NATURAL RESOURCES RESEARCH INSTITUTE

University of Minnesota trademarks fastest-growing poplar tree

John Myers — Fri, 28 Jul 2023 16:00:00 GMT

DULUTH — It’s been said that the true meaning of life is planting a tree "under whose shade you do not expect to sit," a hint, of course, that you’ll likely be dead before the tree gets that tall.

But researchers at the University of Minnesota now say you don’t have to wait that long after all.

The university has trademarked a new, rapid-growth tree that not only will shade your lawn and put up a natural fence between you and your neighbor faster than ever before, but a tree that could be a key to cleaning up polluted hot spots, reducing climate change and developing plastics and biofuels from crops other than corn and soybeans.

It’s called InnovaTree and it was unveiled Friday at Hauser’s Superior View Farm just outside Bayfield, the first place the tree is available for the public to buy.

University officials are hoping InnovaTree will become the Honeycrisp of shade trees. Much as university horticulture experts have developed some of the nation’s most successful apple varieties over the last century, researchers at the Natural Resources Research Institute arm of the University of Minnesota Duluth has spent nearly 30 years perfecting the fastest-growing, most disease-resistant poplar in the world.

How fast? Up to 8 feet in a single Northland growing season, some 64% faster than other hybrid poplars and four times faster than many common landscaping trees. That’s taller than a two-story house in just a few years. It will grow to more than 70 feet tall as a mature tree that can live for an estimated 75 years or more.

“The oldest InnovaTrees now are just 14 years. But its mother is a Minnesota native cottonwood, and those can easily grow for more than 100 years, so we’re expecting a really long-lived tree,” said Jeff Jackson, University of Minnesota Extension outreach educator.

Many uses

Need some quick shade to cool down an urban hot spot amid record-setting heat waves? Rapid-relief erosion control for farm shelter-belts and along streams? Check and check. InnovaTree also is being tested by U.S Forest Service and NRRI scientists for its ability to soak up toxins from polluted hot spots, called phytoremediation, including its ability to absorb sulfate, a byproduct of some mining operations.

Because InnovaTree grows so fast, research shows it can pull toxins out of the ground at a rapid rate. Polycyclic aromatic hydrocarbons, volatile organic compounds and even PCBs and heavy metals can be absorbed and either stored or broken down by the tree’s photosynthesis. And because it absorbs so much water as it grows, InnovaTree is being touted for urban rain gardens where it could slow runoff and help reduce flooding caused by increasing rainstorms.

InnovaTree could even be refined into bioethanol and bio-plastics to replace carbon-spewing fossil fuels. And it could be planted on marginal farmland across the globe to help ease global climate change, absorbing carbon four times faster than a red pine and earning carbon credits for the landowners.

“There’s really nothing else like it anywhere else. Of all the trees they (NRRI staff) worked on over nearly 30 years, this one came out on top,” Jackson said.

InnovaTree is sterile, like a mule, and its seed won’t sprout, so Hauser’s nursery received 25 10-inch cuttings of InnovaTree in 2021 and planted them, with more cuttings from those first trees planted in 2022. This April, Dane Hauser, the fifth-generation owner of the nursery, planted dozens of four-inch InnovaTree cuttings into pots and grew them in a greenhouse. Those cuttings are already 3-5 feet tall and ready for sale.

“For over 20 years, our NRRI team used natural selection and breeding to develop hundreds of poplar varieties in extensively replicated Minnesota and regional field trials,” said Bernard McMahon, NRRI’s now-retired hybrid poplar program tree breeder.

McMahon and other researchers and University officials were expected to gather at Hauser's on Friday to celebrate the results of their efforts. For each InnovaTree sold, the University of Minnesota will get a royalty, with the money planted back into research.

Changing markets

Jackson was called-in to help market the tree that after its originally intended use cooled.

Pushed by calculations in the 1990s that Minnesota's natural forests might run short of wood if demand from board plants and paper mills continued to expand, NRRI scientists went to work on hybrid poplars that could be grown on marginal farmland and replace fiber from forests.

But as the number of mills in Minnesota shrunk due to global competition, the demand on the state’s forests diminished, too. Attention then turned to growing hybrid poplars for biomass fuel to replace coal and natural gas. But that market, at least in the U.S., also cooled as coal prices plummeted and debate raged over whether burning biomass was truly carbon-neutral or not.

While the focus has shifted to the consumer market for InnovaTree, there are still potentially large-scale applications for carbon capture and fiber, Jackson noted. InnovaTree is being tested in Europe as feedstock for plants that produce oriented strand board, called OSB, because native forest trees in Europe are in high demand, short supply and very expensive. And foresters in eastern Europe are eyeing InnovaTree to help reforest war-torn Ukraine where countless urban and rural trees have been obliterated by bombs and shells.

Until then, though, it will be consumer purchases for landscaping trees that U of M officials hope will make InnovaTree famous.

“There are currently millions of hybrid poplars being sold in the U.S. for landscaping every year, and there’s no reason this tree can’t capture a big part of that market considering how much better it is,” Jackson noted. “This is not a tree that’s intended for natural forests. … But for landscaping and for phytoremediation and fiber, planted in cities and on marginal lands, we think it can have a really big impact.”

About Innovatree A cross between native eastern cottonwood and European black poplar, naturally cross-bred over 25 years until the star of the family emerged. Resulted from NRRI research, starting in 1996, on 1,672 hybrid poplar varieties from 115 families in 27 field tests at nine sites in Minnesota and sites in several other states. Is not a genetically modified organism but grows from the same, traditional horticulture practices used for apple and other fruit trees. The NRRI established over 45 field sites throughout the Midwest and Northeastern U.S. and has never had an escaped seedling survive outside the planting area. Doesn’t sucker and its seeds are infertile, so it won’t become an invasive species problem by spreading into native forests. It’s cottonless, so no fluffy stuff in the springtime. Hardiness across zones 3-6 — everywhere from North Dakota, Minnesota and Wisconsin south to Missouri, Kentucky and Kansas. Grows best in full sun in well-drained loam, sandy loam, clay loam and light clay soils with annual rainfall above 20 inches. Captures an impressive 6.8-8.5 metric tons of carbon dioxide per acre per year.

To buy an InnovaTree

A 2-33-foot potted InnovaTree is $20. Visit Hauser’s Superior View Farm, 86565 County Highway J, Bayfield; call 715-779-5404; or visit superiorviewfarm.com. Shipping is available. It’s expected to be available at several other nurseries in the Midwest next spring.

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Northern Minnesota experiment attracted some fishers — and other critters, too

John Myers — Fri, 21 Oct 2022 12:00:00 GMT

DULUTH — For the past three years scientists at University of Minnesota Duluth’s Natural Resources Research Institute have been building houses for Minnesota’s largest member of the weasel family, then attaching them to trees across Northland forests.

NRRI researchers and their partners erected more than 100 den boxes for fishers in an experiment to see if they would be used by the critters, especially to raise their kits.

The answer is an unequivocal yes. And no.

“Fishers used 41% of the boxes we put up,” said Michael Joyce, the NRRI wildlife ecologist who heads the project. “But not for raising their kits.”

The fisher den box project was intended to help find out why Minnesota’s fisher population crashed in recent decades, from an estimated 17,000 to just 7,000. Wildlife managers believe a lack of big, old trees with nesting-size cavities may be a factor. The human-made boxes, some speculated, might help make up for the lack of old trees.

The average age of trees used by fishers to build their nests here is over 100 years and they are bigger than 20 inches in diameter, with aspen their favorite old, rotting tree to nest in. But there are simply very few trees left in the woods that are old and big, fewer than 2%, according to forest surveys.

But if female fishers were desperate for nesting places then they should have used some of the boxes.

“It would seem that if the lack of natural nesting cavities was a major limiting factor for the fisher population, then the boxes probably would have been used more for that,” Joyce said.

“We had fishers in about the same percentage of boxes as an earlier study in British Columbia. But they had 15% of their boxes used for raising kits. And we really didn’t have any,” Joyce added. “Females used the boxes to cache their food … and as a place to hide from males during the mating season. They used them to hold out and choose what males they wanted to mate with. Some of them brought kits into the boxes, but not until summer, and then just to rest for a while.”

John Erb, wildlife research biologist for the Minnesota Department of Natural Resources who specializes in fur bearing species like fishers and martens, said it’s too soon to say that nesting sites aren’t an issue limiting the fisher population.

“All we really know is that they didn’t use the boxes” to nest in, Erb said. “Maybe they just didn’t like the boxes? Maybe they were in the wrong places?”

Another explanation for the lack of nesting could be that there were simply few if any fishers near many of the boxes that had been placed at sites based on fairly old data of where fishers might be living in northern Minnesota. After all, 59% of the boxes never saw a fisher at all.

3.3 million photos

The NRRI fisher den project used high-tech thermometers in the dens, sticky strips to grab hair for DNA and more than 100 motion-activated trail cameras to see what was visiting the boxes and when.

The project discovered that fishers provide a unique temperature fingerprint whenever they entered the boxes, meaning that there’s now an easier way to determine if fishers have been around other than setting up cameras at each site and constantly returning to check their memory cards and change batteries.

“We have to go back three or four times a year to replace batteries and cards in the cameras. But we could go in once a year for the (thermometers) and get really good data to know if fishers had been in that box,” Joyce noted.

But all those cameras did take some really interesting photos, more than 3.3 million images in all, of which project organizers have viewed nearly 30%.

So what was on all those images, other than a few fishers? Many tree branches waving in the wind, but also an amazing potpourri of forest critters — including martens (fishers' smaller cousin) red squirrels (the primary food for fishers) flying squirrels (both northern and southern varieties) gray squirrels, short-tailed weasels, white-footed mice, eastern chipmunks and bats.

Other critters that came up to the boxes to inspect them include porcupines, black bears, raccoons, moose and bobcats. The cameras also captured wolves, deer, badgers, gray foxes and snowshoe hares in the vicinity of den boxes and 36 species of birds on or near the boxes.

Few of the birds went inside, however, except owls and hawks.

“We saw a lot of saw-whet owls keying in on the rodents at the boxes,” Joyce noted.

Fishers, bobcats get GPS collars

Predators are playing a role in the fisher decline, researchers say, and bobcats are the largest predator of fishers. Because bobcats tend to like young aspen forests for their hunting, the more aspen that's cut, the more bobcats prevail. Bobcat numbers exploded from about 2,000 in the 1980s and ’90s to more than 7,500 by 2010. There was a short dip in the bobcat population a decade ago, but their numbers are back up to about 7,000 now, Erb said.

Erb said forest management and the increase in younger forests has likely played a direct role in bobcat increase, which then had additive impact on fishers and martens. He said that fishers and martens appear to have bottomed out a few years ago and that their numbers have stabilized in recent years, “but we’re still way down near the bottom of the modern curve for fishers.”

Erb’s previous research found that so many bobcats are killing so many female fishers that the population of fishers may not be able to sustain itself in northern Minnesota.

Joyce’s crew is capturing both species and fitting bobcats and fishers with GPS collars to track their overlap “to look at how both species are using the shared landscape.”

Female fishers are by far the most vulnerable to bobcats, Erb noted, and Joyce notes the female fishers are most susceptible to predation by bobcats from late winter through early spring, when they are giving birth and caring for young.

Fishers might be picking nest sites too close to where bobcats are common, Erb speculated, meaning where old trees are left standing near logging sites, not just how many, may be a key factor.

“We hope we can get data that shows us where these adult female fishers are, what kind of habitat they are using, when they are so vulnerable to bobcat predation,” Erb said.

Partners in the NRRI den box project include the Leech Lake Band of Minnesota Chippewa, the 1854 Treaty Authority, Vermilion Community College and UPM-Blandin Paper Co. The project was funded through a $190,000 grant from the Minnesota Environment and Natural Resources Trust Fund, the state's profits from lottery sales.

The fisher-bobcat GPS collar project also is on target to be funded from the trust fund through a $400,000 grant with the project continuing through 2024.

About fishers

Fishers are the largest member of the weasel family in Minnesota, resembling a very large mink. They weigh as much as a red fox but have much shorter legs. Fishers are extremely agile and active predators. Excellent tree climbers, they can out-climb martens and red squirrels.

Fishers prey upon red squirrels, snowshoe hares, mice and voles and are the only natural predator of porcupines. Fishers will also eat insects and berries. Despite its name, the fisher does not catch or eat fish.

Identification

The fisher is a medium-sized, long-shaped predator that belongs to the weasel family. Adult fishers are 24-30 inches long, including their long, bushy tail. Female adults weigh 6-8 pounds; males weigh up to 18 pounds. Their fur is a grizzled dark brown, blackish on the rump and tail, with a white or cream-colored bib on their chest.

Roller-coaster population

Fishers have had an up-and-down century or so in Minnesota. They were trapped and logged nearly out of existence by the early 1900s, considered extirpated from Minnesota forests. But by the late 1950s, as forests grew back and aged, fishers started to show up again. By the 1970s, Minnesota was allowing trappers to kill a limited number of fishers each year. Then that harvest got too high, topping 3,000 in 1979, leading the DNR to close the season entirely by 1980.

Fisher numbers built again, peaking in the early 2000s at more than 16,000.

Again, trapping increased, to a high of 3,251 killed in 2006 during a 16-day season with a five-fisher limit. The population dipped again to just 6,000 and by 2018 the DNR had cut the fisher trapping season to just six days, with a two-fisher limit, and only 510 were killed.

Erb said the northern Minnesota population appears to have stabilized at the lower level now, much like Minnesota moose, with an estimated 7,000 fishers across the landscape.

Fishers expanding south and west

While their numbers are flat now after a steep decline in the north, Erb notes fishers continue to push south and west in Minnesota, and have sustained populations in agricultural areas, especially in hardwood forests of southeastern Minnesota. Fishers also are re-colonizing the Red River Valley area of northwestern Minnesota, Erb said.

2022 trapping season

The Minnesota Department of Natural Resources allows a short trapping season on fishers and their smaller cousins, pine marten, this year set for Dec. 17-25. The season limit is two of either combined.

Reproduction

Like most members of the weasel family, female fishers have what is called "delayed implantation." Females get pregnant in spring, just 10 days after they have given birth. For the next several months, the young exist as tiny embryos. Then, two months before being born, the embryos develop into fetuses.

One to five young fishers are born in a hollow tree, log or rock cavity. Within days after giving birth, the female will seek out a new mate. Young fishers stay with their mothers for just a few months. The young leave the female in early fall to find their own home territory.

Habitat and range

Fishers prefer large areas of continuous forest, particularly older timber stands. They are adaptable, but avoid open areas. They prefer the edges of conifer stands when these are adjacent to stands of deciduous trees. Hollow trees are their primary denning sites, but they occasionally den in rock crevices, abandoned beaver lodges in dry ponds and old porcupine dens.

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UMD scientists study phytoplankton, the base of Great Lakes food chain

John Myers — Sat, 09 Jul 2022 13:54:00 GMT

DULUTH — The base of the food chain across the Great Lakes is changing in ways affecting the top of the food chain, the fish we love to catch and eat, and scientists at the Natural Resources Research Institute at the University of Minnesota Duluth are trying to find out why.

The problems are different in each lake, but start with tiny plants called phytoplankton, microscopic marine algae.

In a balanced ecosystem, phytoplankton are the food for small creatures called zooplankton and for small fish, which in turn are eaten by bigger fish. But the Great Lakes systems aren’t all in balance.

The NRRI researchers will track how phytoplankton are changing, identify reasons for the changes and make recommendations on what can be done to protect water quality in the lakes and manage the fish in them.

“It’s more of a food web, really, than a food chain. It’s all interconnected. And the people who are trying to manage fish species out there, and protect water quality, need to know what’s happening at the base of the food web,” said Euan Reavie, the NRRI scientist heading the $3 million study funded by the Environmental Protection Agency as part of the Great Lakes Restoration Initiative.

From invasive species like mussels to warming waters and ongoing pollution, each lake faces multiple stressors. In Lake Michigan, billions of invasive quagga mussels have filtered out virtually all of the phytoplankton in the deep parts of the lake. Reavie says that’s created a virtual dead zone for deepwater fish like cisco, lake trout and whitefish.

“The fish in the deepest parts of Lake Michigan are starving,” he added, even as fish near shore, like salmon, are doing OK.

The latest NRRI effort started this spring and will continue for five summer seasons with a dozen scientists fanning-out across the lakes, on boats like the EPA’s Lake Guardian.

UMD scientists have been studying sediments in the Great Lakes for decades and crews have been looking at deepwater phytoplankton in the lakes since 2007, Reavie said.

The latest effort started this spring and will run across five summers.

“The goal is to provide managers with some information that they can use to help guide their management decisions,” Reavie said.

Scientists also can use core samples of sediment from the lake bottom to see how phytoplankton has changed — the type and number of them — from decades, even centuries ago.

“That's how we know the phytoplankton in Lake Superior are entirely different now than they were 100 years ago and 300 years ago,” Reavie said. “The ones here before are gone.” So far it’s not clear how or why that happened, or the impact it’s having on the food chain above it — species like herring, whitefish and lake trout that also have been around for centuries

In Lake Erie, huge algae blooms, some of them toxic, are growing more often and cover more water in recent years. Researchers know part of the problem is phosphorus-heavy runoff from agricultural fields in the lake’s watershed.

But scientists like Reavie discovered the problem also starts upstream, in Lake Huron, where invasive mussels have filtered out most of the small algae. That’s created a massive surplus of silica in Lake Huron (formerly picked up by the diatom algae) that's now flowing down into Lake Erie’s western basin, Reavie said, and that’s helped fuel the explosion of algae in recent years.

“Sometimes it’s a combination of things happening that can trigger the problem. And it may not be very obvious,” Reavie said. “The agricultural issues (for Lake Erie) get all the headlines. But the silica is also part of the equation.”

In Lake Superior, a few recent algal blooms, in a lake where they had never historically occurred before, have caused concern. So far, Reavie noted the problem has been limited to the South Shore area close to shore, essentially between the Twin Ports and Ashland. Scientists believe the problem is in part caused by runoff after big rainfall storms on shore. The runoff is carrying all sorts of material — animal waste, agricultural runoff and more — that are fertilizing the algae in the big lake.

But it’s also likely the Lake Superior algal blooms are being spurred by warmer water in recent years. Algae needs warmer water to grow. Both the increased frequency of rainfall and the increase in water temperature are the result of climate change already occurring in the region.

“We know Lake Superior is warming faster than any other lake in the world,” Reavie said. “That’s going to allow for more algae blooms. And probably a few other problems.”

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Damming research: Study finds beavers might not be all bad for trout streams

John Myers — Fri, 08 Apr 2022 11:55:00 GMT

DULUTH — For the past century or so of trout stream management in North America there’s been a general consensus that beavers, beaver dams and beaver ponds are bad for trout.

Beaver dams slow stream flows, warm the water and block fish from passing up and downstream, according to the mainstream view on the issue. So the general rule of thumb has been to trap the beavers and take out the dams from streams where you want trout to thrive.

But new research by several University of Minnesota Duluth scientists has found that beaver dams may actually help trout in some smaller streams.

The research, conducted on the upper reaches of Knife and French rivers on Minnesota’s North Shore of Lake Superior, found that beaver dams on small streams actually helped cool water downstream as well as store water to provide better flow during dry spells. The study even found that small fish can pass over small dams after heavy rains, so the dams may not be the insurmountable walls to fish after all.

The hydrology of beaver dams and streams “is complicated and sometimes contradictory,’’ said Karen Gran, a geomorphologist at UMD’s Swenson College of Science and Engineering and lead researcher on the project. “We have pretty compelling data that beaver dams were helping keep groundwater levels high and the stream discharge flowing and the temperature cooler’’ and that the practice of removing beaver dams on the upper Knife River “designed to help trout was actually detrimental to them.”

The research was funded with a grant from Minnesota Sea Grant.

Gran picked the Knife River after concerns were raised by a local group, Advocates For the Knife River Watershed, that the repeated removal of beaver and dams along the river was excessive. Over the past decade, the Minnesota Department of Natural Resources has overseen removal of 250 beaver and 170 dams on the Knife River, a major element in the ongoing effort to improve trout fishing on the once storied stream.

Gran and Josh Dumke, a fisheries ecologist with UMD’s Natural Resources Research Institute, led teams into the field in the summers of 2018 and 2019 to see what happened on the streams before and after beaver and their dams were removed.

Gran and Dumke are quick to point out that their research was limited in scope and time, and that more research should be conducted to see how far the findings might change over different years or may apply to other streams in other places. But it’s clear not all beaver dams may not be as bad as once thought.

“Removing beaver dams in these small catchments does not guarantee cooler temperatures and may even increase downstream temperatures,’’ Gran noted.

While surface water in beaver ponds is indeed warmer than the moving water, thanks to solar radiation, much of the water that leaves small beaver ponds, especially during low-flow periods such as summer or during droughts, comes out of the dam from below and is in fact cooler. Groundwater that upwells below the dam also is cooler than surface stream water.

The research, which looked at streams with beaver dams intact and streams after they dams were removed, also found that beaver dams and the ponds they create actually helped maintain stream flow during low-flow periods, such as late summer. When the dams were removed, the stream downstream from that point spent more time at very low flows compared to when the dams were in place, indicating beaver ponds may serve an important function in storing water for dry periods.

Over the top

The research also found that smaller beaver dams on smaller streams sections also can be breached by fish. The study, which looked at dams up to 3 feet high, found minnows and small trout were able to move up and downstream of dams when rainstorms swelled the streams and pushed water over the top.

Dumke noted that 78% of the previous scientific writing on beaver dam impact on trout that the UMD researchers could find was in fact speculative and not based on actual field work, apparently leading to some false assumptions.

The DNR has been removing beaver and dams as part of a long-term effort to improve spawning habitat on the Knife River, which is by far the major North Shore reproduction area for rainbow trout. In fact, the Knife River has more miles of fish-swimmable stream than all other North Shore streams combined. (Most Minnesota North Shore streams are blocked to fish close to Lake Superior by barrier falls.) The Knife River also has been the subject of major restoration efforts to curb erosion and reduce sediment, another problem for trout.

While Gran’s team focused on stream flow levels and temperatures below dams, Dumke focused on tracking fish movement in streams with beaver dams, including small trout and minnows. Dumke’s team used electro-shocking devices to stun fish in the upper reaches of the stream, then carefully marked each fish and returned them to their ponds and riffles.

But that part of the project turned out to be more complicated than expected, with most of the 1,200 fish marked by researchers never recaptured. Apparently, the fish moved farther downstream, or upstream, than researchers were looking. It’s also possible some of the small fish were eaten by critters. Only 240 of the 1,200 marked fish were recaptured.

Of those, about 10% made it across low-head dams during periods of high water. (Researchers didn’t have the gear needed to look at bigger dams with deeper ponds.)

The small sample size has Dumke hoping to go back and do more work in more streams. “We documented eight species of fishes — two trout and six non-trout — passing active and inactive low-head beaver dams on Knife and French rivers,’’ Dumke said. “The number of fish passing each dam was significantly correlated to the amount of time water flowed over the tops of dams.”

Beaver numbers increasing

Deserae Hendrickson, regional fisheries manager for the Minnesota Department of Natural Resources, said the recent UMD research revealed some interesting findings. But she said trout stream managers aren’t ready to welcome all beavers in all rivers just yet.

Hendrickson noted that the recent research focused on very small streams, essentially headwater tributaries to the Knife and French rivers, and that previous research clearly found beaver dams can hurt trout on larger streams.

“There’s been a lot of research that (shows) there is often lower oxygen below beaver dams that are being overtopped, at least those on bigger streams that run perennially or all the time, that oxygen levels below the dams can be too low for trout to survive,’’ Hendrickson noted. “And this (UMD) study looked at shorter dams, less than 3 feet, and we have seen a lot of evidence that bigger dams can be a real impediment for steelhead and coaster brook trout that are trying to migrate upstream, cutting off a lot of potential spawning habitat.”

In addition to the Knife River dams removed, the DNR also removed about 80 beaver and 40 dams on the Blackhoof River, the only other stream where the DNR conducts regular beaver control, Hendrickson noted.

Across northern Minnesota, biologists and others are seeing more beaver in more and more places as beaver trapping has declined due to low fur prices. Many former beaver trappers have quit and the DNR now must pay to have beavers removed.

“We’ve seen a pretty big increase in beaver across the landscape on our trout streams over the last 10 or 15 years. Certainly the most I’ve ever seen,’’ Hendrickson said. “It’s costing us more just to keep up.”

Still, Hendrickson said the UMD research has pushed fisheries managers to look at beaver dams differently in headwater streams, the uppermost portions where big fish tend not to go as often but which may be critical for young fish and to supply cool water downstream.

“We’ve certainly looked at what our (beaver) removal practices are because of this. … We have reduced some of our beaver removal on parts of the Knife, the upper areas, in part based on this information,’’ Hendrickson said. “I’d say that we’ve tweaked our beaver management as opposed to making any big changes … We now know there’s no one answer when you have beaver on a trout stream.”

UMD’s Gran says she hopes the research can be one tool for fisheries management and that people who love trout may realize one-size management does not fit all trout streams.

“We’re hoping that the data we’ve collected can lead to a more nuanced approach to trout management on the Knife River,’’ Gran said.

John Myers reports on the outdoors, environment and natural resources for the Duluth News Tribune. He can be reached at jmyers@duluthnews.com.

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Minnesota drivers may hit 20 times the deer reported to state

John Myers — Fri, 01 Apr 2022 13:04:00 GMT

DULUTH — Along a stretch of U.S. Highway 53 just outside of town, University of Minnesota Duluth biologist Ron Moen has investigated 25 dead deer since August, victims of what highway engineers call deer-vehicle collisions.

But if you asked the state Department of Public Safety how many deer are killed along those 8 miles of highway, their records show it averages just 1.1 per year. Only 17 deer-vehicle collisions were reported to police along that stretch from 2006 through 2020.

Moen is finding the same thing in other places, too — far more vehicle-killed deer than are reported to police and on to the state.

“It’s looking like only 10% or less ... are reported,” Moen said.

Officially, Minnesota has about 2,000 deer-vehicle collisions reported to the state each year. But State Farm Insurance, which keeps its own statistics on animal-vehicle collisions, says that number hit 42,874 last year in Minnesota, making it one of the top 10 states in the country for collisions with deer. In Wisconsin, State Farm says drivers hit some 70,000 deer per year.

If State Farm is right, that means state highway officials really have no idea where or when the vast majority of deer-vehicle collisions occur, and that means they can’t work to reduce those collisions until they get better data. That’s why Moen is out searching for deer carcasses, part of a two-year study of deer-vehicle collisions on Minnesota highways.

Moen is the biologist who knows how deer behave. Raphael Stern, an expert on highway safety engineering at the University of Minnesota in Minneapolis, crunches the numbers. The study, funded by a grant from the Minnesota Department of Transportation, hopes to decipher the vast discrepancy between officially reported deer-vehicle collisions and how many actually occur.

“That’s why we’re trying to find out ... how many are there, really, and where do they occur most often. And then is there something we can do to bring that number down?” said Moen, a veteran wildlife researcher at UMD’s Natural Resources Research Institute. “If we could bring that total down even by a few percentage points, that would be millions of dollars saved. And maybe some human lives saved … and some wildlife saved. There’s not a lot of wildlife research that can have such a concrete payback for the investment.”

State law requires an accident to be reported to police if anyone is hurt or if the damage is $1,000 or more. With AAA now saying the average price of repairing a deer collision at $5,000 and rising, it’s not immediately clear why so many are unreported. A dead deer along most rural roads is hardly worth a 911 call, many Northlanders would agree.

Some motorists don’t have insurance that covers deer collisions, others may opt not to report to prevent their premiums from going up. But clearly many motorists are reporting the hits to their insurance companies and not law enforcement.

“I think a lot of times it’s just more of a fender bender, the vehicle is still drivable, and the person just goes on their way and reports it later to their insurance company but not to police,” said Stern, a professor in the University of Minnesota’s Department of Civil, Environmental and Geo-Engineering and principal investigator on the deer-vehicle collision project.

Why did the deer cross the road here?

On a blustery March morning, Moen was investigating yet another dead deer along the four-lane stretch of Highway 53, a big doe in the median near Caribou Lake Road. He takes photos and gets a GPS location for each carcass. He’s still in the early stages of gathering data, but Moen says it’s becoming more clear where many deer-vehicle collisions occur and why.

An average of three or four people die in Minnesota from deer-vehicle collisions each year. It was less than a mile away from this spot where an initial deer-vehicle collision led to a multi-car accident that killed a woman and injured several other people in November 2020.

“This is showing up as one of those hotspots,” said Moen, who is looking at specific segments of various types of roads, from heavily traveled to lightly traveled, two-lane and four, suburban and rural. He's getting carcass reports for those roads form other biologists and his own scouting trips. He'll later plug in the limited data from the state. (Moen has to get to the deer quickly, he noted, because many fresh deer carcasses “walk away” as people claim them for the meat.) Eventually researchers can use data from specific road types to extrapolate out to a more accurate total number of deer-vehicle collisions statewide.

Highway 53 here runs through a convergence of suburban and rural landscapes. Houses are farther apart. There’s more woods, but still plenty of houses with gardens and small hobby farms with great good for deer. And there’s probably not as much hunting going on this close to houses, and maybe fewer predators, than farther out of town.

“This area probably has a pretty high deer density,” Moen said. “Plus you have a four-lane highway with high-speed traffic. It’s a bad combination."

Both for the deer and the drivers.

On a recent 180-mile search from Duluth to Dassel, Minnesota, along state Highway 23 — a heavily traveled highway that runs through prime deer habitat — Moen counted 65 deer carcasses that had accumulated over winter. That's more than one every three miles. State records show only six per year along the entire route.

Stern said the study may also reveal deer-vehicle collisions “coldspots,” places where few if any of the animals are struck. Those areas could be studied to see if factors other than fewer deer or fewer drivers were involved.

By far the highest number of deer-vehicle collisions in Minnesota occur in the Twin Cities, with prime suburban deer habitat criss-crossed with high-speed roadways and lots of drivers.

“I think a higher percentage get reported down there, that’s one reason. But they also have so many more people on the roads, too. … And it’s really good deer habitat,” Moen said.

In 2019 185 people died in deer-vehicle collisions across the U.S. and some 10,000 others were injured, according to federal traffic safety statistics. In the last five years in Minnesota, 18 people died as a result of deer-vehicle collisions, 15 of them were motorcyclists. Deer-vehicle collisions also resulted in 124 serious injuries, of which 109 were motorcyclists, over those five years.

State Farm Insurance, which analyzes animal-vehicle crashes each year, says American drivers hit animals more than 2 million times in the 12 months between July 1, 2020, and June 30, 2021, most of them deer. These are collisions that require repairs, not just birds hitting the windshield or squirrels under a tire. Nationally, wildlife collisions cost $8 billion per year for things like vehicle repair, medical expenses, towing and the removal and disposal of animal carcasses, according to the Federal Highway Administration.

If State Farm’s numbers are right, motorists in Minnesota are killing nearly twice as many deer each year as archery deer hunters.

Highway fixes expensive, but often effective

The Minnesota Department of Transportation stopped putting up new yellow deer-crossing signs decades ago because they turned out to be a waste of money. Motorists simply didn’t change their behavior, namely slowing down where the signs were, and there was no evidence they worked to reduce collisions.

One option used in some areas are motion-activated flashing lights that sense when deer are moving out of a ditch and onto a roadway. But even then, when a system was tested near Camden State Park in southern Minnesota in the early 2000s, it turned out most drivers didn’t slow down. The signs eventually stopped working and were removed and not replaced. It was never determined if they actually reduced deer-vehicle collisions.

“We haven’t given up on them as a potential tool in some areas. But, especially people who might drive the same stretch of road every day, and who saw the lights flashing but maybe didn’t see a deer every time, they just stopped slowing down,” said Chris Smith, natural resources program coordinator for the Minnesota Department of Transportation.

Across the U.S. and Canada billions of dollars are being spent to keep wildlife off highways, namely using overpasses and underpasses, bridges and tunnels designed specifically for animals, often in conjunction with extensive fencing to funnel animals to cross at the right place. They have been used in western Canada’s Banff National Park for nearly 30 years, with surprisingly positive results, with elk, deer and even grizzly bears crossing over four-lane highways without collisions. Results in Wyoming, Utah, Colorado and Alberta show 50 to 90% reductions in vehicle collisions with animals, and trail cameras placed at engineered wildlife crossings often show a surprising variety of species use them often.

In Vermont, underpasses shuttle snakes and salamanders under busy roads. In Florida, it’s panthers crossing under I-75, Alligator Alley. In California, the $87 million Wallis Annenberg Wildlife Crossing being built over the Route 101 freeway on the western side of Los Angeles County is hoped to allow mountain lions to easily cross eight lanes of traffic, substantially expanding their habitat.

Because tunnels are cheaper to build than bridges, they have become the more common solution. In Minnesota, several projects have seen wider bridges and culverts added at stream crossings with hopes animals would stay off the traffic lanes, including along the North Shore and under Highway 53 north of Virginia. The largest and most expensive effort was recently completed under Minnesota Highway 14 in Dodge County near Owatonna. As part of a $108 million project to widen the highway in that spot, engineers added a 200-foot-long, 10-foot-wide and 9-foot-high concrete tunnel — a giant box culvert — that’s hoped to allow wildlife to pass under the road. Fencing has been added to funnel critters that would have crossed the highway to instead go through the culvert.

The wildlife crossing added about $220,000 to the highway project, but may pay off in the long run, Smith said. So far it’s too soon to tell if it’s working.

“That was an area where the DNR came in showing there was some historical deer movement there, seasonally, and we knew we had a lot of deer-vehicle collisions, so we had the information that showed it made sense,” Smith said.

Smith’s hoping the University of Minnesota study comes up with more of those specific areas where projects make sense. In western mountain states, migrating herds of deer, elk and antelope often take the same routes year-after-year, making it more obvious where wildlife crossing projects should be placed. In Minnesota, deer movement is less migratory and more habitat based, usually deer moving between resting/hiding areas and feeding areas.

“It is more random here (in Minnesota) when and why deer might cross a highway. But this study might help show where it’s more likely, where it might make sense to focus our efforts,” Smith said.

Other options include managing vegetation along roadways, Smith noted. Cutting down trees and widening ditches to offer drivers better visibility of approaching deer can help reduce collisions. But Moen also noted that those wider, grassier ditches can also attract more deer to munch on the new food sources available, especially in fall and spring.

Another option is intensive deer management: reducing the deer population in areas where more accidents occur. Duluth police have said there’s evidence that Duluth’s annual city archery hunt has reduced deer density enough to spur fewer collisions on city roads.

“That’s more of a social issue on how many deer people want in an area, how many they are willing to put up with,” Smith said.

New federal money available

The Infrastructure Investment and Jobs Act of 2021, which Congress passed Nov. 5 and President Biden signed into law Nov.15, establishes a wildlife crossing safety program. The law offers $350 million over five years for competitive grants to municipalities, states and tribes for the construction of bridges, tunnels, culverts, fencing and other infrastructure that will allow wildlife safe passage either under or over roads.

Smith said MNDOT will look at adding projects where they might help, not just to protect drivers and their pocketbooks but also to protect wildlife.

Areas where deer cross roads, such as where rivers cross roads, are actually wildlife corridors, or wildlife highways, that are being blocked by human highways. Allowing safe passage between pockets of wildlife habitat helps keep overall populations stronger, Smith noted.

“We are already going through some extensive efforts to keep turtles from being hit on roadways, both endangered and common turtles, and that’s just part of what we’re looking at," Smith said. “We can’t do it everywhere, but let’s take a look at where we can get the most bang for the buck.”

Stern, the University of Minnesota traffic engineer, said he’s interested not just as a highway safety researcher but also as a wildlife enthusiast.

“If we can make roads safer, maybe save some human lives, and also reduce our impact on wildlife, why not try?” Stern said. “Cars are not the best way to manage wildlife populations.”

Top states for deer collisions

A driver’s odds of hitting a deer this year

West Virginia: 1 in 37. Montana: 1 in 39. South Dakota: 1 in 48. Pennsylvania: 1 in 54. Michigan: 1 in 54. Wisconsin: 1 in 56. Mississippi: 1 in 57. Minnesota: 1 in 58. Source: State Farm Insurance
Tips to avoid hitting a deer Drive at safe speeds and always be buckled up. Be especially cautious from 6-9 p.m. when deer are often most active. Use high beam headlights as much as possible at night, especially in deer-active areas. Don’t swerve to avoid a deer. Swerving can cause motorists to lose control and travel off the road, or into oncoming traffic, causing an impact far worse than hitting a deer. Motorcyclists should avoid driving at dusk, dawn and at night. Don’t count on deer whistles or fences to deter deer from crossing roads. Watch for the reflection of deer eyes and for deer silhouettes on the shoulder of the road. If anything looks suspicious, slow down. Watch for multiple deer crossing in the same area. Any Minnesota resident may claim a road-killed animal by contacting a law enforcement officer. An authorization permit will be issued allowing the individual to lawfully possess the deer. If a deer is struck but not killed by a vehicle, keep a distance as deer may recover. If a deer does not move on, or poses a public safety risk, report the incident to a DNR conservation officer or other local law enforcement agency. Source: Minnesota Department of Transportation

John Myers reports on the outdoors, environment and natural resources for the Duluth News Tribune. He can be reached at jmyers@duluthnews.com.

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As climate warms, northern flying squirrels are moving out of the Northland

John Myers — Fri, 18 Jun 2021 22:30:00 GMT

DULUTH -- They are your neighbors that you never see, creatures of the night that spend their days hiding in trees across the Northland and come out only when it’s dark.

Flying squirrels are probably a lot more common than you think, found across most of Minnesota and Wisconsin's forested counties and living their lives pretty much unbothered by humans, who are mostly asleep when the big-eyed squirrels are out foraging for food.

But recent research shows that northern flying squirrels, the species that once dominated Northland forests, are being pushed north at an alarming rate — another victim of a warming climate following other species like moose, lynx and spruce grouse.

One study in Ontario found that southern flying squirrels are moving north — and replacing northern flying squirrels — at a rate of about 12.5 miles each year.

The southern flying squirrels “probably get knocked back a little during the occasional hard winters, but that was the average movement,’’ said Michael Joyce, a wildlife ecologist with the Natural Resources Research Institute at the University of Minnesota Duluth. “That’s really fast. Especially for such a small animal that doesn’t move around much, that has a pretty small home range, that’s a really rapid rate of range movement."

Up and out of Wisconsin, Minnesota?

In Wisconsin, northern flying squirrels held the northern third of the state as recently as 30 years ago when wildlife biology students at the University of Wisconsin-Stevens Point commonly recorded them not far from the central Wisconsin campus.

Now, southern flying squirrels have advanced north all the way to Lake Superior, said Rich Staffen, a zoologist in the Wisconsin Department of Natural Resources’ nongame program. Northerns seem to be vanishing from most of the state.

“In our trapping in the northern third (of Wisconsin) over the past five or so years, we are commonly catching southerns and only very rarely do we catch a northern,’’ said Staffen, who is somewhat hopeful that the southern's preference for hardwoods may offer the northern flying squirrel some bastion of safety in the region's conifer forests.

Whether the shift is happening as rapidly in Minnesota isn’t yet clear. But Joyce is trying to find out, heading a pilot project now to capture both the ultrasonic voices of flying squirrels and to capture their images on trail cameras as well as photo reports from Northland residents.

Northern flying squirrels are listed as a species of concern in Wisconsin and Michigan because of their rapidly shrinking range. So far Minnesota hasn't given the northern flying squirrel any special status. For the most part, the small squirrels have been overlooked by researchers. Now, Joyce hopes to take the first ever comprehensive look at the status of flying squirrels in Minnesota and to confirm if the northward movement of southern flying squirrels is as rapid here as it appears.

Joyce hopes to eventually take a deeper, longer dive into flying squirrel populations, range and trends in Minnesota.

“But first we need some baseline information on just which one is where,’’ he said. “We need to find out what their distribution is across the region now to see how that changes in the future.”

Historically, wildlife biologists declared that northern flying squirrels lived in the northern spruce, pine and fir forests of the northeast, while the southern species dominated the hardwood forests of the central and southeastern counties in the state.

“The historic dividing line was about Leech Lake to Pine City,’’ Joyce said.

But southern flying squirrels have blown past that line and now are found in Duluth and likely up the North Shore, where ample hardwoods like oak and maple trees could give them a foothold. Much of the change, more than 100 miles, has happened in the past 40 years.

“We really don't know how far north they have moved. Our goal is to find that out,’’ Joyce said.

Southerns more aggressive, carry deadly parasite

It’s not that northern flying squirrels have been hugely impacted by the already warmer temperatures in the region. But the milder winters, especially, have allowed the southern species to move north and, for multiple reasons, when the two species overlap the southern one usually wins, even though they are slightly smaller.

Staffen said southern flying squirrels tend to be more aggressive and will kick northerns out of the best nesting cavities in trees. But perhaps more foreboding for the northern subspecies is that southern species often carries a nematode parasite that, while nonlethal to them, is fatal to northern flying squirrels.

Once again, a warming climate opened the door for a new species to move in, bringing problems with it. It’s a similar situation to the northward-moving abundance of deer in Minnesota which have brought a parasitic brainworm with them that’s harmless to deer but fatal to moose.

Northern flying squirrels may be losing out to hybridization, too, much like Minnesota’s lynx forest cats seem to be losing out as bobcat range moves north. And the trend to more hardwood trees in northern forests also favors the southern subspecies, Staffen noted.

You may remember Joyce as the lead researcher on a project building nest boxes for northwoods fishers. For flying squirrels, his goal is to study 10 different areas across the Northeast comparing trail cameras to audio recorders to see which ones best capture flying squirrel numbers. It turns out that the ultrasonic vocalizations flying squirrels make are picked up well by bat voice recorders, or acoustic detectors. (Joyce said the best bait to lure flying squirrels into trail camera range appears to be peanut butter.)

Joyce said the little squirrels piqued his curiosity when they would show up in trail camera photos taken at fisher nesting boxes he’s been placing across the region.

“But what really got me interested in this project was doing some small mammal surveys last fall in an area where I would have expected to see both northern and southern flying squirrels based on their historical ranges in Minnesota. We only saw southerns, which seemed odd to me,” Joyce said, noting it became clear that “the ranges were shifting here — as they are elsewhere — but that there didn't really seem to be as much attention to the situation in Minnesota as in Wisconsin and Michigan.”

Flying squirrels facts There are more than 40 species of flying squirrels worldwide with two of them in Minnesota and Wisconsin — the southern flying squirrel and the northern flying squirrel.

Flying squirrels do not fly, but glide from one perch to another. Their "flight" is made possible by a fold of skin, a membrane which extends from the front to the hind feet. When the legs are outstretched, the skin stretches out tautly to form a large planing surface which enables the squirrel to glide as far as 150 feet, though most glides are between 20 and 30 feet.

Living in tree hollows or leaf nests, flying squirrels are the only nocturnal squirrels in Minnesota, seldom seen during daylight. Southern flying squirrels are found mainly in Minnesota hardwood forests, while the northern subspecies occurs in aspen/pine-dominated forests.

The southern flying squirrel is about the size of a chipmunk, about 9 inches long including the tail and weighing only a couple of ounces. The northern flying squirrel is slightly larger, about 11 inches long and weighing just 3 ounces.

Flying squirrels are noted for their dense fur, glossy olive-brown above and white below, large brown eyes, and mild disposition. Only the shrews and moles have fur that comes close in softness and silkiness to that of flying squirrels. The upper parts are gray-brown, whereas all the lower parts including the tail are white.

Both Minnesota species mate in early spring, and about five weeks later females give birth to three to five tiny, blind young. Southern flying squirrels may have two litters in summer, but this rarely occurs in northern flying squirrels.

Flying squirrels eat a variety of fruits and nuts, insects, small birds and meat scraps. Flying squirrels can be frequent visitors at bird feeders, and some people have lights at the feeders so they can watch the flying squirrel's antics at night.

Small hawks and owls, foxes, weasels and marten are predators of flying squirrels..

Flying squirrels, though unprotected in Minnesota, have no meat or fur value and thus are not hunted or trapped.

Many people who think they see birds flying across highways at night, or around campfires, actually are seeing flying squirrels.

Flying squirrels do not hibernate but slow their body activity in winter and sometimes nest in groups to stay warm.

Source: Minnesota Department of Natural Resources

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