There’s no doubt about it; we have had a winter this year. We’ve had snowy landscapes, frosty trees, frozen ponds, and birds flocking to feeders. While many birds migrate south to warmer climates, there are a few remarkable species that remain with us throughout the winter. These winter-resident birds form mixed-species flocks that patrol in search of rich food sources. Made up of primarily chickadees, titmice, nuthatches, and the token Downy Woodpecker, these flocks are the first responders whenever you fill your feeder, and the chickadees always lead the charge. Invariably, a Red-bellied Woodpecker is close behind, and the flurry of activity soon attracts the attention of the other troops out there. Before you know it, the Blue Jays arrive, a pair of cardinals wing in, and juncos start hopping around on the ground.
What I am describing is the typical scene outside my living room window every morning while I watch from my breakfast table. The cast of characters is always the same, and sometimes a House Finch plops itself unflinchingly on the feeder perch, or White-throated and Song sparrows join the juncos. The other morning, though, I had a new arrival. A Brown Creeper! No stranger to the mixed-species flock, creepers are well aware that the chickadees know where the good eats are. As I watched this tiny bird work its way up the trunk of the young oak from which my feeder hangs with its bounty of black-oil sunflower seeds, it occurred to me that the Creeper wasn’t there for the seed…
The cryptically plumaged Brown Creeper often goes unseen. Barely the size of a worn bar of soap, It blends in perfectly with tree bark, and it is a dedicated insectivore. It has a thin, down-curved bill that couldn’t crack open a sunflower seed to save a life. With daily sub-freezing temperatures being the norm for the past month and a half, I wondered what that little guy was subsisting on. Not counting the ladybugs and the Western conifer seed bugs persisting in my house, the world outside has been a frozen wasteland where surely no insects dare to venture. Right?
Wrong. The creeper and the universe seemed intent on teaching me a lesson. My reading habits can be described as ADHD-like. I have books scattered around the house, and I am reading them all. The one that happened to be on my breakfast table that morning was Doug Tallamy’s The Nature of Oaks. I had a cup of coffee to finish, so I opened the book up and was greeted by a picture of a Golden-crowned Kinglet, another winter resident that knows the benefits of hanging out with the local gang.
Dr. Tallamy recounts one of the studies of Bernd Heinrich (Heinrich & Bell, 1995). Heinrich is one of the finest scientists/writers of our time, and if you haven’t had the pleasure of reading one of his books, I suggest seeking one out to cap off your winter reading list! Mind of the Raven comes to mind if you need a recommendation. But I digress! Heinrich and Bell were dissecting kinglets that had been killed during the winter by window strikes in Maine. They discovered that their crops were jam-packed with caterpillars! Caterpillars that had been consumed the very same, freezing cold day they met their maker in the form of a plate glass window.
Turns out that while remaining invisible to our eyes, many species of moths, especially inchworms such as Alsophila pometaria, which bears the unfortunate common name fall cankerworm, spend the winter in their caterpillar stage. Inchworms feast on the green leaves of their host tree until the buffet table is empty, then simply stop eating for the entire winter. Crawling into bark crevices, snuggling deep into lichens, or simply freezing in place on a branch while doing their best impersonation of a twig — whatever strategy these tiny caterpillars use, they do their clandestine best to remain undiscovered by hungry birds. This is the food that Brown Creeper was looking for, and it’s not only creepers and kinglets that seek out these tasty morsels. Further reading revealed that all the birds in my roving mixed-species flock supplement their seed-heavy winter diet with insects. In fact, 50% of the chickadee’s winter diet that Tallamy (and myself) had always assumed to be granivorous is actually made up of insects!
As I closed my book and finished my coffee, I had much to consider. I had been allowed to see the world through a different lens. It’s not like I didn’t know creepers and kinglets were insectivorous; I just never looked much deeper than beyond my own joy of having one brighten my morning.
Bugs, however, are not everywhere. Bugs are where their native host plants are, and if the tree my feeder hangs from was a Kousa dogwood, rather than a white oak, I never would have seen that creeper. Even then, as I watched the chickadees flitting with fervor all over the oak’s branches, the nuthatches hopping down the trunk, the titmouse at the base, I began to understand it is not just the seed they are here for. Not all plants are created equal, and while many people do know they are necessary to produce insects, they make the mistake of assuming all plants produce insects. If that were true, we could plant plantations of Kousa dogwoods everywhere without the fear of creating relatively lifeless rows of trees, and erroneously call it a forest.
How much of my life have I spent underestimating the oak trees around me? Most of it. They are not merely stately sentinels of the landscape; they are life-support systems, teeming with hidden activity that often goes unnoticed. Even as an educated conservation biologist, with every new observation, I understand more and more. Doug Tallamy’s book resonated even more deeply now: Oaks aren’t just for the birds we see flitting about; they’re essential for the insects, the creepers, and even the fungi that play a role in keeping the entire ecosystem healthy.
It’s easy to take these things for granted, to focus on the more visible parts of nature — the eye-catching cardinals, the flashing blue of the jays, and even the raucous crows that are always present, always watching. But in reality, the oak’s quiet, invisible contribution is just as crucial. I took one more look out the window to watch the action, and the creeper was gone, off to conduct another scavenger hunt elsewhere. Sometimes, it’s the quietest, most unobtrusive members of the ecosystem who have the most to teach us.
It wasn’t just about the birds or the insects, but also how they find a way to persist even in the harshest of conditions. The Brown Creeper, like so many of its companions, had figured out how to survive when it seemed like the world was dormant. It reminded me that even in the middle of a cold, (moderately) snowy winter, life is still bustling — just beneath the surface, or in this case, just beneath the bark.
As I gathered my belongings and prepared myself for another day in the office, I felt an understated kinship with the often-overlooked creatures that quietly share our world. The chickadees and the titmice would come and go, as would the Blue Jays and cardinals, but the Brown Creeper — that tiny, almost invisible bird — had made its mark in my mind, while the work of two great scientists left me with a deeper understanding of the resilience and interconnectedness of the natural world.
If you would like to learn more about what you can do in your backyard to help allow nature to teach you lessons over breakfast, you can find out more about our Natural Neighbors program by clicking HERE. And while you are there, schedule a visit for us to come by and help start you on your journey! We will share our knowledge and resources at no cost to you and find many other ways for you to support biodiversity in your yard.
