The wide brown trunk of an ash tree in front of my house makes a good backdrop for assessing the density of falling snowflakes, their potential impact on the ski trails, and the unique beauty of a particular storm. While gazing at it last week, a bit of the bark began to move. The optical illusion lasted only a second before I recognized the small oval of brown-and-white patterning as a bird.
Brown creepers are cute little bits of camouflage with white bellies. This one moved upward in staccato motions, a bit to the side, around to the back, back to the front, and up some more. Pausing, the bird used their thin, downward-curving bill to explore a bark furrow. Perhaps they had spotted an overwintering insect larvae or antifreeze-protected spider for their lunch. Near the limit of my view out the window, the creeper suddenly launched off the tree and fluttered downward toward another tree trunk, out of sight.
Chickadees taking turns grabbing sunflower seeds at my feeder distracted me for a second, until movement at the base of the same tree again caught my eye. The brown creeper (or their mate?) was spiraling upward again. Apparently, there are enough crevices in a big tree like this that it pays to make many trips around the trunk.
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| Can you see the long claws and curved beak on this brown creeper? Photo by Emily Stone. |
The creeper hopped with both feet at once, and I knew that their curved claws were gripping tight. Their long, stiff tail braced against the bark. Just above a knothole, the creeper paused again and probed excitedly in a crevice until a flurry of motion brought a red-breasted nuthatch to that spot and the creeper flew off. The nuthatch circled, probing in the bark with their long, straight beak. Thief!
Having cleaned out that crevice, the nuthatch continued foraging downward on the trunk. Nuthatches are also known for their agility in navigating tree trunks, but whereas creepers go up, nuthatches specialize in going down. They are assisted by one backward pointing toe with a long claw on each foot. Nuthatches can hop in every direction, though, and even dangle on the twig tips with acrobatic chickadees. Their very short tail stays out of the way.
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| Nuthatches are known for climbing head-down, but are pretty versatile. Photo by Emily Stone. |
The first lesson in my first ornithology class back in college used these two birds as an example of how to identify a species by their behavior. Brown creepers hop up a tree, then fly down to the next one. Nuthatches walk down and then fly back up.
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| Classic nuthatch behavior! Photo by Emily Stone. |
Although both nuthatch and creeper populations are thought to be stable, I see and hear many more nuthatches while I’m out in the woods. This is partly due to their brighter colors and louder calls. Nuthatches shout their distinctive yank! yank! yank! pretty consistently as they feed in mixed flocks with chickadees and woodpeckers. Brown creepers, on the other hand, have thin, high voices that are easily lost among the contact calls of other birds. I’m not the only one who tunes out their songs. A study published in The Canadian Field-Naturalist journal in 2020, discovered that brown creepers do sing in the dawn chorus, but it took an automated recording to notice them consistently.
It's not just that nuthatches are easier to see and hear. They are also far more numerous. There are almost three times as many red- and white-breasted nuthatches in the world as brown creepers! Perhaps this is because brown creepers have some unique habitat requirements.
Brown creepers need forests with large trees for both foraging and nesting. They build their nests behind pieces of loose bark, which are more common on large trees that are dead or dying. Big trees also have deeper furrows for hiding the tasty insects and spiders that creepers prefer. Creepers occasionally eat seeds or suet, but rarely visit feeders. One study found that the gnarly bark of large yellow birch trees make good habitat in the East, while they are found in conifer forests in the West. These populations of creepers may actually be different subspecies, but physically they blend in with each other as much as they do the trees. It’s only through DNA studies that scientists are learning to separate them.
Nuthatches seem to thrive in a wider range of habitats and ages of forests. Nuthatches reuse old woodpecker cavities for nests, and sometimes excavate a hole themselves, but these can be in smallish trees. Both red-breasted and white-breasted nuthatches are much more likely to eat seeds than creepers, which expands their options to include bird feeders.
Happily, the greedy nuthatch didn’t scare away the brown creeper for long. As the snowflakes drifted down, the cute little bit of camouflage returned to the tree for another expedition up, lifting my spirits as they went.
Emily’s brand-new third book, Natural Connections3: A Web Endlessly Woven, is available to purchase at www.cablemuseum.org/books and at your local independent bookstore, too.
For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Winter Calendar is open for registration! Visit our new exhibit, “Becoming the Northwoods: Akiing (A Special Place). Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.
