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State of the Boundary Waters: The Wildlife

Excerpt from State of the Boundary Waters Report. Click here to read the entire thing!

 

Some of the plants and animals that call the Boundary Waters home are found nowhere else in the contiguous UnitedStates. The highlight of many people’s trip to the BWCAW includes seeing some of the 50 mammal species found in this wilderness. Fish of cold, deep lakes swim below anglers’ canoes. Large carnivores – wolves, bear, lynx – still make their homes here. Lethal predators and wary prey dance with life and death. Delicate plants and flowers, fleeting insects, and a diverse chorus of birds find the rare combination of water, climate, and food they require to thrive in the Boundary Waters.

Many of the animals that populated what is now the Boundary Waters before the arrival of Europeans are still found here, but they have not been subjected to such significant environmental changes until now. They are sensitive to everything from contaminated water to warmer temperatures, and the survival of many species is not certain.

Minnesota’s mighty moose

Moose stand six-and-a-half feet tall and weigh around 1,000 pounds. They look cobbled together out of leftover parts, but they are well built to survive the harsh conditions in canoe country.

Moose have a hard time handling heat. In the winter, they eat less when the temperature rises above 23 degrees Fahrenheit, and their nutrition and health suffers. In the summer, moose can start experiencing heat stress at about 63 degrees, and begin breathing hard at about 68 degrees – they begin to pant like dogs.

Moose find safety, food, and cooling in lakes and wetlands. In water, moose reduce their respiration rate by almost 30 percent, and their overall energy expenditure by about 10 percent. A moose’s prominent nose is thought to help it forage from the bottom of lakes without inhaling water.

The moose population in northeastern Minnesota, including the Boundary Waters, has been declining rapidly for about 10 years, falling by more than half. While there were 8,840 moose in 2006, there were only 3,710 in 2016. But, the population has stabilized around that level since 2012, and in 2016 the calf survival rate was its third highest since 2005.

The declining population has caused concern with everyone from wildlife managers to moose-loving Minnesotans.

The state of Minnesota, Ojibwe bands, and the federal government have undertaken extensive research projects since 2012 to determine the reason for the moose’s decline. The state’s hunting season was cancelled indefinitely in 2013, while Ojibwe tribes determined that population impacts from harvest by their members would be minimal – and approved a harvest to meet the important cultural and dietary needs of tribal members. Band members continue to harvest the animals based on treaty rights and cultural traditions, providing 400 to 700 lbs of meat from one animal.

How do you feed a half-ton animal?

Summer:

  • Feed for eight hours per day
  • Eat 30 to 40 pounds of aquatic vegetation per day
  • Have four stomachs (like cows) to extract nutrition from massive amounts of plants
  • Chew their cud about 8 hours per day

Winter:

  • Get one-third the nutrition from winter diet of leaves, twigs, and needles.
  • Eat about nine thousand twigs each winter day
  • Due to difficult conditions and inadequate food, they lose weight all winter.

Why are moose populations declining?

Studies show Minnesota’s moose population decline is due to a combination of factors, including parasites, whitetail deer, and predation. Rising temperatures are a key factor in increased moose mortality, as warmer weather in both summer and winter stresses and weakens the animals.

Between 2013 and 2016, scientists determined causes of death for 49 moose. While wolves were the largest single factor, they most often prey on moose that are already weakened by other ailments. Scientists consider wolves to be a minor factor in the population decline, while the key factors are parasites such as brainworm, winter ticks, and liver flukes.

Moose prefer to forage for food on land in recently-disturbed areas of forest. Such habitat can be created by humans with timber harvest, prescribed fire, as well as wildfires and windstorms.

To protect the BWCAW’s iconic moose, Minnesota must address the northeastern region’s deer populations, climate change, and habitat loss.

Canadian Lynx in the Boundary Waters

Canada lynx are medium-sized cats with long legs, large, well-furred paws, long tufts on the ears, and a short, black-tipped tail. They are a federally-listed Threatened Species, and the Arrowhead region of Minnesota, including the Boundary Waters, is designated as critical habitat for the species. Lynx are stealthy and seldom seen, but there is a significant number that call the area home.

Research on the Superior National Forest over the last 15 years shows a strong breeding population. Initial studies led biologists to believe there were few animals living and reproducing in the area. Recent DNA analysis of scat changed that understanding. Analysis reveals at least 92 kittens, 24 breeding females, and 13 breeding males on the Superior National Forest. Researchers call it a “significant reproducing population.”

What does a lynx eat?

Because of the difficulty of access, no surveys have yet been done in the Boundary Waters Wilderness, where scientists anticipate possibly the highest population of the wild cats in the region

Lynx depend on snowshoe hare for food, eating on average one hare every two to three days, especially in winter. They will also eat red squirrels and other animals, but hares are closely connected to the lynx’s life. Adequate hare habitat is essential to healthy lynx populations.

Photo courtesy of Benjamin Olson

When hare densities are low, female lynx have fewer kittens, fewer young survive to adulthood, and lynx populations decline. Lynx and hares are both adapted to deep snow habitats. Snowshoe hares seek dense forest understories for food, protection from predators, and shelter from harsh weather. Early successional forests with brushy ground cover have the most hares.

Lynx also require forests with plenty of downed logs, wads of roots where trees have fallen over, and windfalls for their dens. Ultimately, the availability of both young and old forests are important for their survival.

There are numerous ways that humans affect lynx in northeastern Minnesota. As winters grow warmer, bobcats and coyotes can more easily compete for territory. Bobcats also interbreed with lynx, diluting the genetic pool. Climate change could also mean less deep snow, causing lynx territory to shift north.

The suppression of forest fires and timber management practices can also destroy habitat, while roads and snowmobile trails fragment lynx habitat and provide access to competitors. Over-trapping is a problem in particular during low points in the snowshoe hare population.

Management Methods:

The Superior National Forest identifies these goals for lynx:

  • Identify habitat connections and potential highway crossing areas.
  • Use wildlife fencing, underpasses and overpasses.
  • Reduce incidental take of lynx related to trapping.
  • Prevent barriers to movement in connection areas.
  • Maintain or enhance habitat in connection areas.
  • Pursue opportunities for cooperative management.
  • Conduct landscape-level ecosystem management.
  • Maintain important connectivity with habitat and lynx in Canada.
  • Identify connection areas in land ownership changes.
  • Evaluate land use and exchanges for effects on lynx

The timber wolf — A BWCAW legend

About 2,200 wolves make Minnesota their home, many of them in the Boundary Waters and surrounding region. Wolves in the region are currently listed under the Endangered Species Act.

Gray wolves or timberwolves (Canus lupus) play an essential role in the wilderness ecosystem, hunting whitetail deer, moose, and other herbivores. Hearing their howls is a truly wild experience, and the hope of many people who visit the wilderness.

The BWCAW is one of only two places in the lower 48 states where wolves were never entirely extirpated.

Prior to their federal classification as an endangered species in 1974, wolf hunting was allowed in Minnesota. Their protected status has fluctuated since that time. Wolves were removed from the Endangered Species List in January 2012, and Minnesota allowed hunting and trapping for two years. In December 2014, a federal judge reinstated federal protection for the wolf, and hunting was once again prohibited.

Renewed threats

During the controversial wolf hunting seasons, long-time researcher Dr. L. David Mech suggested the Boundary Waters could serve as a “wolf sanctuary,” prohibiting hunting because the wolves are far from livestock, which they prey on and is the cause of a most human-wolf conflict.

During the 2012 wolf hunting seasons in Minnesota in the northeastern zone, including the Boundary Waters, the harvest target was 117 wolves and 116 animals were killed. In 2013, the target was 65 and 64 animals were killed in the management zone.

Seldom seen species of special concern

These little creatures living in the Boundary Waters and the surrounding area are almost invisible to human eyes. They are all listed by the state of Minnesota as “Species of Special Concern” because of their rarity and sensitivity to change.

  • Northern Bog Lemming (Synaptomys borealis)
    Found in only 10 peatlands in Minnesota, including in the Boundary Waters region. They prefer acidic bogs dominated by sphagnum moss, shrubs, and peat.
  • Smoky Shrew (Sorex fumeus)
    Prefer cool, damp forest floor with a thick litter layer, moss-covered rocks, and decaying debris. Found in Minnesota in glacial boulder streams; second-growth black spruce, fir, paper birch forests; mossy talus slopes; and sphagnum bogs.
  • Eastern Heather Vole (Phenacomys ungava)
    Live in coniferous forests with a heathy understory, wet meadows, rocky hillsides, forest edge, or deciduous shrubby habitats. Needs to be near water, boulders, coarse woody debris, and plants of the heather family.
  • Northern Long-eared Bat (Myotis septentrionalis)
    Designated as a federally-threatened species in 2015 due to white nose syndrome. In summer, bats leave caves for forested habitats where they roost in trees near water sources, and have been documented near the Boundary Waters. A $1.25 million study of their summer habitat is currently underway on the Superior National Forest.[17]
  • Four-toed Salamander (Hemidactylium scutatum)
    Live in mature upland deciduous or mixed deciduous-coniferous forests interspersed with sphagnum seepages, vernal ponds, or other fish-free habitats that serve as nesting sites.