Fire and Birds

By David Cronenwett

In the summer of 2007 I led a hike on the Lewis and Clark Forest down the six-mile long Box Canyon, through which the North Fork Teton River flows. The east-west trending, glacially cut chasm is, as the name suggests, steep-walled with essentially no way out save the river corridor. The forest was dense with small diameter conifers and if memory serves, the understory contained few species of flowering plants or shrubs. There were no notable bird sightings. Our small group though was thoroughly enjoying themselves; this route involves multiple stream crossings and on that day of searing 90-degree heat, these were a fun and welcome reprieve.

Stopping for lunch on a bend in the river, a look up and over the high ridge revealed an enormous white column of smoke obscuring much of the visible sky. This impressive, seemingly close and imposing sight made some of the walkers question the sanity of traveling in a canyon like this with essentially no bailout options. We were witnessing the impressive smoke column of the Fool Creek fire; a lightning-ignited burn that began deep in the Bob Marshall backcountry a few weeks before. The fire was still a safe distance out but warm summer winds had driven it eastward, toward the Front and potentially right into the drainage where we were now sitting.

We mused about the ecological role of fire on this landscape while shaded in cool repose. The Teton’s emerald waters churned before us and an occasional dipper cruises by. As expected, there were a variety of comments from hikers about that ominous mass of smoke to the west, most trending in the “they do try to put those out, don’t they?” category. This particular fire began far enough in the Wilderness that it was going to be left alone to do its thing… up to a certain point. Once past a certain comfortability threshold, where it could veer into the more populated canyons and prairie, land managers would move heaven and earth to contain or deflect it.

As our hike concluded by the North Fork bridge, we were greeted by Forest Service personnel who, after asking about our walk, promptly informed us that the Box Canyon, and the rest of the forest was closing immediately to public entry for safety reasons. I later realized we were the last group of people to see that canyon before Fool Creek bore down on it with tremendous fury.

When I revisited the North Fork that September, after “season ending” rain-snow events had extinguished the blaze, there were still pockets of burning logs and debris here and there across an almost unrecognizable moonscape. The topography of the area had created a chimney-effect, probably increasing the fire’s intensity. What was astonishing were the shoots of green vegetation already breaking through ash and charred soil, some deer and moose tracks and a sassy pine squirrel, in the midst of complete devastation, barking at me from a burned snag and very much alive. What was also obvious was a virtual absence of avian life.

Over the next two seasons, it was difficult to find more than a few robins in the burn zone; the fire in this area had been in the “stand-replacement” class, meaning all vegetation was completely torched. Wildfires burn in all of Montana’s landscapes at varying intensity and timescales and play a critical ecological role. Depending on elevation, moisture, climate and fuels, a wildfire may only burn off the understory layer, be “mixed-severity” or stand-replacing. Birds respond to fire in a variety of ways, but the rule of thumb is that there will always be winners and losers. Species that rely on dense, closed canopy forests like Northern Goshawk will simply have to go elsewhere after a severe forest fire event. Likewise, “foliage gleaners” such as mountain chickadees and ruby crowned kinglets will be out of luck for some time to come. On the other hand, species that could immediately benefit in the post-fire landscape are ones that are considered relatively rare today, especially cavity nesting/wood foraging birds like Black-backed and Three-toed Woodpeckers. Black-backs are particularly interesting because they seem highly dependent on burned forests, arriving not long after the flames retreat to gorge on beetle larvae that attack dead or fire-stressed trees. Mammals of course, respond to fire as well; boreal species like pine marten are usually displaced by it, but grazers and generalist omnivores (bears) tend to thrive.

The explosion of plant diversity along the North Fork was rapid and breathtaking; previously stunted aspen clones grew and expanded with vigor and uncommon wildflowers like Bicknell’s geranium and dozens of others proliferated across the landscape. But the lack of birds was troubling to me and I began to question whether any would return here at all. Everything changed that third summer though; the vegetation seemed to have returned enough to support a critical mass insects and rodents, and the birds quickly followed. Most notable were the raptors particularly American Kestrels, Red-tailed Hawks and then, the unbelievable discovery of breeding Northern Hawk Owls, known to thrive in recently burned forests, but very rare in Montana.

Because of a century of fire suppression and the fuel-loading associated with it as well as complex factors like climate change, wildfire behavior on western forestlands can be unpredictable. But what is certain is that wildfire, this most important element of disturbance and change on the landscape, isn’t going away any time soon. Fire exclusion over the decades has created an artificial abundance of some birds, and a reduction or complete absence of others. The healthiest state of affairs would be to have fire play its natural, recurring function where possible. Tinkering with the fire regime has had profound effects on forest and range ecology, and solutions to righting the situation can be difficult. If I’ve learned anything about wildfire though, it is that sooner or later, no matter what we do, it will come.

As my exploration of the nearly 60,000-acre Fool Creek burn expanded beyond the North Fork drainage, I realized that while large swaths of land had been nuked, others burned with less intensity, creating a classic “mosaic” pattern. We have a strong penchant for living trees and expansive, green forests. We tend to view fire only as destruction and generally do not value the ecological and aesthetic changes it bestows upon places we love. But it may be time to broaden this view; I’m sure the Black-backed Woodpeckers and Northern Hawk Owls would appreciate it.