The black-and-white warbler isn’t wildly difficult to ID by its plumage: it’s black and white—even the female. But there’s a lot more to say about this little songbird. Interestingly, the chickadee-sized bird carries the warbler name, but behaves more like a nuthatch. It forages from tree branches and trunks—like a red-breasted nuthatch—instead of on the ground. But, unlike nuthatches, or other tree-hugging species such as the brown creeper, a black-and-white warbler’s MO is to scale the tree’s trunk in both directions. First, they go up, then they go down, taking advantage of the buffet of insect and insect eggs that they can dig out from underneath the bark. Efficient.
Black-and-whites are also easy to ID because you’re likely to actually spot them in the first place. They’ll wander about on low tree branches, even at eye level, and they aren’t shy or prone to flying away if a human approaches. And, perhaps because males keep their flashy breeding colours (the bold, black-and-white back and sides, and black throat patch) longer than other warblers, they sing well into August. So, you’re likely to hear them: “weesee, weesee, weesee!” It sounds a little like a squeaky wheel, or the sound of somebody cleaning a window.
Although they eat from the trees, black-and-white warblers nest on the ground, usually at the base of a tree or between its roots, or occasionally on a stump. A low nest is a risk for a bird; ground-nesting birds, eggs, and hatchlings can fall prey to more predators. Nest location, coupled with more and more forest fragmentation—when logging and roads create open, exposed fringes of forest—could be one reason black-and-white warbler numbers have decreased by about a third since the 1960s.
Well, at least Mama warbler has a trick up her sleeve—one that she steals from the male killdeer. She’ll feign a broken wing and try to lure predators such as raccoons or garter snakes away from the nest. Papa plays a role too: he tones down his singing during nesting season to avoid drawing attention to himself, the missus, and the babies. High five for co-parenting!