Back to Basics – Plumage in Winter

Lately, it hasn’t always been apparent that the Chicago area is knee-deep in winter – for one thing, there’s been very little snow to be knee-deep in! However, many birds in our area provide a clue to the current astronomical season: their winter plumage.

There are several factors that cause the change in plumage of adult birds that we may witness during winter. The primary ones are molting and wear, or abrading. What we see in winter is non-breeding or basic plumage. The bright plumage (particularly of the males) that we see for only a few months of the year is the breeding or alternate plumage. All birds have basic plumage–some birds all the time–and many birds have alternate plumage. It’s by the process of molting that all birds replace old, worn feathers, and at that time many birds change their look from basic to alternate plumage. In addition, some birds experience a complete molt with every feather replaced, while others do a partial molt where, for example, only flight feathers are replaced. Abrading causes color change in the tips of feathers by simple wear and tear: flapping and environmental elements result in fraying of feather tips.

Two prime local examples of changes in plumage resulting from abrasion are European Starlings and Northern Cardinals. The breeding plumage of starlings is black with iridescent purple and green. But after molting, we see the basic plumage, which is white-speckled. The white speckles are the white tips of the basic plumage's black feathers. The white tips wear off by abrasion, and by breeding season, what’s left are all black feathers. The black feather tips are less resistant to abrasion, as the black feathers have more melanin,a pigment that strengthens cells and protects them from damage.

European Starling, alternate plumage    Cole Parks/Audubon Photography Awards

European Starling, basic plumage    Mark Washburn/Audubon Photography Awards

The male cardinal, a favorite photography subject in winter, has a gray or olive-gray tinge to the back and neck feathers post-molt. But by late winter/early spring, those grayish tips have worn off, and our most colorful bird in winter is even brighter.

Northern Cardinal, alternate plumage   Nancy Erickson/Audubon Photography Awards

Northern Cardinal, basic plumage  Russell Torres/Audubon Photography Awards

A dramatic example of the effects of molting on another year-round resident is the American Goldfinch. At the end of summer, goldfinches molt all their feathers and acquire drab, olive-green feathers with bright buffy or white wing bars; our goldfinch is no longer conspicuous among our other common birds. In late winter/early spring, goldfinches undergo a partial molt which lasts only a few weeks and affects feathers on the head and body but not the wings and tail. During this time the grayish feathers of the male goldfinch are replaced with brilliant yellow and gold. Females also may look more colorful, but their feathers are still dull by comparison. However, abrasion is also at work. Since the partial molt does not include wing feathers, these older feathers continue to abrade, and by late summer, the edges of the buffy or white wing bars disintegrate, such that the wings look almost all black. Check out the slideshow here for a month-by-month view.

American Goldfinch, early alternate plumage   Ann Pacheco/Audubon Photography Awards

American Goldfinch, late summer alternate plumage  Karen Brown/Audubon Photography Awards

American Goldfinch, basic plumage  Barb D'Arpino/Audubon Photography Awards

Birds with basic non-breeding plumage that are sometimes seen in winter in the Chicago area but aren’t as easily viewed from one’s window include the Common Loon, the Yellow-rumped Warbler, and the Chipping Sparrow.

In late summer/early fall the Common Loon molts its alternate or breeding plumage, losing the distinctive black and white feathers covering its body, including the checkerboard feathers on the back and the patterned necklace, in exchange for dull grays, browns, and whites.

Common Loon, alternate plumage   Derrick Jackson/Audubon Photography Awards

Common Loon, basic plumage    Mike Lane/FLPA/Minden Pictures

When the Yellow-rumped Warbler molts in late summer, it loses most of its striking colors. The vibrant blues, blacks, and whites are gone, but some of that distinctive yellow is kept. You could easily mistake this warbler for a sparrow if you miss the small yellow patches on the side of the body--until you see the rump with its conspicuous bright yellow patch.

Yellow-rumped Warbler, alternate plumage Megumi Williamson/Audubon Photography Awards

Yellow-rumped Warbler, basic plumage  Fran Morel/Macaulay Library

In late summer, adult Chipping Sparrows start molting into basic non-breeding plumage, exchanging the bright red of the cap and the black of the eyeline, for brown.

Chipping Sparrow, alternate plumage   Jesse Gordon/Audubon Photography Awards

Chipping Sparrow, basic plumage    Roger Baker/Audubon Photography Awards

Some birds seen in the Chicago area are typically here only with their winter plumage, as northern Illinois is part of their wintering grounds. Snow Buntings show up in October, already in their basic plumage of white, buff, brown and rusty tones. The female and male Snow Buntings that can be found in Chicago look much alike. In North America, these birds begin arriving in mid-March on their high Arctic tundra breeding grounds, where being primarily white-colored makes sense. However, the much-altered plumage of the breeding male is not the result of molting. The males actively abrade their plumage by rubbing it on the snow, producing a white and jet-black plumage by April, when breeding season begins.

Snow Bunting, alternate plumage  Debra Herst/Audubon Photography Awards

Snow Bunting, basic plumage   Gord Smith/Macaulay Library

Winter birding can be more challenging than the rest of the year. Numbing temperatures aside, the colorations of many birds become less vibrant, less distinctive. But these challenges can make it all the more rewarding when a somewhat nondescript bird is successfully  identified. So bundle up and enjoy our winter birds!

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