Surplus of “middle-aged” forests afflicts Northeastern songbirds
By BRANDON LOOMIS
Sometimes cutting down a tree is the best prescription for saving a fast-disappearing bird.
In New York, at least, where two-thirds of the state is forested and most trees are what ecologists would call middle-aged, there’s precious little young forest for songbirds that need it for nesting or foraging. Some of these birds—especially the golden-winged warbler, a 4 ½-inch summer visitor—are in steep decline. The warbler’s Appalachian population, stretching as far north as the Champlain Valley, has lost 66 percent of its members in 50 years. It is projected to lose more than half of the remaining birds in the next decade.
Bruce Cushing is managing his woodlot east of Lake George for commercial timber and bird habitat. Photo by Mike Lynch
With that in the back of his mind, Bruce Cushing bent over a downed beech in September, revving his chainsaw to trim the limbs for stacking to the side of his access path—an old skid road from the logging that preceded his purchase of the land. Later he would paint the stump with an herbicide, hoping to kill the spindly beech shoots that radiated from the parent tree and threatened to close the forest canopy around it.
His plan is to create a patchy mix of hardwoods, evergreens and shrubs on his hundred-acre woodlot on the Adirondack Park’s southeast fringe, east of Lake George. It’s a retirement project for the former railroad engineer, and he has the Audubon Society’s help in planning it. Beeches in particular are fair game, as a bark disease that afflicts them across the Adirondacks causes them to send up reinforcements that can quickly take over the forest because deer won’t eat them.
Just down the path from the beech he felled, Cushing craned his neck to gaze at the top of a tall but dying maple, gnarly and hollowed. It would feed the bugs and house the bats, he figured. It would never earn him or his heirs a penny in lumber, but it could stay.
“I’m looking for balance,” he said. Besides working toward an eventual series of paydays from selective logging, he wants a place to walk, to snowshoe, and to enjoy nature. “I want the diversity. I do want to come up and see birds.”
Bruce Cushing trims limbs from a beech he downed with guidance from bird biologists and foresters. He’s working to increase timber yields while also creating young-forest habitat for birds. Photo by Mike Lynch
On this outing, he and an owl startled each other, the owl flushing from a hemlock limb overhead. Other times he has seen woodcocks dancing in the air, and many birds he can’t identify.
An hour from his home on the Hudson River, this property keeps him busy a few days a week, clearing brush and stacking wood, carrying out buckets of maple sap in season. “It’s going to keep me living until I’m 100,” the 62-year-old said. Then maybe his daughter can enjoy the rewards of the timber he’s growing—but not all at once, as he recalls his father’s anger at loggers who convinced him to sell trees from their old New Hampshire homestead and then cleared it indiscrimately.
He’s just the kind of landowner Audubon New York has in mind for its “Woods, Wildlife and Warblers” program.
Started in Vermont in partnership with the Tree Farm forestry certification program and other agencies, the warbler effort aims to knock some of the Northeast’s dense forests back into an earlier succession that favors certain birds and the insects they eat. Absent human influence, this wouldn’t be necessary. Storms, fires, insects or other disturbances would topple older trees here and there, letting sunlight to the ground and opening habitat for the species that live there.
Today, though, much of the region’s forests grow on former croplands that were fallowed around the same time—in the span of a lengthy human lifetime, since the Great Depression. These mixed hardwoods can live on for hundreds of years.
Audubon New York Forest Program Manager Suzanne Treyger stands among goldenrod plants growing in a patch of young forest near Lake Champlain’s south end — shrubby habitat that’s ideal for ground-nesting birds such as the golden-winged warbler. Photo by Brandon Loomis
“A lot of our bird species don’t have that much time,” said Suzanne Treyger, forest program manager for Audubon New York.
The golden-winged warbler is one of them, living around the edges of the Adirondacks near Lake Champlain and, in a larger but also plummeting Great Lakes population, in the St. Lawrence Valley. But its needs coincide with others that are widespread in the park, such as the indigo bunting or the wood thrush. Some of these species nest in the grassy openings, then move into dense forest after their young fledge. Others do the opposite, nesting in deep forest but then moving into the open to feast on caterpillars or berries. They need a diverse landscape, and a stair-stepping transition zone instead of abrupt forest edges.
Treyger demonstrated the ideal this summer by visiting a warbler haven owned by the Nature Conservancy, east of Champlain’s narrow South Bay and just across the Vermont line. Stepping from her car, she heard an indigo bunting’s song. Then a red-shouldered hawk’s cry. Then a common yellowthroat’s chatter. “This is a really diverse area,” she said.
She marched along the forest’s edge to an opening into what she called an old field—the rare habitat Audubon seeks to emulate. Unlike a working farm field or pasture, though, its 5-acre expanse grew thick with waist-high goldenrod and grasses, interrupted here and there with patches of maples and young ashes, with those surrounded by shrubs and dogwoods. Grasshoppers rattled around in the undergrowth, where golden-winged warblers nest out of sight from flying predators.
Cushing leaves untouched any milkweed plants he finds — even in the middle of his haul road. The plant provides habitat for caterpillars, which birds eat. Photo by Mike Lynch
This kind of habitat is rare in the Adirondack interior, Clarkson University biologist Tom Langen said. Working forests on the park’s private lands can encourage diversity. In much of the park, though, it’s village and hamlet edges or the clearings under power lines that provide it. Elsewhere, forest density pushes some species out. It’s one reason spruce grouse are so restricted here.
That’s not to dismiss the Adirondack Forest Preserve’s logging prohibitions. Species such as goshawks shy away from forest edges, Langen said. For them, the state’s “forever wild” provision on public lands offers rare security. “There’s not a lot of old protected forest in the eastern United States.”
“We don’t want to cut into healthy forests at all,” Treyger said. Broadly speaking, though, there’s a dearth of young growth for warblers and other species who need it.
Encroaching middle-aged forests aren’t the only threats to these birds, by a long shot. They winter in Central and South America, where coffee production eliminates habitat (buying shade-grown coffee can help). Along their migration route they face challenges from climate change and pesticides, the same as most bird species. Cornell University biologist Kenneth V. Rosenberg and collaborators this fall published a study in Science estimating a 29 percent loss of all North American wild birds since 1970. That’s a crash of some 3 billion birds.
The wood thrush is among species that benefit from shrubby forest openings in the interior Adirondacks. Photo by Larry Master
“They’re not making it (back north),” Treyger said. “Or, once they get here, they’re not healthy enough to produce healthy young.”
The American Forest Foundation identified 30 Northeast watersheds with habitat deficiencies, and provided grants toward programs like Woods, Wildlife and Warblers, said Mary Jeanne Packer of New York Tree Farm, which works with landowners to promote resilient forests.
In the Champlain and upper Hudson watersheds there are 1,400 owners with at least 100 acres, but only 800 have New York mailing addresses, Packer said. Their middle-aged woodlots sit mostly untouched, while many local owners merely trim occasionally. Only 14 percent work with professional foresters (something Audubon and Tree Farm aim to remedy).
The top reason that surveyed owners give for keeping woodlots is to help and enjoy the wildlife, she said.
“We think we’re doing something by clearing out underbrush, or leaving all these tall trees,” Packer told landowners who attended an Audubon forestry workshop this summer at the Wild Center in Tupper Lake. “Come to find out, (birds) like differences.”
The golden-winged warbler is among birds Audubon New York hopes to conserve by promoting young forests. Its Appalachian population extends as far north as the Champlain Valley, but has declined by two-thirds in 50 years. Photo Courtesy of Audubon New York
Important as it is to promote young-forest habitat, bird conservation is no call for clear-cutting the Adirondacks.
“You want clumps,” Audubon conservation biologist Andy Hinickle told the landowners. “They evolved with this disturbance.”
Still, he showed a slide of a field trimmed of most of its trees, and said it would provide for many bird species in the same way that beaver meadow do. Outside, Audubon staffers led a bird-banding demonstration, netting purple finches—a conservation priority in New York, and one that favors Tupper Lake’s mix of hardwoods and pines.
To help create diversity on private lands, Woods, Wildlife and Warblers has enlisted industry.
Lyme Adirondack Forest Co. is managing its 3,000-acre Kunjamuk Young Forest Demonstration Project near Speculator for wildlife diversity. Audubon invites landowners on tours there to see how a mix of early- and late-succession tree stands can provide for both wildlife and timber revenues. Treyger considers it some of the best bird habitat she has seen, hosting several species of warblers plus woodcock, ruffed grouse and wood thrush.
International Paper’s mill in Ticonderoga has signed on to buy trees from small landowners as a Woods, Wildlife and Warblers partner. Foresters with the company believe what’s good for the birds is also good for the forests that will provide products in the future, fiber said Wayne Majuri, the mill’s fiber supply manager. Staggering age classes and tree species can help the region’s forests adapt to environmental shocks.
“In this period of climate change we say that it’s very important to have healthy forests,” he said.
International Paper has bought wood from a couple of small forest tract owners in Vermont, and is discussing purchases from a couple more in New York. This represents an initial step toward what the company expects could become a larger program in which it helps connect owners to professional foresters who can manage for both timber and habitat, Majuri said.
The mill employs about 600 and buys wood in a zone from Albany north to the Canadian border and west to Watertown—a zone dominated by the Adirondacks. To participate, owners would need at least 25 acres, and preferably 50, Majuri said. Deploying logging and trucking equipment is expensive, and requires a certain payoff.
Families with even smaller woodlots can make a difference, though, Packer told Cushing and several other landowners who attended the Tupper Lake workshop. “Your 20 acres can make a big difference” by setting an example, she said.
Audubon will visit willing landowners and assess forest conditions in relation to a 2,500-acre block around them. If at least 5 percent of that block is young forest, Treyger said, a forester might recommend simply removing some individual trees or slowing the proliferation of afflicted beeches. If there’s less young forest, they might suggest creating a patchy clearing of up to 5 acres. This is true even in the heart of the Adirondacks, where golden-winged warblers don’t live, because it can benefit other species, such as wood thrushes, that use openings after fledging in mature stands.
Most people who participate own 50 acres or more. For backyard birders who want to improve an acre or two, Treyger suggests consulting Audubon’s Bird-Friendly Communities program.
Cushing is doing everything he can to make his 100 acres count.
He carries 5-gallon buckets of rocks to where they can prevent erosion on his work path, so he can keep accessing and cutting new areas. “You want to talk about getting your arms stretched out!”
He plants chestnuts in places where he finds nut trees growing naturally, and is putting tubes on young maples to protect them from deer. “If it grows into something, great. If not, it’s a day’s work.”
He douses his pants in “tick juice,” hitches them up with suspenders and wades into patches of brush with a weed mower after ground-nesting birds leave for the season. “I still like to (hike), but here I can feel it. I get my hands into it.”
And he is enlisting a cadre of experts to help him balance a future harvest of oak, maple and white pine with what the birds need today. Prominent among them is Treyger, who stopped by to advise him this summer.
They plucked and savored some raspberries from one of his shrubby draws, and admired some standing dead trees that should entice birds and bats alike. Then they walked up the skid path, skirting a broad-leafed milkweed plant that Cushing had left for the butterflies.
“There’s a big beech,” he said, pointing to a tall but ailing tree that had sent up dozens of smaller shoots to replace itself. “Should I leave it, or take it out?”
“I would say take it out,” Treyger answered.
“Good. I’m looking for something to do.”
“If you cut that and paint the stump (with herbicide) it should take a lot of that growth out,” she added. “It sounds like such a diabolical plan.”
Diabolical for that tree. Heavenly for the birds.
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