Dangerous Migration: One of Nature’s Most Impressive Migration Phenomena is at Risk

By William Rapai

 

*The following story appeared in the Fall 2017 edition of Michigan Nature Magazine

monarch - Wendy Caldwell, Monarch Joint Venture

Many flowers—especially native plants—are terrific sources of nectar for monarch butterflies. Photo by Wendy Caldwell, Monarch Joint Venture

It’s September at the Michigan Nature Association’s Goose Creek Grassland Sanctuary.

Even though asters and goldenrod are in bloom, most plants that grow here—including the three species of milkweed—are in decline. 

Hanging from the underside of a leaf, a Monarch butterfly emerges from its chrysalis, with an urge to do only one thing: fly to Mexico.

Five generations of Monarchs have hatched already during this calendar year, but this individual is different. Always synchronized to the lifecycle of the milkweed, this Monarch inherently understands that fall is approaching and it must go. 

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Monarch butterflies are not able to survive the cold winters of most of the United States so they migrate south and west each fall to escape the cold weather. They travel much farther than all other tropical butterflies, up to 2,000 miles. They are the only butterflies to make such a long, two-way migration each year. Map courtesy U.S. Fish and Wildlife Service

There are no roadmaps or guideposts for the Monarch and there will be no adults that have made the journey before to show the way. There is only an inner drive that guides the butterfly on a 2,000-mile journey south and west, across the corn belt, the hot, dry plains of Oklahoma and Texas, across the Rio Grande, and over the mountains of Mexico to a place it has never been before—the Monarch Butterfly Biosphere Reserve west of Mexico City—where it will spend the winter in hibernation.  

There are Monarchs all across the United States and the southern tier of Canada and biologists split them into two populations. The western population winters in southern California and spreads out across the west coast and the Great Basin in the summer. But the eastern population—those butterflies east of the Rocky Mountains—return to Mexico in the fall in one of the most astonishing natural phenomena on this planet. Other butterflies migrate—both north in the spring and south in the fall—but the Monarch’s journey is unique because of the distance and the entire population somehow finds its way to one location in the mountains of Mexico after being spread out across half of North America. 

 

Reason for Alarm

This eastern migratory population is in jeopardy, however. The Monarch’s population is in trouble, caught in the crossfire of changing land use and habitat loss, drought in the southern plains, dangerous pesticides, and extreme storms. In the early 1990s, the eastern population of the Monarch was estimated at more than 500 million individuals. By 2014, that number had fallen to about 34 million. The population has rebounded somewhat since then—to an estimated 56 million in 2015, according to Chip Taylor, the director of Monarch Watch at the University of Kansas.

Even though the numbers have perked up, there is still much reason for concern. A 2016 study of this population by the Scripps Institution of Oceanography at the University of California at San Diego and the U.S. Geological Survey concluded that it could go extinct sometime in the next two decades. In fact, the eastern Monarch population decline has become such a concern that in 2014 President Barack Obama issued an executive order to create the National Pollinator Task Force to develop an action plan to save declining populations of honeybees and restore the eastern Monarchs to about 225 million. 

The Monarch’s population crash has increased the importance of sanctuaries like the Goose Creek Grasslands. This 70-acre sanctuary is just a postage stamp on a landscape dominated by agriculture, but it has everything a Monarch needs: flowering plants that provide nectar and plentiful milkweed, which is the only food source for Monarch larvae. This place also has sanctuary manager Rachel Maranto and many generous volunteers who work hard to remove glossy buckthorn, an invasive plant that would grow property line-to-property line and quickly dominate the entire landscape if not controlled. 

The on-the-ground work at the Goose Creek Grasslands is representative of the commitment the Michigan Nature Association has made to the Monarch. MNA has been working with the Michigan Department of Natural Resources and other government agencies, non-profits, and citizens to promote the health of the Monarch by promoting the planting of additional nectar plants and milkweeds.

Nectar gardens are particularly important for the Monarch’s fall migratory generation. Weight gained by those butterflies during migration will have to sustain them because they won’t eat anything until they come out of hibernation in March, says Cora Lund Preston, a communications specialist with the Monarch Joint Venture, a Minnesota-based partnership of more than 60 organizations.

There’s one more thing unique to this fall migratory generation: for their entire migration and hibernation, they are locked in a juvenile state called “diapause,” which makes them unable to breed. Always synchronized to the milkweed, they only become adults and breed after they emerge from hibernation in March as milkweed plants sprout in Mexico and Texas. 

But all that is months ahead for this Monarch. It’s a sunny September day, and the Monarch is torn whether to leave Goose Creek. Michigan is a pretty good place for a Monarch in any generation, says Stephen Malcolm, a professor of chemical biology at Western Michigan University. The landscapes of states to the south and southwest—Ohio, Indiana, Illinois, and Iowa—are a vast monoculture of corn and soybeans that provide very little in the way of food or places to breed.  Michigan’s less agriculturally intense and more complex environmental matrix is good for Monarchs because it provides more places for milkweed and nectar plants to grow. In addition, the moderating impact of the Great Lakes limits temperature extremes. 

monarchs at Fred Dye by Adrienne Bozic

Monarch butterflies at MNA’s Fred Dye Nature Sanctuary in Mackinac County. Photo by Adrienne Bozic.

Despite those luxuries, migratory restlessness is too much to overcome and this Monarch lifts off from a goldenrod, to start a perilous journey. This trip would be dangerous for any animal let alone one that weighs only about a half a gram—a hundred times as heavy as a grain of sand. There are predators and the risk of being struck by a speeding vehicle or being caught in an early frost. 

 

Near Impossible Challenge

Like other Monarchs traveling across the Midwest, this butterfly’s first challenge is finding food on a vast landscape of corn and soybeans. Often there are flowering plants growing along rural roads—New England aster, stiff goldenrod, black-eyed Susan—but there’s also danger here. If the plants are near an agricultural field there’s a chance they have been contaminated with neonicotinoids or some other insecticide. 

Neonicotinoids are considered harmless to humans in small amounts, but to insects like butterflies and honeybees they are deadly. The pesticide is systemic, which means it reaches into all parts of the plant and kills any insect that comes in contact with any portion of the plant. Many of the corn and soybean seeds planted across the Midwest are treated with neonicotinoids, and the insecticide is absorbed as the plant germinates and grows. Other neonicotinoids are sprayed on plants or are included in irrigation water, which unfortunately allows them to spread to nearby non-agricultural plants. For a pollinator like a honeybee, even a minute amount is lethal.

For the Monarch, however, the impact of neonicontinoids will be fully felt when a new generation arrives back in the Midwest the following spring. A 2015 U.S. Department of Agriculture study showed that even if milkweeds are not treated directly, they can contain neonicotinoid compounds in levels high enough to be fatal to Monarch caterpillars if they grow near treated agriculture. (You may very well have a neonicotinoid compound in your house even if you pride yourself on not using pesticides on your garden. Have a dog or cat? If it wears a flea or tick collar, it likely has a neonicotinoid as an active ingredient.)

California monarch - Wendy Caldwell, Monarch Joint Venture

Mountains west of Mexico City are the winter refuge for most of the monarch butterflies in North America. Photo by Wendy Caldwell, Monarch Joint Venture.

As the Monarch approaches the Rio Grande, it and other migrating Monarchs from across the eastern United States funnel into a narrow corridor that parallels the Gulf of Mexico. There are two dangers here: drought and tropical storms. A four-year drought in this area earlier this decade took a severe toll, as Monarchs were unable to find food as they traveled through the area. In 2011 alone, 97% of Texas was in drought with 88% of the state experiencing severe drought. 

Mexico - monarchs on trees - Wendy Caldwell

After migrating from the United States and Canada, monarch butterflies spend the winter in oyamel firs at a few mountain forests in Mexico. Photo by Wendy Caldwell, Monarch Joint Venture.

That drought also had an impact for three straight springs: Monarchs emerging from hibernation in March went north expecting to find young milkweed plants growing so they could breed and lay eggs and for three straight years there were almost none. A wet spring in Texas in 2015 gave the migrants a bumper crop of milkweed, and the Monarch population responded accordingly. 

And then there is the danger of running headlong into a tropical storm entering Texas or northern Mexico from the Gulf of Mexico. Biologists say it’s common for Monarchs to survive the heavy rains and high winds by burying themselves in leaf litter, hiding under rocks, or taking shelter in a hollow part of a tree. 

Ten weeks after it left Goose Creek, this Monarch has made it safely to the Monarch Butterfly Biosphere Reserve in central Mexico. Technically this reserve is a tropical resort—only about 19 degrees north of the Equator—but at nearly two miles above sea level, the area has a unique microclimate and winter temperatures range between 32 and 60 degrees Fahrenheit. The butterflies cluster together on the branches of evergreen trees to keep warm.

But this clustering—the entire population in less than 50,000 acres—makes the Monarchs vulnerable. A storm in early March 2016 brought cold temperatures and high winds that knocked down about 133 acres of trees and killed an estimated 6.2 million butterflies. 

 

A Cycle Worth Saving

In March, the sun climbs higher overhead, the thin mountain air begins to warm and millions of Monarchs emerge from hibernation and search for food. No longer in diapause, they now also search for mates and milkweed plants to lay their eggs and continue the butterfly’s lifecycle. 

There will be as many as five generations during the year as the Monarch again spreads out across eastern North America, reaching Michigan and the Goose Creek Sanctuary in early May. 

And on a late summer day, with the milkweed in decline at a sanctuary in southern Michigan, a Monarch will emerge from its chrysalis, with an urge to do only one thing. 

monarch on a goldenrod - Wendy Caldwell, Monarch Joint Venture

A monarch butterfly rests on goldenrod before continuing toward its migration destination. Photo by Wendy Caldwell, Monarch Joint Venture. 

William Rapai is the author of two Michigan Notable Books: The Kirtland’s Warbler (University of Michigan Press) and Lake Invaders (Wayne State University Press). He is also the president of Grosse Pointe Audubon and has a milkweed/pollinator garden in his front yard.

Celebrating Bat Week 2019

by Sarah Royalty Pinkelman & Michigan Nature Association

Word has spread about the essential pollinating behavior of bees and the seed-spreading habit of birds, but the bat, the only flying mammal, is also a significant player in the ecology of animal and plant mutualism. In warmer climates, bats play a similar role as bees and hummingbirds, drinking nectar and pollinating blooms that produce fruits like the banana and agave. Colder climates like Michigan provide a home for insectivorous bat species that consume a significant number of insects that harm humans and plants alike.

Michigan has nine different bat species, but Michiganders most often encounter the little and big brown bats. We see them at dusk gulping insects at a voracious pace, eating from 600 to 1,000 per hour. A mother supporting her young can eat more than her body weight in insects in a single night.

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A big brown bat at the Leslie Science & Nature Center. Photo courtesy Sarah Royalty Pinkelman

In fact, bats such as big browns feed on specific mosquito species that are vectors for many diseases, including Eastern equine encephalitis. Michigan’s bats also help clear the air of corn and soybean crop–eating insects. While healthy bat populations save the farming industry billions of dollars a year in pesticide use, their benefit to Michigan’s ecology is priceless; by reducing the need for agricultural pesticides, eating disease-carrying insects, and holding a key spot in the nocturnal food web as predator and prey, they’re an integral part of a healthy ecosystem.

Like many species across the globe, bat numbers are declining. Two Michigan species are endangered (the northern long-eared and Indiana bat) and others may follow. A top threat is White-nose Syndrome (WNS), or Pseudogymnoascus destructans. Dr. Allen Kurta, an Eastern Michigan University researcher, has called it the most devastating wildlife disease North America has faced since European arrival. More than 6.7 million bats have been lost to the disease continent-wide since its arrival in New York in 2006. The disease repeatedly wakens hibernating bats, draining their energy in winter when there’s no food available. Most infected bats die from starvation. Dr. Kurta cites an 83% decline in bats since the arrival of WNS.

There are several ways to support our bat populations, and habitat protection is primary. For example, in winter bats hibernate in caves, structures, and abandoned mines, and it is vital to respect the signage at these sights. There are a number of steps you can take at home to help bats, learn more about these and International Bat Week at batweek.org.

The Michigan Nature Association works to protect habitat for rare, threatened, and endangered species across the state. By protecting habitat for target species, we are benefiting the broader population of plants and animals that call Michigan home. Join us on October 24th, 2019 at the Red Cedar River Plant Preserve in Williamston, Michigan with a bat expert from the Bat Association of MSU for our Bat Week Walk, exploring what makes a good bat habitat, and learning more about this ecologically important species. For more information about this event, contact us at michigannature@michigannature.org or 866-223-2231.

bat week walk photo by Keith Saylor

The Michigan Nature Association & Bat Association of MSU will be holding a Bat Week Walk at MNA’s Red Cedar River Plant Preserve on Thursday, October 24th, 2019.

Coastal Sanctuaries Protect Changing Shorelines

With ever-fluctuating weather conditions, and uncertainty in how climate change will affect water levels in the Great Lakes basin, the work that MNA is doing to protect habitat for rare, threatened, and endangered species is now more important than ever.

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Volunteer Ashley Schilling uses her hand as a measurement for the dwarf lake iris.

One of several coastal sanctuaries that MNA currently maintains is the Spitler Shore Nature Sanctuary in Presque Isle County. This 50-acre sanctuary includes more than 1,500 feet of Lake Huron shoreline, and contains populations of the federally threatened dwarf lake iris. This sanctuary’s habitat, like much of the Great Lakes shoreline, is at risk from extreme and unpredictable fluctuations in water levels, affecting much more than just its magnificent sunrise views.

During the period between 1998 and 2012, Lakes Michigan and Huron experienced persistently low average water levels. This was due in large part to increased evaporation – to which the lakes are susceptible whenever they are not covered by ice. But the winter of 2013-14 brought extended periods of extreme cold, resulting in increased ice cover and protecting the lakes from the much of this evaporation. Since that time, all of the Great Lakes have risen to record-high average levels, the product of both limited evaporation, and heavy precipitation and runoff from the many rivers and streams that feed the lakes. Water levels in 2019 have proven to continue this trend of new record highs, with meteorologists having estimated a 10-inch rise on Lakes Michigan and Huron through July (representing 8 trillion gallons of water) – the lakes were recorded at 13 inches above their 2018 levels, by the end of June.

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Many shipwrecks and their associated debris were newly uncovered during this reduction and influx of water along the shorelines of Huron and Michigan. The photo here shows some of these shipwreck timbers which today rest peacefully once again underwater, discovered by a father and daughter from Camp Chickagami. Photo by John Porter.

These extremes have had profound effects on developed shoreline statewide, with much of Belle Isle being inundated with rising St. Clair River water, and roads in the Upper Peninsula at risk of eroding into Lake Superior. The impact on non-developed shoreline, like that found in Spitler Shore Nature Sanctuary, is yet to be realized, but it is now more clear than ever that these spaces need protecting, so that they can continue to support the diversity of plant and animal life required for a healthy ecosystem.

You can learn more about MNA’s statewide nature sanctuaries online at michigannature.org.

Estivant Pines 45th Anniversary Challenge

2018 marks the 45th anniversary of a remarkable example of what people can do when they join together to make a difference. In August of 1973, after a statewide campaign rallying the support of people across Michigan, MNA prevented Michigan’s largest remaining stand of old growth white pine forest from being destroyed forever. Because people across the state helped MNA purchase the land, nearly half-a-century later you can visit MNA’s Estivant Pines Nature Sanctuary, walk its trails, and experience first-hand a majestic virgin forest that has been undisturbed for hundreds of years.

This year, MNA received a special challenge in honor of the 45th anniversary of the campaign to save Estivant Pines from logging. The grant will provide the $90,000 we need to purchase 60 acres along the southern border of Estivant Pines, but only if we show strong statewide support by raising an additional $90,000 for general stewardship.

Support Protecting Michigan Nature this #GivingTuesday

We need 45 individuals to give $100 between now and midnight Tuesday, November 27. As an added incentive, your $100 gift will be matched dollar-for-dollar. Donate to help save the Pines!

Expanding a 510-acre Living Museum of Michigan’s Old White Pine Forests

The majestic white pines at Estivant were once slated for logging and would have been lost were it not for MNA’s members, donors and volunteers who answered the call of concerned locals to save this Michigan natural treasure.

No single project has introduced more people across Michigan (and the nation) to the work of MNA and the importance of protecting Michigan’s natural heritage than Estivant Pines.

And there is no more inspiring example of what MNA can accomplish when we all pull together than the successful effort to protect Estivant Pines.

So much more than the white pines were saved! The dense, old growth forest canopy provides habitat for 85 species of birds, including 15 species of warblers. Many other animal species that prefer a mature forest habitat utilize these unique woods, including the pine marten. The pine marten was nearly eliminated from Michigan’s northern forests in the early 20th century.

Below the towering trunks of the pines live an astonishing array of wildflowers, such as asters, baneberry, pyrolas and twinflower. More than a dozen species of orchids and over 23 species of ferns, including spleenwort, maidenhair and holly fern, are also scattered across the forest floor.

Adding 60 Acres Near Where the Eight-Foot-Diameter “Leaning Giant” Once Stood

The additional 60 acres comes in two tracts, one on either side of the old growth white pine forest where the Leaning Giant was found years ago. Many of the more adventurous visitors to Estivant Pines Nature Sanctuary take a rough and rugged hiking trail and cross the Montreal River to see the famous Leaning Giant, a celebrated white pine with a trunk eight feet in diameter. Named a Michigan champion white pine in 1971, the Leaning Giant was later brought down in 1987 by a fierce north wind but you can still see its massive trunk lying across the forest floor today.

With your support, we can meet this ambitious challenge and acquire this remarkable property. Along with old growth white pines, the 60 acre property contains large cedar and eastern hemlock trees and would serve as an important buffer to the heart of Estivant Pines. Wetlands found on the property are integral to the hydrology of an emergent wetland on the existing sanctuary that is regularly used by American bittern, a species of special concern in Michigan. Acquiring the 60 acres would also ensure the protection of a half mile of the Montreal River with frontage on both sides.

The Natural Fall Transition

By Abby Pointer, MNA Intern

As our summer slowly shifts into Michigan’s favorite season, the humidity will disappear into a brisk breeze and leaves will turn happy orange and red. You might partake in festive, nature oriented activities such as apple picking, birding, or fall color walks. Our reason for doing this is to enjoy some time with friends and family, but have you thought about the reason why nature acts as it does in the fall?

Migrating-Birds-Swans-Bill-and-Sharon-Draker-Rolfnp-comSince Autumn is a transitional season, often the plants and animals we see are in a transition period as they prepare for a long winter. For instance, birds are migrating back from their summer homes to somewhere less chilly for the winter. To many avid birders’ delights, we are lucky in Michigan to be able to see rare species such as warblers, vireos, and thrushes migrating. If you visit Whitefish Point, it is an excellent place to spot the migrating loons and, if you look towards the skies, you might also spot the soaring wingspans of sharp shinned hawks, bald eagles, and ospreys.

While the birds fly south, mammals take advantage of fall fruiting trees and plants. Species such as squirrels, chipmunks, and even bears might be more active as they prepare themselves for winter by gathering food and preparing nests or dens. Many types of berries and nuts ripen for consumption in the fall, and as the temperature cools, fungi also begin to sprout. The production of berries, nuts, and seeds this time of year cleverly coincides with the time that birds are stopping to snack during migration and when small mammals bury nuts for sparser months. These fruits and nuts are the structures that enable the dispersal of seeds, so these animals in transition are essential in the process of creating new plant life for some tree and shrub species such as red chokeberry, blackhaw viburnum, and common ninebark. Acorns from oak trees and hickory nuts serve the same purpose and are spread by small mammals in a process sometimes known as “scatter hoarding”.

lefglen nsWhile animals collect the nuts from trees for winter hibernation, the trees themselves have a very charismatic process that prepares them for their own kind of hibernation. During the winter months, deciduous trees go into a period of dormancy where they survive off the energy they stored during the sunny summer months, and they drop their leaves that contain chloroplasts (structures that turn light from the sun into plant food) to conserve energy. Leaves of trees can sense a shortening period of daylight, and eventually stop producing the chemical chlorophyll that make leaves green, and then we can see bright colored pigments such as orange and red that were previously masked by green all summer. We see the best fall colors when there is a wet growing season followed by a cool, frostless fall. Visit an MNA sanctuary to see this trees in action. Enjoy the colors!

Protecting Michigan Turtles

By Abby Pointer, MNA Intern

In the state of Michigan we are lucky to be the home of multiple turtle species, from the common snapping turtle to the red-eared slider. With such a diverse potential for habitat, turtles can live in woodlands, grasslands, lakes, rivers, wetlands, and even cities. Unfortunately, some turtles with more specific needs are suffering from habitat destruction and loss, making their survival a bit more difficult. Three of these critters are species of concern, which dictates that they are in need of specific conservation actions, and one species is currently threatened, which is a warning that it is on the brink of becoming endangered. An important way to help conserve these turtles is education, so let’s take a minute to learn how to identify these turtles and their habitat.

eastern box turtle

Eastern box turtle

The first of the four is the eastern box turtle, one of the three species of special concern. Recognized by a helmet-shaped shell with yellow and orange blotches, the eastern box turtle prefers moist, deciduous woodlands with sandy soils and ravines or slopes. Historically, they have been common in eastern Lake Michigan and western Lake Erie woodlands but numbers are steadily decreasing.

 

 

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Blanding’s turtle

Blanding’s turtle, on the other hand, prefers more wetland habitat, a habitat itself that is in need of conservation effort. These turtles can be found in shallow weedy waters of wetlands, marshes, and swamps. Their shell is tall, domed, and of darker coloration. The rest of the skin is also darker, and the under part of its body and neck is a bright yellow color.

 

wood turtle

Wood turtle

The Wood turtle prefers low disturbance, and because of that the species is now quite uncommon in the Great Lakes region. For most of the year, they reside in sandy bottom streams or rivers, but are terrestrial in the summer. Shells of wood turtles are brown or grayish brown, that sits low and central on their back. Their head, legs and tail are typically black while the softer parts of their body are a yellow color.

 

While the previous three turtles were species of special concern, the Spotted turtle is the one threatened turtle in Michigan. These turtles live in clear shallow water with mucky bottoms and much vegetation. Their populations are typically isolated and are found surrounded by areas of unsuitable habitat, and are unfortunately quite rare in the Great Lakes region. These turtles, like their name, are distinguished by small bright yellow spots on their dark colored shell.

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Spotted turtle

Many of the turtles mentioned above are threatened by wetland drainage and other types of disturbance such as pollution, nest predation, and over-harvest. One of the best ways you can help protect these species is by helping joining a conservation organization, such as the Michigan Nature Association, that supports efforts to protect their depleting habitat. Learn more about protecting and identifying your local turtles by visiting www.herpman.com.

Walk to Big Valley

Walk to Big Valley
Thursday, July 26
6:00 – 8:30 p.m.
Rose Township Hall
9080 Mason St, Holly, MI

Join the Rose Township Heritage Committee along with the Michigan Nature Association for a nature and historical walk from the Rose Township Hall to an overlook of the Big Valley Nature Sanctuary – home to a high quality prairie fen (a unique and rare type of wetland with an array of interesting native plants and animal species including a small butterfly that is federally listed as endangered).

The program is for all ages (and free) and will begin with a short presentation in the lower level of the Rose Township Hall located at 9080 Mason Street. Afterwards there will be about a 2 mile walk (round trip). While walking we will pass one of the township’s historical homes with a very interesting history and some interesting geological features. Refreshments will be served. Wear comfortable walking shoes and clothing.

Please RSVP to Dianne Scheib-Snider, dianne@rosetownship.com, 248-634-6889

Big Valley