With wildfires raging once again across California, Oregon, and other western states, it’s easy to be overcome with despair. The damage, loss of life, and suffering have been immense. Blackened lands and smoldering trees testify to fire’s destructive power, and we see it as an enemy.
Yet wildfires, even those raging this summer in California’s Sierra Nevada Range and in Oregon’s Cascade Range, are also beneficial, playing a vital role in keeping ecosystems healthy. Numerous animals—including several species of woodpeckers, such as the black-backed and the red-cockaded—can’t survive without the fires that create perfect habitat for them.
For red-cockadeds, that means low-intensity blazes that periodically burn away the understory. Black-backeds, on the other hand, need fires of high-intensity, such as those burning this year in California’s and Oregon’s mountains. But they also want areas of green, unburned trees, which may be difficult for some of the birds to find this year. (Read more about how recent fires may be too devastating even for black-backed woodpeckers.)
To our eyes, such a fire-swept landscape “looks very stark,” says Rodney Siegel, a wildlife biologist and the executive director of the Institute for Bird Populations, a non-profit organization dedicated to studying and monitoring bird populations, in Petaluma, California. “But to black-backed woodpeckers, it looks like home.”
Indeed, Siegel and other experts say woodpeckers are a sign of a healthy forest, with a rich diversity of animals and plants. The longleaf pine forests that once stretched from Texas to New Jersey used to echo with the hammering of red-cockadeds, but beginning in the 1700s, overharvesting—compounded by suppression of natural fires—put the birds on the path to extinction.
By 1970, their numbers had fallen from nearly two million to no more than 10,000, prompting the United States Department of the Interior to add the red-cockaded woodpecker to the fledgling federal Endangered Species List. That required the U.S. Fish and Wildlife Service to develop and implement a recovery plan to protect this cardinal-size bird, which is named for the male’s red ribbon-like stripe above a white cheek patch.
Now, 50 years later, the Fish and Wildlife Service estimates that there are more than 14,000 red-cockaded woodpeckers in 39 recovery populations across 11 states and that 75 percent of 20 of these populations have reached the service’s “objectives.” The woodpeckers are joining a special group of animals—including gray whales, gray wolves, and Yellowstone grizzly bears—that have gone from being nearly extirpated to likely having a viable future.
Aaron Valenta—the Fish and Wildlife Service’s chief of restoration and recovery programs for the southeastern U.S.—says his agency is rewriting its recovery plan for the red-cockaded woodpecker and intends to publish a proposal sometime this fall to remove the bird from the Endangered Species Act list.
“It’s an incredibly exciting step,” he says. “Twenty years ago, there was no question this bird was going extinct. Now, it’s a recovered species. It’s just amazing!”
The birds’ ongoing rehabilitation owes in large part to recognition by forest managers that controlled fires in the remaining forests are important because they help protect the longleaf pines the woodpeckers need for food and shelter. Another important contribution—by scientists and the Fish and Wildlife Service—to their gradual comeback has been the creation of artificial nesting holes.
“Woodpeckers are ecosystem engineers,” says Teresa Lorenz, a research wildlife biologist with the U.S. Forest Service’s Pacific Northwest Research Station, in Olympia, Washington. She has tracked black-backeds in the forests of the Cascade Range. “Many small animals, from chipmunks to flying squirrels to mountain bluebirds and wood ducks, compete for the woodpeckers’ vacated nests because they are so protected from the elements and other predators. We wouldn’t have swallows, swifts, or bats without woodpeckers.” (Learn more about other animals that are also ecosystem engineers.)
Thriving and recovering forests in most of North and South America, and much of the world, need these birds to help maintain their overall biodiversity. (There are 180 woodpecker species in all, but none in Australia, New Zealand, Madagascar, and Antarctica.) Several North American species—including red-cockaded, black-backed (see illustration above), Lewis’s, and white-headed—need their forests to burn periodically.
Red-cockadeds require low-intensity fires, those typically caused by lightning strikes, to sweep away the undergrowth beneath longleaf pine forests, while Lewis’s and white-headed, found only in the pine forests of western North America, need higher-intensity fires to create a mosaic landscape of dead, standing snags and unburned, green trees. Black-backeds are also found only in those pine forests, but they have a range that stretches from the West to the Midwest, Alaska and across Canada’s boreal forest. These woodpeckers too need hot fires—but primarily for attracting the fire-chasing beetles they eat. (The beetles are so well adapted to fire that they have special heat-detecting sensors and lay their eggs in still-smoldering trees.)
“Where you have more woodpeckers, you have a greater diversity of habitat types and more bird and mammal species,” says Kathy Martin, an ornithologist at the University of British Columbia, in Vancouver, Canada, and a woodpecker specialist. “In North America, 90 percent of the cavities woodpeckers make are eventually used by other species.” By providing housing for animals that disperse seeds, such as chipmunks and squirrels, woodpeckers in the southeastern longleaf pine forests help maintain native plants, including wire and bunch grasses and running oaks.
As the red-cockaded woodpeckers’ population declined, so did the number of abandoned cavities—and likely the variety of animals that depend on them for shelter. Scientists don’t know how many species lived in the hollows, but in recent years, they’ve found some 27 vertebrate species and numerous invertebrates in them—this despite the woodpeckers’ reluctance to give up their homes.
Indeed, their cavities represent something akin to human wealth. They labor over them intensively, spending as long as 13 years to create a single hollow, and passing them down to their descendants. So it’s not surprising that they’re choosy about where and in which trees they carve their niches.
The building work is particularly arduous because unlike all other woodpeckers, red cockadeds drill their cavities in living, not dead, trees. They need trees at least 75 years old and of a sufficient diameter to accommodate a hollow. The pines should be growing in an open forest, without oaks or other hardwoods crowding the canopy—the kind of landscape that a rapidly burning, low-intensity wildfire creates. (Related: Why don't woodpeckers get headaches?)
The birds need several such trees nearby, because they’re clan-oriented and must drill separate hollows—a “cluster”—for dad, mom, and at least two male chicks, who help raise the next clutch. Juvenile females typically disperse to find a mate and start their own families. The average cluster covers about 10 acres, but the birds forage across some 200 acres, hunting for their insect prey only beneath the loose bark of pine trees.
Scientists don’t know how a red-cockaded male chooses trees, but apparently he can determine which ones have some interior fungal decay because those are the pines he begins to drill, typically doing so about 100 feet above the ground. All the family members then join in the excavation. First, the woodpeckers drill through the resinous sapwood, stopping occasionally to let the sap build up on the exterior, which forms a protective plate around the two-to-three-inch-wide entry hole.
When they reach the rotting heartwood, the birds follow its contours to carve out a nesting chamber that may be four inches wide. They also bring other wood-decay fungi into the cavity to further soften the interior, always working within inactive hardwood so the cavity remains free from resin that could trap the birds. They drill additional holes—“sap wells”—above and around the main cavity, creating a steady flow of resin on the tree’s trunk to deter rat snakes, the red-cockaded’s main predator. The holes don’t kill the trees but actually help rid them of insect infestations.
The female lays the eggs in the male’s cavity but sleeps in her own hollow; she returns each day to help incubate the eggs and later feed the chicks.
“A pair will use those cavities their entire lives,” says James Garabedian, a research wildlife biologist at the Forest Service’s Southern Research Station, in Asheville, North Carolina. (Very little is known about the red-cockadeds’ lifespan, but one in North Carolina lived for 16 years.) He adds that when the parents die, one of their male chicks will move in. He and perhaps even his descendants will use the hollow “as long as the tree lives.” Indeed, scientists have recorded some red-cockadeds using cavities for more than six generations, some 30 years.
Today, red-cockaded’s preferred trees are found on a mere 3 percent of their original range, but the birds seem to be on a slow path to recovery thanks to several new management tools, including controlled burns and artificial cavities.
Red-cockadeds won’t carve cavities in pines where the understory is tall and dense. Before Europeans arrived in North America, this was never a problem because fires—either sparked by lightning or intentionally by Native Americans—regularly swept through the understory. The pines’ thick bark protected them from being damaged, and they often lived 300 years or more.
“Now we have to remove that understory,” Valenta says, “by chopping it out or doing controlled burns.” (This was mandated by the Fish and Wildlife Service’s 1985 Recovery Plan for the Red-Cockaded Woodpecker.) The result is an open, park-like landscape that he and others say is visually appealing, perfect for red-cockaded woodpeckers and helpful to the region’s many native plants.
Although efforts are underway to restore longleaf pine forests on both public and private lands, it’s simply not possible for enough trees to grow to an advanced age in time to help the woodpeckers. Even after the birds were listed as endangered, their populations continued to decline.
Then, in the late 1980s, Jeff Walters, a biologist now at Virginia Polytechnic Institute and University, in Blacksburg, came up with an idea to assist the birds by making artificial nesting holes. One of his students, Carol Copeyon, carried out the plan. “She invented a technique to make a cavity in a living pine without killing the tree,” Walters says. (Copeyon did not respond to efforts to reach her.)
Copeyon drilled 20 artificial nesting holes in pines in North Carolina’s Sandhills. Within a year, red-cockadeds had moved into 18 of the human-made cavities. Her method received a boost after 1989, when Hurricane Hugo flattened nearly 90 percent of the longleaf pines in South Carolina’s Francis Marion National Forest. In that one storm, the forest’s woodpeckers (475 breeding pairs) lost nearly all their homes. To help them recover, the Forest Service drilled some 2,800 cavities, while the woodpeckers hammered out more of their own. Last year, the Fish and Wildlife Service counted 5,800 cavities and 512 clusters of red-cockaded woodpeckers in the recovering forest.
“It’s such a simple and effective technique,” Garabedian says, recalling the sight of a woodpecker moving into a cavity he’d drilled only 10 minutes before. “If you build it, they will come.”
Conservationists agree that red-cockaded woodpeckers are in better shape now than they were in the late 20th century, but some say it’s too soon to remove them from the Endangered Species List.
Jerome Jackson, professor emeritus of ornithology at Florida Gulf Coast University, in Fort Myers, and Mississippi State University, in Starkville, has studied the woodpeckers since the 1960s and was the team leader on the Fish and Wildlife Service’s first recovery plan for them, in 1972. He worries that the revised plan, which relies on artificial cavities and moving birds into new habitats, won’t achieve the original goal of establishing “a self-sustaining, natural population.”
The woodpeckers also need corridors of pines linking the remaining old growth stands, Jackson says, so that their populations aren’t fragmented--a goal of the original plan. And they’re dependent on these pines for food. “They need those old-growth trees with the loose bark where they can find insects and spiders.”
“It’s a sad thing. They’ll start going downhill again in spite of what’s being said,” he predicts.
Biologist Jeff Walters, though, is optimistic, noting that a high percentage of red-cockadeds’ populations are increasing. “They’re still dependent on management—they need those artificial cavities. But as the forest gets old enough, they won’t. But they will always need prescribed burns,” he says. Without those, their numbers will go right back down. “They are a fire-dependent species.”
Meanwhile, in California and Oregon, black-backed woodpeckers are likely already flying into the newly burned high-elevation forests in pursuit of fire beetles—a cycle of life that endures despite our human tragedies.