumage. In the fall and winter when it migrates and overwinters, its plumage is more subdued. This helps it blend in better in its overwintering habitat.
Fall Plumage
The fall plumage of the Blackpoll warbler can be described as follows:
Overall color
The overall color of the fall Blackpoll warbler is dull olive-gray above and yellowish-white below. This provides good camouflage among the browns, yellows, and greens of its migration and overwintering habitats.
Crown
The crown of the Blackpoll warbler is a dull gray-olive color. There are no bold black crown stripes as seen in spring and summer.
Face
The face is a dull yellow-olive color, lacking the bold black cheek patches and white eyestripes of summer. There is a faint yellow tinge around the eye.
Throat
The throat is pale yellowish-white in fall, without the vivid black throat patch seen during the breeding season.
Breast
The breast is a pale yellowish-white, again lacking the bold black breast band and white underneath of summer. There are faint gray-olive streaks on the sides of the breast.
Belly
The belly is pale yellowish-white like the throat and breast.
Wings
The wings are dull gray-olive like the back and crown. The wing bars are faint white lines compared to the crisp white bars of summer.
Tail
The tail is dark gray-olive with small white spots near the tips of the outer tail feathers. The white spots are much reduced compared to the broad white patches seen in summer.
Differences from Summer Plumage
The fall plumage of the Blackpoll warbler differs from the summer breeding plumage in the following ways:
– Overall colors are duller and paler
– Crown lacks black stripes
– Face lacks black cheek patches and bold white eyestripes
– Throat lacks black throat patch
– Breast lacks black breast band and white underneath
– Wings lack bold white wing bars
– Tail lacks broad white patches
These differences make the fall Blackpoll warbler much more nondescript and camouflaged compared to its bold summer breeding colors.
Why Does Plumage Change in Fall?
There are a few reasons why the Blackpoll warbler’s plumage changes in the fall:
Camouflage
Dull fall plumage provides better camouflage and less visibility to predators during migration and in overwintering habitats.
No need to attract mates
Bright breeding plumage helps attract mates in spring and summer. Dull non-breeding plumage may save energy when not trying to attract mates in the fall and winter.
Wear and tear
Bright feathers get worn down throughout the breeding season. New dull-colored feathers molt in before fall migration.
Conclusion
The fall plumage of the Blackpoll warbler can be summarized as an overall dull gray-olive above and yellowish-white below. It lacks the bold black-and-white facial patterns, breast bands, and white patches of summer breeding plumage. These dull colors act as camouflage during migration and in overwintering areas. The seasonal change in plumage helps optimize the warbler’s appearance and energy use for breeding versus migration and winter survival.
Plumage Area | Summer Breeding Plumage | Fall Non-breeding Plumage |
---|---|---|
Overall color | Black and white stripes above, yellow below | Dull olive-gray above, yellowish-white below |
Crown | Black stripes | Dull gray-olive |
Face | Black cheek patches, bold white eyestripes | Dull yellow-olive, faint eye ring |
Throat | Black throat patch | Pale yellowish-white |
Breast | Black breast band, white underneath | Pale yellowish-white with faint streaks |
Belly | Yellow | Pale yellowish-white |
Wings | Black with bold white bars | Dull gray-olive with faint bars |
Tail | Black with broad white patches | Dark olive-gray with small white spots |
Blackpoll warblers are one of the longest-distance migrators of all warblers. They breed in Canada and the northern United States, winter in South America, and fly nonstop for up to 2,500 miles over open ocean during fall migration. Preparing for such an epic journey requires many changes, including putting on a more subdued and camouflaged plumage. The fall plumage helps the warbler safely and discreetly navigate thousands of miles until the next spring, when the breeding colors return.
The transformation between showy breeding plumage and camouflaged non-breeding plumage is not unique to the Blackpoll warbler. It is a common strategy seen in many migratory songbirds. By modifying their appearance seasonally, birds can maximize visually social displays needed for attracting mates while also optimizing cryptic coloration for long migrations and periods when standing out is detrimental. For the long-distance Blackpoll warbler, dull fall plumage is an essential part of its marathon migration and survival until the brilliant breeding colors return next spring.