TOWNSHIP 4, RANGE 14 — After flying from Central America this spring, a small, yellowish songbird called a mourning warbler homed in on a patch of forest northeast of Moosehead Lake and determined it was the right place to find a mate and raise a family.

This patch is no wildlife refuge. Five or so years ago, loggers harvested most of the trees, leaving a tangle of branches and trunks. Now waist-high maples and alders, raspberry bushes and ferns are emerging amid the slash. It’s the perfect habitat for this warbler, a secretive bird that likes to nest near the ground, eat insects and spiders and is more frequently heard than seen.

Nearly 30 years ago, a team of bird researchers came to this land to conduct the first large-scale study of the impact of commercial forestry on bird populations in the United States. At the time, a big paper company was in the process of clearcutting 15,000 acres. That’s an area the size of Manhattan.

The Ragmuff Clearcut, named for a stream and road bearing the name, was unsightly and disturbing to many humans. But migrating songbirds such as the mourning warbler, a species that has been declining in Maine, according to breeding bird surveys, didn’t seem to mind.

A systematic survey of bird populations across 1 million acres of working forest led researchers to what was then a surprising conclusion: Cutting down trees isn’t necessarily bad for birds – as long as the harvesting was taking place across a larger landscape where the types of tree and age class were constantly changing over time.

That concept came to be known as a “shifting mosaic.” It highlighted the role of commercial forestry practices in conserving biodiversity, because healthy bird populations are an indicator of a larger, healthy environment for wildlife.

Chestnut-sided warbler Photo courtesy of Maine Audubon/Ariana van den Akker

Different songbirds thrive in different types of forests. The observation that commercial forestry and breeding songbirds could coexist was important for Maine. Roughly 10 million acres – half the state’s land mass – was a contiguous working forest punctuated by sparse development.

That’s still true in 2021. Maine’s North Woods remains the largest uninterrupted tract of forest east of the Mississippi River. And as more land is developed in Maine and elsewhere, the ability of commercial forests to provide a welcoming summer home for songbirds will become even more vital for retaining biodiversity.

An aerial photo from 1993, below, shows dramatic changes in a 15,000-acre tract of commercial woodland northeast of Moosehead Lake. The Ragmuff Clearcut, as it’s known, reflected forestry practices of the 1980s.

Below, the same area in 2021. Today, most of the land is reforested and in the early stages of being thinned by new landowners. Researchers are studying the impact of changing forestry practices on migrating songbirds, in a nationally significant nesting area.

Courtesy of John Hagan

THE CLEARCUT PARADOX

In 2019, a landmark study published in the journal Science concluded that the number of birds in North America had fallen overall by nearly 30 percent since 1970, a decline of nearly 3 billion birds in 50 years.

Today, the National Audubon Society has identified 17.8 million acres of forest in western and northern Maine as the largest “Important Bird Area” in the contiguous United States, as well as a top global priority for conservation.

And while not directly tied to bird habitat, this extensive woodland acts like a giant sponge that helps soak up at least 60 percent of the state’s annual carbon dioxide emissions, a critical buffer against the impacts of climate change. Maine’s Climate Action Plan calls for creating incentives to increase carbon storage through forest management practices, and a task force now is looking at that issue for small to midsize landowners.

Against this backdrop, the key researchers who carried out the 1992 work have come back to Maine.

They’ve begun a three-year, $300,000 study aimed at repeating the survey work they did three decades ago. They call it the “Thirty-Year Bird Study: Changes in forest practices and bird populations in Maine’s commercial forest: 1992-2022.”

The researchers want to see which bird populations have increased or declined, and how those changes compare with regional and national trends. In concert with landowners, they also want to determine whether some of today’s forest management practices could be fine-tuned for the benefit of both birds and timber supply.

“What we’re trying to do is to put this commercial landscape into a national perspective,” said John Hagan, an ornithologist and senior adviser on the project.

A logging crew clears a 13-acre tract of fir and spruce trees in Maine’s North Woods on July 21. The stand is in an area where trees are prone to wind damage, so foresters with Huber Resources Corp. who manage the land decided to cut the trees now. The trees were bound for Moose River Lumber Co. in Jackman to be made into two-by-fours. Staff photo by Gregory Rec

Hagan is the former president of Manomet Inc., a nonprofit conservation and research organization with offices in Brunswick and Plymouth, Massachusetts. He lives in Georgetown and now focuses on climate change issues.

Over a two-day period in July, Hagan led a tour of commercial forestland, harvesting operations and bird survey plots in an area located roughly between the northeast tip of Moosehead Lake and Chesuncook Lake. This is a remote region bisected by logging roads and streams, punctuated by ponds and wetlands. Here, a full spectrum of how timber is managed in Maine’s spruce-fir northern hardwood forest is on display, including clearcuts.

Hagan had to confront the paradox of clearcuts 30 years ago, when a forester first took him into an adjacent logging operation. In a policy paper he wrote in 1996, Hagan called it an “appalling sight” that left him disoriented.

But when his field crew starting surveying the area in 1992, they found the scrubby area full of birds.

He wrote: “Many of the species that used these habitats were species of conservation concern (e.g., chestnut-sided warbler, common yellowthroat, American kestrel, Lincoln’s sparrow, mourning warbler …). Clearcuts were not the biological deserts I had thought. My own data demanded that I confront my preconceptions.”

In July, Hagan was still struck by the contrast when he compared an aerial photo of the Ragmuff Clearcut in 1993 with a drone shot he took this year. Twenty-eight years later, most of the 15,000 once-denuded areas in the clearcut are covered with standing timber. It has become one of the largest tracts of mid-age forest in Maine.

“Clearcuts grow back in Maine,” Hagan said.

Thirty years after leading a landmark study of how forestry in northern Maine impacts migrating birds in North America, John Hagan and researchers are back on the land to examine how changes in land ownership and forestry practices are impacting bird populations. National Audubon has designated Maine’s commercial forests as the largest “Important Bird Area” in the contiguous U.S. Gregory Rec/Staff Photographer

LOSS, CHANGE AND OPPORTUNITY

A mix of factors have altered the condition of Maine’s commercial forests over the past 30 years, and the bird habitats they provide.

For starters, massive clearcuts are a thing of the past. Public outrage over photos such as the Ragmuff operation triggered a hotly contested referendum to ban clearcuts in 1996. The measure was defeated, but it put the industry on notice and led to stricter state regulations, such as the Maine Forest Practices Act, which limits clearcuts to 250 acres.

Large clearcuts have been replaced by partial harvesting operations. That has resulted in more acres being cut each year to feed lumber and paper mills.

Driving the changes in silviculture, the term for tree cultivation practices, is a shift in who owns the Maine Woods.

Maine’s historic, vertically integrated timber companies such as Great Northern Paper and its successor, Bowater Inc., owned the Ragmuff land. Those companies no longer exist. Nor do the paper mills they supplied in Millinocket and East Millinocket.

In their place came a fragmented ownership of timber investment management organizations and individuals with different goals and shorter financial time horizons. They were more likely to cut on a 10-year cycle, for example, so trees didn’t get large enough to support bird species that like to nest in mature forests with closed canopies.

At the same time, the market transition gave conservation interests a once-in-a-generation opportunity to buy and preserve large tracts of what had been working forest.

South of the township, the Appalachian Mountain Club purchased 70,000 acres in 2003 from International Paper Co. for its Maine Woods Initiative. The group is raising money now to buy 27,000 additional acres from an investment fund. Some of this land is being sustainably harvested, but other tracts will grow into ecologically important mature forest.

On the eastern shore of Moosehead Lake, the state was able to buy 4,242 acres in 2002 that comprise Big Spencer Mountain and mature hardwood stands that haven’t been cut in more than a century. Today, the parcel is part of the state’s ecological reserve system.

PARADISE IN THE DARKNESS

These changes are evident today across the landscape northeast of Moosehead Lake, as is the concept of a shifting mosaic of managed forestland. In July, foresters from LandVest, Huber Resources Corp. and Weyerhaeuser Co. offered to explain their management practices on some of the land being surveyed by the bird researchers.

In one section of the old Ragmuff Clearcut, a thicket of balsam fir is taking over. Foresters disparagingly call this a “dog-hair stand.” The trees are so close together that a person can barely squeeze through the branches. It’s nearly dark inside.

But songbirds that nest in this habitat, such as golden-crown kinglets and bay-breasted warblers, like the close quarters. They have been observed by the project’s field crew – Jonah Levy, a Tufts University graduate student, and Kelsi Anderson, a biological researcher from Colorado.

Standing in the dense woods last month, the researchers discussed how this stand provides the meals nesting birds count on, such as spider eggs and moth cocoons. Levy found an inchworm on the forest floor and examined it.

“There must be the right kind of food for them here,” he said. “The nesting season is so short, they need to find the right food to raise their young.”

Levy and Anderson have come to know this land well. While birds were calling and looking for mates in May and June, the duo conducted predawn bird surveys on a total of 120 sites.

Field researcher Jonah Levy makes his way through a thicket of balsam fir, disparagingly referred to as a “dog-hair stand” by foresters, on July 20 in an area of Maine’s North Woods that was part of a 45,000-acre clearcut in the late 1980s known as the Ragmuff Clearcut. While some bird species prefer the thick habitat, the density of the small trees makes it challenging for foresters to thin the trees to allow preferred species to mature. Gregory Rec/Staff Photographer

Expert birders don’t need to see a bird to identify it. They do most of their work by ear, listening and recording data inside a set radius.

The results of these so-called point counts can be compared with data from 1992. Next year, a bigger field crew will survey three times as many sites in the Moosehead Lake area, to coincide with the work done three decades earlier.

With the point counts done, the field crew was returning in July to the sites to conduct vegetation surveys, documenting the types of tree on the land, their age classes and canopy characteristics. Levy and Anderson used a tape measure to define the plot boundaries. They sighted through a hypsometer, a forestry instrument that calculates height, to determine how tall the trees were. This information is transferred to coded maps.

Although some birds may prefer nesting in a dog-hair stand, it’s a challenging place for foresters, said Jim O’Malley, northern Maine regional forester for LandVest.

Ornithologist John Hagan walks out of a stand of softwood trees, dominated by tall black spruce, along the Golden Road in Maine’s North Woods on July 20. This type of stand is the preferred habitat for the blackburnian warblers because they prefer to nest in high tree canopies. Staff photo by Gregory Rec

LandVest is managing this parcel for a company owned by Peter Buck, co-founder of the fast-food chain Subway. Buck, a South Portland native and Bowdoin College graduate, owns more than 1.2 million acres in Maine and is the country’s seventh-largest private landowner, according to The Land Report.

O’Malley has been attempting some thinning in the area, but the thick stands make it hard. This stand also is vulnerable to damaging insects, notably the spruce budworm, so he’s considering options.

“Do we continue to thin, or do we cut it hard and reset the clock?” O’Malley said.

HIGHER PERCHES FOR WARBLERS

The dog-hair stand is very different from the one O’Malley went to next, a few miles away off the Golden Road. This is a mature softwood stand, dominated by tall black spruce. Dappled sunlight penetrates the understory, permitting small balsam fir and maple saplings to spring up.

Blackburnian warbler Photo courtesy Maine Audubon/Ariana van den Akker

Blackburnian warblers, known for their flaming orange throats and their long journeys from South America, like this habitat. They spend their time here high in the canopy.

O’Malley brought along an increment borer, a forestry tool used to extract wood tissue from the core of a tree. After screwing in the shaft, he pulled it out and counted the rings. This tree is 85 years old.

“This is prime saw log and stud wood now,” he said.

On nearby land managed by Huber and owned by Buck’s company, a logging crew was clearcutting 13 acres of 40-year-old spruce and fir. The stand is in an area prone to wind damage, so foresters decided to cut it now.

The harvest is a three-person operation. It started with a feller buncher, a motorized vehicle with a large arm and rotary saw that cut trees and stacked them as it moved through the stand. Behind the feller buncher, a processor instantly stripped the branches. Then a logger driving a forwarder sorted the pile with a grapple and carried the timber to a roadside pile. The logs will end up at Moose River Lumber Co. in Jackman and become two-by-fours.

Black-and-white warbler Photo courtesy of Maine Audubon/Ariana van den Akker

This small clearcut is adjacent to mid-age forest. Warblers and other birds that nest nearby may fatten up prior to fall migration on the raspberries and blueberries that will emerge.

Huber manages 650,000 acres in Maine. Most of its clients want their land harvested in a sustainable manner, according to Trevor London, Huber’s director of operations. The health of birds, which eat vast quantities of insects including those that damage some trees, are part of the management equation.

“It’s important for our clients to operate with the best research available,” London said.

White-throated warbler Photo courtesy of Maine Audubon/Pam Wells

The tour soon came onto a logging road north of Kokadjo, next to land that looks like a Christmas tree farm. It’s a spruce and fir stand managed by Weyerhaeuser. The company owns 850,000 acres in Maine, half of it around Moosehead Lake.

Sixteen years ago, Plum Creek Timber Co. announced plans to create house lots and a resort on 17,000 acres around the lake. Weyerhaeuser, which acquired Plum Creek in 2015, has since abandoned those plans.

In a few years, the company expects to conduct what’s called pre-commercial thinning here. This method removes small growth to space out the stand, so the remaining trees can get big enough to become lumber. That will likely happen in 25 years or so.

Foresters here also had set aside some big trees and wooded patches that can serve as perches for birds. During the visit, Levy heard the calls of a song sparrow and Lincoln’s sparrow, which forage for seeds and insects on the ground. Then the group spotted a sharp-shinned hawk gliding overhead. Sparrows, beware: This small raptor is known to swoop down and catch songbirds in midair.

Ornithologist John Hagan, left, and field researcher Kelsi Anderson compare maps on their phone and tablet before entering a forested area for a vegetation survey on July 21 with Jonah Levy, right. Thirty years after a landmark study of how forestry practices in northern Maine impact migrating birds in North America, researchers are back on the land to examine changes in land ownership, forestry practices and bird populations.  Gregory Rec/Staff Photographer

CRUNCHING DATA TO PROTECT BIRDS

As this year’s field work winds down, Hagan and his team are taking stock of what they’ve learned and gearing up for a major survey effort in 2022. They were able to raise $53,000 from sources including the Cooperative Forestry Research Unit at the University of Maine. They’re currently soliciting funding from national foundations and conservation interests for next year.

The team has developed a matrix from this year’s surveys that records birds per acre and per species, in a variety of forest types. The forest habitats range from clearcuts to mixed hardwood stands and mature softwood stands. The status of each of roughly 60 species of bird is noted for each forest type.

“I’m pleased that the suite of birds is still here,” Hagan said. “They are still using this landscape, and they are as dense as they were 29 years ago.”

But Hagan is concerned about the impact that fewer mature hardwood stands may have on the birds that depend on them, the results of partial cutting and a recent industry preference for more hardwood fiber.

The next step is to compare the data with what’s happening nationally. That will help show whether species populations that are declining in North America are also trending downward in Maine’s commercial forests, and whether different silvicultural practices can help.

The good news, Hagan said, is that Maine’s working forest has largely escaped development pressures after 30 years. It remains a globally significant nesting place for migrating songbirds. The question now is how to balance today’s forestry practices with the needs of birds that have been migrating here for thousands of years, and the new urgency to store more carbon related to climate change.

“Just letting the forest grow,” Hagan said, “is probably not a solution.”


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