When you say ‘warbler’, most people think of small bright birds moving through trees full of leaves. And that makes sense- most warblers are encountered in warm weather. They are a highlight of the spring migration, when their plumage is at maximum color. Some species summer over in Ohio, raising families before heading south in the autumn.
However, there is one warbler that makes Ohio its cold-season home. This bird is not here because of injury or illness that prevents it from migrating- it surprisingly copes with the cold weather as a matter of course. Yes, some of these birds like Ohio winters!
The Yellow-Rumped Warbler is Ohio’s only regular winter warbler. In the summer, it nests as far north as Alaska’s coniferous forests; in winter, it travels south as far as Central America. But it can and does winter as far north as the Canadian border area, including Ohio. How can it winter in such cold locations?
This bird is one of the larger warblers, which helps it retain body heat. But its most adaptive feature is its ability to digest waxy berries such as bayberry or wax myrtle- the latter is the berry that gave this bird the name of Myrtle Warbler (before ornithologists reshuffled a couple of species and combined them into one). While they eat insects when they are available, berries and even occasional seeds are consumed- a rather un-warbler-like thing to do. But this versatility in their diet allows them to winter in such places as Ohio.
In cold weather, the males and females look very similar- brown and white with yellow patches on their rump and beneath their wings. By spring migration, the males are wearing a more colorful outfit of blue-gray, black and white to complement their yellow patches. Both sexes have an incomplete white eye ring and white wing-bars. The underside of the tail is white, too.
In spring and summer, like other warblers, they pair off to raise nestlings. But in the winter, like many other birds, they tend to flock together. I’ve seen them singly, in pairs and in small groups this winter- it often seems that they are associated with mixed feeding flocks of other species. Interestingly enough, there is a warbler hierarchy with some species higher or lower on the ‘pecking order’ when they feed together in warm weather. But now, in winter’s cold, there’s less species around to squabble over berries.
This bird makes a distinctive call which helps in its identification. The sound is a short sharp hollow-sounding ‘check’, which, with a little practice, can be readily distinguished from sparrow calls.
Yellow-Rumped Warblers are a common species, so they’re not difficult to see. They seem to thrive on their varied diet. I always enjoy running across them in the depths of winter, giving a small glimpse of the colorful warbler season to come next spring.