From afar, I can see something is different, out-of-place, not right. Concerned, I jump on the Kawasaki Mule, motor down the burn break/trail through the tallgrass prairie, and stop at the edge of the oak savanna. Off the Mule now, walking briskly through the savanna, I reach the area of my attention. Hidden from a distant view, but clearly visible now, is a large American elm tree snag (standing dead tree) lying prone on the ground and broken in several pieces. Arguably the most important tree in this little savanna, one that has provided a successful nesting site for many generations of the at-risk red-headed woodpecker, is now reduced to a pile of rubble!
Staring at the fallen snag, my mind chasing memories around in my head before finally catching one of them, I think of its short but productive life.
The snag began its “life” a decade ago when the American elm tree died of Dutch elm disease (an invasive fungus unknowingly introduced to North America in the 1930s). Shortly after its death, many species of insects find shelter and food in the bark and inner layers of the dead tree. With the insects come the predators such as downy woodpeckers, nuthatches and brown creepers, scampering up and down the tree trunk, shifting through the flaking bark, looking for their prey. Over time, sheets of bark pull away from the trunk, and species such bats, moths, tree frogs and spring peepers find refuge from the elements and predators under the hanging sheets of loose bark
After standing a few years, the bark now fallen, wood-decay fungus works away in the moisture-laden areas of the trunk, and many species of woodpeckers begin excavating holes. First, shallow penetrating cone-shape holes in pursuit of insects, but later complete nesting cavities as the wood becomes a bit more punky (wood broken down from decay). As time passes, holes of all shapes and sizes appear. Small holes created by downy woodpeckers, to large oval holes created by pileated woodpeckers. It’s not uncommon in an aged snag to see dozens of holes, especially near the top.
These high-rise condominiums provide homes for many other species. Typically, an aggressive species like the red-headed woodpecker will not let any other woodpecker nest nearby, freeing up unused holes/cavities for species such as the white-footed mouse and the adorable southern flying squirrel. Many species of cavity-nesting birds that cannot build their own cavities, such as the black-capped chickadee, tufted titmouse, bluebird, house wren and great-crested flycatcher, rely on these unused woodpecker cavities to raise their young.
With a decade now past, roots softened from decay, the snag finally falls victim to high winds created by a violently oscillating jet stream as winter and spring battle it out for dominance.
This is the snag where the red-headed woodpecker first returned and nested immediately after we completed our oak savanna restoration project. And they have returned every year since, successfully raising many generations of red-headed woodpeckers in this old snag. Where will they nest this year? Fortunately, as part of our savanna restoration process, we created many additional snags, or, to use a more appropriate term, wildlife trees. Many of these “practitioner-created” wildlife trees are now well-seasoned and filling up with woodpecker excavated cavities. Opportunities for the red-headed woodpeckers, as well as countless other species that depend on wildlife trees, are plentiful in this “restored” oak savanna.
The absence of wildlife trees is often a limiting factor for many restorations. In these cases, nest boxes, cavity inserts (removing a section out of a live tree and inserting a nest box), and what we call “insta-trees” (anchoring a manageable section of a dead tree or an untreated soft-wood pole into the ground) are some of the techniques used to artificially substitute for the lack of wildlife trees. Artificial cavities have been very successful for some species, but tend to fall well short of the universal species appeal of a wildlife tree.
I vacantly focus on the wildlife tree’s broken and twisted carcass. Saddened by its demise, but grateful for all that it has revealed to me through the years. While it will no longer provide homes for our aerial friends, ground-dwelling life such as centipedes, millipedes, snakes, toads, chipmunks and others will now take up residence. I find comfort in knowing that nature is not static, and life flows and ebbs in time-proven sustainable processes. Nonetheless, I will miss this old wildlife tree.
Goodbye, my fallen friend.