GRAYLING, MI – Saving the Kirtland’s warbler from extinction is touted among the greatest conservation achievements in Michigan history.
The migratory songbird was one of the first added to the federal list of endangered species. That prompted conservationists to create thousands of acres of jack pine habitat specifically for the warbler and even take the fight to parasitic cowbirds known to take over warbler nests.
As a result, the bird’s numbers soared, and the species was delisted in 2019. Field scientists counted an estimated 2,245 pairs in 2021, and another population survey is planned this year.
But researchers at the Michigan Natural Features Inventory (MNFI) say the way the warbler was rescued harmed other rare and native species. Their report says that unintended consequence was caused by an industrial forestry approach rather than using fire, which is the way the Michigan landscape naturally evolved.
This scientific revelation may now prompt a new chapter in how Michigan tells its signature conservation story. After decades of a tree-planting technique proven to benefit the Kirtland’s warbler, advocates want the mechanized method curbed and the return of a more natural approach.
Weaving an ecological conundrum
Conservationists and wildlife regulators swooped in to rescue the Kirtland’s warbler after only 167 breeding pairs were found in 1974 and again in 1987 as the bird teetered on the brink of extinction.
State and federal scientists worked with nonprofit groups to create a rotating forest of tens of thousands of acres specifically to save the migratory bird with its distinctive song, bright-yellow breast, and sleek gray wing feathers. Michigan built a jack-pine lifeline for the critically endangered songbird when the species isn’t wintering in the Bahamas.
The bird nests on the ground beneath the branches of jack pines, a scraggly tree species evolved to require fire to open its cones and regenerate. Foresters use soil-trenching equipment to plant jack pine in a distinctive pattern – high density trees with periodic openings – to mimic the effects of fire on the land. This is called the “weave,” and the birds love it.
“Now that they’ve got the plantations figured out, those are warbler factories,” said Dan Kashian, forest ecologist and longtime professor at Wayne State University in Detroit.
The trouble came in recent years when land surveys by MNFI scientists showed although the Kirtland’s warbler flourished within the man-made jack pine plantations, the weave proved terrible for just about everything else.
Wildflowers like the northern blazing star, wood lily, and bird foot violet dramatically declined from the landscape. Insects like the dusted skipper butterfly, secretive locust grasshopper and blazing star borer moth were driven away.
Those missing species are native to Michigan’s disappearing pine barrens, ecologically natural savannah-style habitats created by wildfire and traditional Indigenous burning. The MNFI report says large areas of those natural pine barrens were converted to jack pine weave and farm fields and today only 5,785 acres remain.
“During the conversion process, overall plant biodiversity appears to decline at the site level. While expansion of the jack pine plantations has supported recovery of the Kirtland’s warbler, broad suites of other species associated with pine barrens are now in decline,” according to the MNFI report published in December.
And it gets worse.
Jesse Lincoln is an MFNI plant ecologist and the lead author on the report. In January he told a crowd during a stewardship conference in East Lansing that even the flames of wildfire failed to restore the lost biodiversity in areas of jack pine weave that used to be pine barrens.
He said the natural seed bank in the soil was gone and there’s no getting it back. The weave effectively made a monoculture, like row crops.
MNFI scientists now recommend forestry and wildlife managers make a complete about-face and stop turning any more natural areas into jack pine weave. The Kirtland’s warbler can easily survive with the plantation areas that already exist, Lincoln argued.
“A lot has been lost to the weave and continues to be lost to the weave,” Lincoln said. “Much has been sacrificed at the altar of the warbler.”
“We have to stop converting natural areas to plantation. I think the weave is great. I just don’t think we should ever, anymore, forever, do any more weave in unwoven spots,” he said.
Kashian said he saw this ecological conundrum coming years ago.
Back in 2009, the Wayne State researcher suggested Kirtland’s warbler habitat expansion should be curtailed. The bird’s population was at 1,800 pairs by that point, which he argued was well beyond the official recovery goal of 1,000 breeding pairs.
The longtime ecologist criticized how rare plants were “plowed up” for the jack pine weave and raised concerns there may be negative effects on biodiversity. He wanted to talk about dialing back the Kirtland’s warbler crusade, and that was 16 years ago.
But he said that didn’t happen. “They weren’t slowing down, almost because of the inertia of the program. They didn’t know how to slow down. They didn’t have an exit strategy. They didn’t know what to do, so they just kept doing what they were doing,” Kashian said.
Regulators of the bird of fire
Michiganders love the iconic Kirtland’s warbler.
There’s the vehicle license plate with the warbler on it that raises money for wildlife conservation. Vibrant spring tourism brings flocks of birdwatchers to the woods around Grayling and Mio, the heart of warbler country. In true Michigan fashion, there’s even an annual festival in Roscommon.
A male Kirtland’s warbler is shown singing while perched. An estimated 2,245 breeding pairs of the migratory songbird were counted by field scientists in 2021. The species was removed from the federal list of endangered species in 2019.Michigan DNR
The Kirtland’s warbler is a cultural touchstone in Michigan. Perhaps that’s why there’s resistance to the notion of overhauling the immensely successful way the beloved birds are stewarded by state and federal officials.
Wildlife biologist Erin Victory leads the Kirtland’s warbler program for the state Department of Natural Resources. She said the collective conservation effort is a complicated calculation and other methods will take time to figure out.
“Plantation management has been the paradigm up until now, and certainly probably for the foreseeable future, although we are looking to explore different management techniques, including fire,” Victory said while speaking on a panel of experts at a controlled burning workshop in Grayling in February.
Today the Kirtland’s warbler depends on humans to provide it with jack pine habitat because of widespread modern fire suppression; Michigan and federal agencies are bound by agreements made when the bird was delisted. The warbler team must maintain a certain number of the birds based on jack pine densities, Victory said.
The U.S. Fish and Wildlife Service (FWS) is the agency that oversees the continued Kirtland’s warbler conservation partnerships among nonprofits, state and federal agencies. The team of public and private researchers strives to ensure the long-term sustainability of the species.
A spokesperson with FWS said the agency is working with partners to assess how to return fire safely and responsibly to the landscape.
“Though prescribed fire would likely promote more biodiversity than the opposing weave method, community safety is our highest priority. The Kirtland’s warbler conservation community is also developing improved mechanical treatment methods that support ecological health and a robust Kirtland’s warbler population,” the spokesperson said in an email.
The Kirtland's warbler teetered on the brink of extinction until conservationists built a rotating jack pine plantation system to provide enough habitat for the migratory songbird to be removed from the federal list of endangered species in 2019.MLive files
Steve Roels of national nonprofit American Bird Conservancy is the coordinator of the official Kirtland’s warbler conservation team. He believes positive changes are coming thanks to ongoing research and a culture of mutual respect among those working in the jack pine ecosystem, he said.
The Kirtland’s warbler will hopefully become a true “umbrella species,” where land managers ensure habitat for the bird as well as other species of conservation concern, Roels said.
Sea change in jack pine forestry
Some of the biggest cheerleaders for the Kirtland’s warbler are ready to chart a new course.
After all, conservationists don’t exactly want the last chapter in the tale of Michigan saving the Kirtland’s warbler from extinction to be the decimation of other native pine barrens species.
“We hit upon a special sauce to protect Kirtland’s warblers – the weave pattern – but we came to realize and it’s clear to everyone that we need to reassess what we’re doing and how we’re doing it in order to protect the entire landscape,” said Bill Rapai, executive director of nonprofit Kirtland’s Warbler Alliance.
The warbler team is set to meet in July and this biodiversity loss problem can be expected on the agenda. After 50 years of this “artificial management” of the jack pine forest, the question is what comes next, Rapai said.
He suggests jack pine planting techniques that are less disruptive to the soil. And he also likes the idea of rotating existing jack pine weave plantations going forward rather than converting any more natural areas.
Jack pine weave plantations feature meandering rows of planted jack pine that create oval-shaped openings between dense rows of pine, seen on the left side of this photo. According to the Michigan Natural Features Inventory, the process of converting natural cover to the jack pine weave plantation is eliminating large areas of recoverable pine barrens, like those seen on the right side of the photo.Jesse Lincoln/MNFI
“I do think the answer to pretty much everything is finding the ways to let the ecosystem behave as naturally as possible, and that involves fire. We have to figure out a way to get fire back on the landscape,” Rapai said.
And he’s not the only one who thinks change is on the horizon for warbler habitat work.
A new biodiversity-focused effort called the Northern Pine Plains Partnership (NPPP) is expected to have an influence, said Chris Engle, from Gaylord-based Huron Pines conservation nonprofit. The partnership includes state and federal agencies and other natural resources experts.
Engle said now that many of those stands of jack pine weave plantation are aging out of usefulness for the Kirtland’s warbler, the NPPP is collaborating on holistic efforts to restore the entire ecosystem for the benefit of all native species, including the Kirtland’s warbler.
Methods are expected to include native plantings, native seed spreading, timber management, prescribed fire, and more.
Rapai said that like a Great Lakes freighter it will take time to steer away from a single-species focus to landscape-scale management, but a new course is being plotted.
“We are thinking beyond just the Kirtland’s warbler,” Rapai said. “We’re thinking about the Kirtland’s warbler, yes, but we’re thinking about everything else, too.”
An Americorps volunteer plants a jack pine tree by hand to help create habitat for the Kirtland's warbler songbird.Kirtland's Warbler Alliance
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