Identifying Orange-crowned Warbler and Tennessee Warbler

Wood warblers, as a group, are some of our most colorful and strikingly patterned birds. But there are exceptions, and one of the most notable is the Orange-crowned Warbler. It is a widespread bird found virtually throughout North America in certain seasons, but its simple appearance makes it easy to overlook.

The breeding range extends from western Alaska to Quebec and Labrador, south in the western mountains to New Mexico and Arizona, and south along the coast of Pacific to California. It winters mainly in the southern United States and Mexico, with some winters in southern Guatemala. In many parts of the southern states, it is the second or third most likely warbler to be seen in mid-winter.

Orange-crowned Warblers are much less numerous in the east than in the west. Although they occur as coast-to-coast migrants east of the Mississippi, they often elude birdwatchers during their migration. This is partly due to timing: in the east, they tend to migrate earlier in the spring and later in the fall than most warblers. Even as far north as the Great Lakes, their fall migration occurs primarily in late September and October. They often forage in brushy areas, even in stands of goldenrod, where birders may not be looking for warblers.

Their lack of obvious ground markings can also make them easy to overlook, especially in the fall when many other warblers also sport relatively drab plumage. The species most likely to be confused with the Orange-crowned Warbler, the Tennessee Warbler, is quite variable in the fall. It usually has a fairly plain face with a pale supercilium, or supercilium, somewhat more sharply defined than that of the orange crown. It is often dull yellow on the throat and breast, and has one or two very narrow pale wingbars. Its undertail-coverts, usually white, are sometimes washed with yellow. However, this area is never more yellow than the rest of the underside.

The Orange-crowned Warbler’s appearance varies with range. The duller olive-gray subspecies breeds throughout the north, from western Alaska to eastern Canada. In the interior mountains of western Canada and the western United States, it is replaced by another breed that looks a little brighter. Along the Pacific coast, from southern Alaska to California, a fairly bright yellow subspecies takes over. Despite the overall color variation, the same basic markings apply throughout, as shown and described in the accompanying photos and captions.

Oh, and as for its English name, males and most adult females have a patch of orange feathers on the crown, but this patch is largely hidden by the surrounding olive or gray feathers. You’re most likely to see it on adults in mid-summer when their feathers have worn down, revealing the underlying color. It’s an intriguing thing to look for but it’s not a useful point of identification.

Orange-crowned warbler, adult. February in Hidalgo County, Texas

Like many other warblers, adults in most populations undergo a complete moult, replacing all feathers, in late summer on the breeding grounds. At the end of winter, they have a limited moult, mainly replacing the feathers of the head. When the head feathers are worn down (in mid-summer and sometimes mid-winter), the orange crown patch is more likely to be visible; a few orange feathers can be seen on this February bird wintering in southern Texas. Although this individual is near the dull and pale extreme for the species, its undertail coverts are still distinctly yellowish, not white, and at least as bright as any other yellow in the bird.

Tennessee Warbler, adult. April in Galveston County, Texas

The Tennessee Warbler’s underparts can vary from bright white in spring birds to bright yellow in some birds in fall, but in the latter the yellow is concentrated on the throat and chest. The undertail-coverts are usually white. Sometimes they are tinged with pale yellow, but in these cases they are much paler than the chest. The center of the back is conspicuously green in all plumages, and the face always shows a fairly distinct dark eye-ring and pale supercilium; the bird in this photo is near extreme low. The shape of the bird is also helpful: the Tennessee Warbler has a significantly shorter tail than the Orange-crowned Warbler, and this is quite noticeable with a little practice.

Orange-crowned warbler, adult. April in Riverside County, California

The subspecies bright, much brighter yellow on average than other Orange-crowned Warbler populations, breeds in the Pacific Coast region from southern Alaska to California. On migration it spreads further east, commonly appearing in Arizona and straying as far as the Great Plains. Despite its brighter color, it resembles the other subspecies in terms of ground markings. Its wings and tail are very simple, and its face consists mainly of a narrow, broken eye-ring, usually yellow. The fuzzy streaks on the sides of his chest are often hard to see. Another subspecies, dirty, of the Channel Islands and locally on the coast of southern California, is similar but darker. It shows thicker dark streaks below, including on the undertail-coverts.

Orange-crowned warbler, adult. May in Anchorage, Alaska

The brightest and dullest subspecies of orange-crowned warblers are both found in Alaska. The general race hidden breeds from extreme western Alaska south to Canada to Atlantic coast of Labrador and Quebec. It is a relatively dull olive gray form like the one seen here. The bright yellowish bright is widespread in southeast Alaska and extends north almost to the Anchorage area. This bird, photographed in Anchorage, looks typical of the dull east hiddenbut intermediate birds can be found nearby, and they might suggest the appearance of the breed orester from the mountain to the west. Trying to apply subspecies names to birds in the field is difficult, but monitoring such variations can add interest to birding trips.