Upside down is right side up for the nuthatch
Of the four North American species of nuthatches, Minnesota is home to two species — the red-breasted nuthatch and the white-breasted nuthatch, the latter being the most widespread of them all.
The other two species, the brown-headed nuthatch and the pygmy nuthatch, occur primarily in southern-eastern United States and western North America-Mexico, respectively.
Both of our Minnesota species of nuthatches range extensively across most of the United States as well as much of southern Canada and parts of Mexico. Both species that reside here in Minnesota are year-round residents, which make these birds notable among our wild birds given the long Minnesota winters. Thankfully nuthatches stick around all year to entertain us at our backyard bird feeding stations.
One of the many interesting behaviors typical of nuthatches is their habit of clinging upside down on tree trunks and limbs. Though other birds are nearly as acrobatic, like chickadees, woodpeckers, and brown creepers for example, only nuthatches inch their way down a tree headfirst in their search for food, whereas woodpeckers and brown creepers — usually — climb trees by working their way upward, headfirst.
And there's more. Nuthatches have exceptional spatial memories. In other words, these little birds are experts in remembering where they cache, or hide, their seeds and foodstuffs. Next time you watch your birdfeeder, take note what happens when a nuthatch arrives.
Like chickadees, they don't stay long for you to observe them. In the case of sunflower seeds, a white-breasted nuthatch will extract several sunflower seeds from the feeder before making off with one. What these birds are doing is literally weighing the seeds (other birds do this too).
Much like we mentally test the weight of a fruit or vegetable at the supermarket by hefting it in our hand before deciding on buying it, nuthatches are testing the weight of individual seeds to find out if what's inside is worth their time and energy. They do this quickly of course, rejecting seeds and dropping them to the ground below. Then, finding a suitable seed, they fly away with it.
What the birds do next with the seed depends on its hunger. If its mission is to save it for later consumption, the nuthatch will stuff the seeds into the crevices of trees, under bits of bark, etc., and will then return to the birdfeeder to do the same thing again and again.
If they are hungry you will discover how the nuthatch got its namesake. When a nuthatch wants to break open a seed's shell, it will secure the seed into the bark or crevice of a limb or tree trunk and repeatedly "hack" away at the seed's shell with its bill until it can extract the prize "seed meat" inside the shell.
Perhaps "nuthack" would be a more appropriate and understandable name. And regarding the birds' memory that I mentioned earlier, nuthatches have the extraordinary ability to recall its hiding places and, thus, its food.
During severe winter weather it is important for animals like nuthatches, gray jays, Clark's nutcrackers, chickadees, squirrels, weasels, foxes, and others, to be able to cache foods to eat and readily locate when environmental conditions become severe and when food becomes scarce.
Nuthatches hide seeds all day long and are able to locate a vast majority of their hidden morsels when necessary. So designed are nuthatches bodies for an upside down lifestyle, that the birds appear ill-equipped for upright mobility. They seem much more comfortable clinging upside down or underneath tree limbs or suet feeders than they do at almost any other position. Their bodies and behavior are especially adapted for exactly what they do best.
Looking out at my backyard birdfeeders, I'm reminded that I've some work to do. Twice a black bear knocked my feeders down late this past spring and so I quit feeding birds altogether for the remainder of the spring. I never did resume feeding. And while I'm confident that the neighborhood wild birds have been getting along okay without my handouts, I'm eager to begin feeding again so I can watch and listen to the local nuthatches, chickadees, and woodpeckers. I must admit, I miss them.
Worldwide, there are 25 species of nuthatches and their kin. Indeed, to be able to look outside and observe two species of these specialized little birds inching their way up or down and sometimes vocalizing their "yank, yank, yank" nasal-sounding calls — the red-breasted and the white-breasted nuthatches — is a delight to be sure, as we get out and enjoy the great outdoors.