On the wild side—March, 2011
by Tina Mitchell
Outside your window, a perky little bird moves up, down, and all around a tree trunk—sometimes even stopping upside down on a tree branch. (The photo to the right is not upside down—the bird is!) Moving headfirst down the trunk, it pauses to crane its head up and back, toward the horizontal, for a look around. Is it a woodpecker of some sort? Woodpeckers often move up and down a tree trunk, but not headfirst. And they all have stiff tails that they use almost as a 3rd limb propped against the trunk. This bird isn’t using its tail at all—just its strong, grippy little feet. (In fact, if you had this bird in your hand—which I certainly don’t recommend—you could see that its backward-facing toe—the hallux—is longer than most other perching birds.) Also, you rarely see a woodpecker completely upside down on a branch—at least not on purpose. This is a White-breasted Nuthatch, checking for insects or seeds in the crevices and furrows of the bark. White-breasted Nuthatches often store morsels on tree trunks and limbs, typically covering each with a piece of bark, lichen, moss, or snow.
Easily identified by its black crown and nape—looking rather like a dark Mohawk haircut—a white face and belly, and a blue-gray back, the lively White-breasted Nuthatch can be found pretty much anywhere in the U.S. that has trees. Taxonomists currently consider 3 separate groups of White-breasted Nuthatches—based primarily on differences in their calls. Birds in the eastern United States and Canada utter a nasal one-noted yenk. Those in the Interior West (where we fall) have a repeated 2-syllable call like yidi-yidi-yidi-yidi, and birds on the Pacific slope utter a high-pitched, drawn-out aaarn. (Honest—people write about these calls this way. It makes a bit of sense when you hear the different calls, but it looks pretty goofy on paper.) Habitats also differ across the groups. Eastern birds seem to prefer deciduous forests; Pacific area birds, oak woodlands. But in Colorado, White-breasted Nuthatches choose conifer habitats about 4:1 over any other treed areas—with breeding surveys reporting them predominantly in pinyon/juniper woodlands and open ponderosa forests. Every now and then, talk surfaces about declaring these groups to be separate species. But for now, they are all classified as White-breasted Nuthatches.
Their scientific name is Sitta carolinensis. Sitta comes from the Greek word for a nuthatch, a word originally used by Aristotle for pretty much any bird that pecked on a tree. (Hard to know how it came to be pinned to this particular tree-pecker, though.) The species name—carolinensis—derives from Latin, meaning “belonging to the Carolinas” since they were first found in the Carolina area. The common name of “nuthatch” arises from their habit of wedging a hard food item such as a nut into a bark crevice and hammering or hacking (“hatching”) it open with the bill.
White-breasted Nuthatches always nest in some kind of cavity. Since they can’t excavate their own holes, they have to get a bit creative in finding good spots—sometimes settling for nooks and crannies in twisted junipers. In our area, they will also happily nest in human-made nestboxes, although the 2 groups elsewhere in the country almost never do. In nestboxes on our property, we usually host 2 or 3 families of White-breasted Nuthatches each year. Generally the earliest cavity nester we have, they commence nest-building activities—investigating holes, laying in strips of vegetation as the base of a nest—as early as mid- to late March. You can see photos of some White-breasted Nuthatch nests and nestlings in our nestboxes here: http://wp.me/Ph4IP-dD. (If you’re not clicking from the electronic copy, be sure to type in capital letters as they appear!)
You can read more about this perky “upside-down bird” here: http://wp.me/P16Ptu-3G .