Thoughts on Forest Birds and Big Trees

Old growth community at The Cape Research Natural Area

by Steven D. Faccio

I just completed my Forest Bird Monitoring Program (FBMP) survey at The Cape, a Research Natural Area on the Green Mountain National Forest in Goshen, VT.  This was my 20th year doing point count surveys at The Cape—a spectacular old growth forest on a steep, west-facing slope—and I never seem to get tired of the place. Oh, there are plenty of reasons to find someone who lives locally to survey the site.  There's the 3:15am wake-up call, the hour-long drive, the 40-minute hike culminating with a gnarly bushwhack up a steep, 35-degree slope covered with stinging nettles, not to mention the treacherous footing which always results in at least a few inadvertent falls on each visit. 

But then there are the trees.  Huge, old growth sugar maples, white ash, and yellow birch—many as big around as a compact car, some with burls the size of tractor tires.  The trees keep me coming back every year.

I’ve been visiting this place twice a year since 1993 and have come to know many of these trees, as much as anyone can “know” a tree.  There’s the 30-inch diameter sugar maple near Point 2 with rough, lichen-coated bark, and large, buttressed roots covered in green moss.  There’s the massive yellow birch that I sit upslope from when I survey Point 3 so I can admire its large bulbous burl and keep an eye on the dark cavity that’s 10 feet off the ground, always hoping that I might catch a glimpse of whatever wildlife is sheltered within. 

There’s the black cherry that I first found a couple years ago on my way out of the study area.  It’s not up on the steep slope, but on the flats at the bottom, where all the nutrients from above get washed down to just before spilling into the beaver wetland.  The lone cherry is over two feet in diameter and nearly straight as an arrow for 60 feet before the first branch leaves the trunk. Although the tree’s economic value as a marketable sawlog must be significant, to me it pales in comparison to its significance as part of The Cape’s “big tree community.”

But the tree that holds the greatest significance for me is the huge white ash between Points 3 and 4.  Even though I know that it’s there, I’m always a little taken aback by its sheer size and height—like a towering mast from a great sailing ship in a sea of knee-high jewelweed.  Since learning about the threat posed by the emerald ash borer however, I find myself pausing at the ash each time I pass by.  This year, to get a better sense of its girth, I embraced the tree.  My arms didn’t come close to reaching half-way around the trunk, which is covered in thick grey bark, deeply furrowed into vertical ridges, some an inch deep and twice that wide. 

The ash reminds me that our forests are at a critical threshold.  The combined threats of introduced pests, including the emerald ash borer, hemlock wooly adelgid, and Asian longhorned beetle, along with the effects of climate change, are bound to alter our forests as we know them.  How will these changes, including the northward advance of southern tree species and the loss of ash and hemlock, affect wildlife populations?  As hemlocks turn brown, will the Black-throated Green Warbler’s ubiquitous, “zee-zee-zee, zoo-zee” go silent?  And what will become of the hemlock looper moth?

Clearly we can only speculate on these questions.  But with each passing year, long-term datasets such as VCE’s Forest Bird Monitoring Program become ever more valuable.  Having a 25-year baseline dataset about bird populations across Vermont will, at the very least, enable us to better understand how changes to the forest impact bird communities.  We’ve lost tree species in the past—American chestnut is gone and American elm is greatly reduced and short-lived—but we don’t know if their demise had any trickle-down effect on wildlife populations because we didn’t have baseline data with which to compare changes to.

The Cape is dynamic place—trees blow down in wind storms every year due to the steepness of the slope, while others die from insects or cankers.  One huge sugar maple near Point 1, which was apparently healthy when I started surveys in 1993, is now a standing, hollow snag.  While I don’t mourn the loss of the sugar maple, I’m bound to feel differently if the great white ash succumbs to an insect pest that we introduced.