A recent question from a reader: How are the major wildfires in the West affecting birds, especially migratory species?
This is an excellent question and the search for an answer indicates that we may be in uncharted waters on this issue. Birds can fly away from danger and they've dealt with wildfires for eons. But this year may be the start of something different.
Both resident and migrating birds will fly out of a forest or grassland as smoke begins to build, but where will they land? The fires currently burning in the West are larger than any we've known before and there are more of them, bringing devastation to a wider landscape. And then there's that thick blanket of choking smoke, as well.
The areas where birds have traditionally found shelter and food to fuel migration, their stopover sites, may have become dead zones. And there are fewer alternative sites, as humans continually encroach ever further on wild areas.
By mid-August, California was just seeing the start of songbird migration, with birds heading for their usual stopover spots. According to Audubon California's Andrea Jones, when birds reach a burned area, they'll probably keep on flying. But if they've had to start migration before they've had a chance to put on a good layer of fat, the deficits begin to intensify.
"If we remove links in the chain, birds will have difficulty completing their journeys," she noted.
Consider, too, that the fires broke out just as young birds fresh out of the nest were beginning to learn needed survival skills, and this important period was probably cut short.
There's a compounding factor here, as well. The West has been under a severe drought for five or more years, a major stress to birds (and all other wildlife). Birds must fly farther to find water and work harder to find the insects, seeds and berries they need to eat, and these may be scarce or even unavailable in burned areas.
Even areas that aren't in flames can be dangerous. Avian respiratory systems are very sensitive (there's a reason canaries were carried into coal mines a hundred years or so ago) and smoke inhalation can be harmful to birds. Add in high temperatures and many birds are highly stressed and vulnerable to respiratory infections.
These are broad outlines, because as a researcher at the University of Washington, Olivia Sanderfoot, says, "We know pretty much nothing about the long-term impact of smoke on birds."
As if things weren't dire enough, late August brought reports of a mysterious and unprecedented die-off of thousands of migratory birds in a number of Western states. Bird researchers are still looking into this, but the explanation may lie in compounding factors — huge fires driving birds to migrate early and interfering with visibility and causing migration-route shifts, while the smoke and heat impaired birds' respiratory systems. Another possible factor is an intense, early cold snap that hit the area, killing off the food that insect-eating birds needed.
The executive director of Audubon Southwest points to our warming planet to explain this kind of severe event.
"This is about abrupt changes in our weather patterns as a result of climate change," says Jon Hayes. "These things are going to cause long-term declines, long-term losses and they're going to be punctuated by big, scary events like this."
Not all fires are harmful to birds, and in fact, fire is a natural part of most healthy ecosystems. A number of species, especially woodpeckers, benefit from the insect life that quickly repopulates a burned-over area. But these new mega fires may be changing the rules of the game and leading to permanent changes in habitats, which almost surely won't be good for wildlife.
Back to the question: How are migrating birds affected by the West's wildfires? We seem to have entered a new era of longer burning seasons and larger and more widespread fires. We have to hope that birds have the time and space to adapt, if this is the new normal, before it begins to affect them at the population level.
St. Paul resident Val Cunningham, who volunteers with the St. Paul Audubon Society and writes about nature for local, regional and national newspapers and magazines, can be reached at valwrites@comcast.net.
