Michigan Nature Monday – Wildlife Corridors

In Michigan’s Eastern Upper Peninsula, one of MNA’s largest conservation landscapes protects a critical migratory channel for rare songbirds and majestic raptors alike. The biological diversity, size, and relatively undisturbed quality of the coastal wetlands and minimally fragmented forests along the St. Mary’s River corridor make this an important conservation area for MNA. Nearly 2,000 acres are protected by MNA sanctuaries in this vast conservation complex.

Two American Kestrels display defensive behavior against an osprey. Photo by Steve Lindberg.

As migratory birds funnel through the St. Mary’s River on their way to wintering and breeding grounds, this connecting waterway between Lake Superior and the Straits of Mackinac provides a globally significant passageway for many rare species. Numerous birds utilize stopover habitat in this corridor including black tern, Caspian tern, osprey, merlin, bald eagle, American bittern, northern harrier, and others.

One sanctuary in the St. Mary’s River Corridor is the 762-plus-acre Schafer Family Nature Sanctuary at Roach Point, which is named to honor brothers Mason C. and Melvin C. Schafer and their family for their many contributions to MNA. The sanctuary contains eight natural communities including Great Lakes marsh, boreal forest, northern mesic forest, northern wet meadow, bog, northern shrub thicket, poor conifer swamp, and rich conifer swamp. Numerous species of wildlife and plants have been documented using the sanctuary including numerous rare species including the Lapland buttercup, black tern, American bittern, bald eagle, osprey, and Alaska orchid.

MNA’s 182-acre Munuscong Lake Nature Sanctuary is just a half mile west of the Schafer Nature Sanctuary. There are significant acreages of wetland along the south shore of Lake Munuscong, from Maple Point on the west and continuing east beyond the mouth of the Gogomain River. These wetlands continue upstream into the Gogomain Swamp – a large, wild, and minimally fragmented swamp of which much is now protected as State Forest. The biological diversity, size, and relatively undisturbed quality of the coastal wetlands and minimally fragmented forests between Munuscong Lake and the Gogomain Swamp make the area an important conservation project for MNA.

The sanctuaries include significant coastal and wetland habitats and help protect a large acreage of northern forest and wildlife habitat. MNA’s Conservation Director, Andy Bacon, explained, “One of the notable features of this area is that it serves as important stopover habitat for neo-tropical and other migratory species. On one site visit, six species of warblers were observed as well as numerous ruffed grouse.”

Beaver dam at MNA’s Carlton Lake Wetlands Nature Sanctuary. Photo by Andrew Bacon.

MNA’s Carlton Lake Nature Sanctuary lies at the southern end of its namesake lake in this corridor with significant acreage of undeveloped open water and wetlands—providing 520 acres of habitat for a great variety of conservation priority bird species. The sanctuary likes within the Great Lakes migratory bird corridor that follows the St. Mary’s River between Lake Superior and the Straights of Mackinac. Birds observed here include the Virginia rail, sora rail, ring-necked duck, green heron, sedge wren, pied-billed grebe, and sandhill crane.

MNA’s Founders 4 the Future Campaign expands the sanctuary to 880 acres, and would further protect the large-scale and primarily undeveloped character of the Carlton Lake complex. This secluded area is beneficial for a diversity of wildlife species considered to be conservation priority species including Michigan threatened least bittern, common loon, Caspian tern, and merlin, as well as the Michigan special concern American bittern, bald eagle, northern harrier, and osprey.

Considered to be a high-quality coastal wetland due to the relatively undisturbed quality and minimally fragmented forests between Lake Munuscong and the Gogomain Swamp to the south, the Rocky Point Wetlands Nature Sanctuary protects an area containing a variety of tree cover and forested community, providing abundant habitat for a diversity of wildlife species considered to be of conservation priority—and importantly, many migratory birds.

The Schafer Family Memorial, nearby Lake Munuscong Nature Sanctuary, and Rocky Point Wetlands Nature Sanctuary together comprise MNA’s Roach Point Conservation Area. Combined with Carlton Lake Wetlands and encompassing nearly 2,000 acres in all, these Conservation Areas represent MNA’s ongoing commitment to enhancing the conservation values and improving the ecological integrity of the nature sanctuaries held within our extensive network.

Michigan Nature Monday: Great Lakes & Fresh Water

The State of Michigan has declared June 3-11 as Great Lakes & Fresh Water Week. So, this month’s Michigan Nature Monday will focus on one of the most important ways that we protect Michigan’s many freshwater resources: peatlands.

What are peatlands? These land-based wetland ecosystems are highly efficient carbon sinks on the landscape—formed by the water-saturated ground which prevents plant materials from fully decomposing. The resulting organic matter is called “peat” and is composed primarily of mosses, sedges, and shrubby material.

Why are peatlands important? Plants absorb carbon from the atmosphere throughout their life through photosynthesis, and when those plants reach the end of their life the process of decomposition releases that stored carbon back into the air. Because the plants that form peat are prevented from fully decomposing, much of the carbon that they have stored remains trapped in the waterlogged conditions of the peatland. It is for this reason that peatlands are known to store more carbon than any other terrestrial ecosystem on Earth, including forests!

One example of peatlands found in Michigan is fens. There are several types of fens found throughout the state and are home to many rare animals such as the yellow rail, Mitchell’s satyr, and eastern massasauga rattlesnake. Fens are extremely fragile and sensitive systems that are already being impacted by climate change. But MNA is working to protect fens all over the state including at our newest sanctuary acquisition in the Eastern Upper Peninsula.

Patterned fens are characterized by ridges and swales that can look like waves on the landscape. Photo by Jason Whalen | Fauna Creative

Fox River Wetlands hosts a variety of natural communities, but none so special as a rare, high-quality “patterned fen”, which is ranked imperiled in Michigan. There are a limited number of these types of fens found in Michigan, and of those, the quality of this complex is ranked in the top ten, making it very important in terms of biodiversity. Protecting the fen and wetlands directly contributes to the pristine water quality of the Fox River.

Patterned fens, also known as a string bog, is a groundwater-fed wetland community found on flat, ancient lakes and outwash plains. Peat forms the soil substrate, and the community displays a series of low-relief ridges (strings) and swales (flarks) that look like subtle waves across the land.

MNA’s largest land protection project in its 70-year history will secure over 5 square miles of habitat and a collection of pristine natural communities, including an incredibly rare and high-quality patterned fen. The 3,436-acre Fox River Wetlands is at the very heart of the storied Fox River watershed, made famous by Ernest Hemingway, and connects to a conservation landscape of over 1 million acres that provides habitat for rare plants and animals of concern in Michigan.

The East Branch of the Fox River, one of just two Michigan Natural Rivers in the Upper Peninsula. Photo by Jason Whalen | Fauna Creative

Comprised of the Main Branch, East Branch, and several other tributaries, the Fox River system is one of only two designated under Michigan’s Natural Rivers program in the Upper Peninsula and only one of 16 across the entire state. The program was created to preserve, protect, and enhance our state’s finest river systems for the use and enjoyment of future generations.

These rivers and the wetlands that feed them are a critical part of the state’s healthy Great Lakes ecosystem. MNA is proud to be part of protecting Michigan’s fresh water through our network of more than 180 nature sanctuaries. Learn more and join us in this work at michigannature.org.

Michigan Nature Monday – Spring Ephemerals

If you’ve spent much time in Michigan, you are likely familiar with the excitement that comes with spring—wildflowers blooming, birds migrating, trees budding. It is a time of renewal and rebirth as the drab browns of winter slowly return to green, the additional sunlight and longer days allowing the process of photosynthesis to recur.

Perhaps the most exciting of all are the ephemerals—the short-lived plants—like spring beauty, trillium, hepatica, and more that provide important food sources for pollinators. These temporary wonders are among the first to appear on the forest floor, anytime between March and June depending on the latitude and elevation. As insects emerge from under leaves where they’ve spent the winter they must go in search of food sources like nectar from these spring ephemeral wildflowers. Widespread and abundant ones like trillium are an easy source for many insects (and birds in search of an insect meal), but there are also some insects that are more particular about the plants they seek nectar from.

False rue anemone and spring beauty in bloom at MNA’s Dowagiac Woods Nature Sanctuary. Photo by Lauren Ross.

It is well-known that monarch butterflies need milkweed for the caterpillar stage of life. Milkweed is actually a toxic plant containing glycosides that would normally make them inedible to people and wildlife, but monarchs have developed a tolerance for this toxin that offers them protective benefits. Birds that eat monarch caterpillars will become sick due to the stored glycosides, and so they learn that the color pattern associated with the monarchs are not a source of food, and will move on.

Another ephemeral plant that blooms later in the summer—the Black-eyed Susan—has a less well-known benefit to Michigan’s federally endangered Poweshiek skipperling butterfly. Adult Poweshiek skipperlings feed exclusively on the nectar of Black-eyed Susan flowers, making these common wildflowers an essential part of the recovery effort for this butterfly.

Poweshiek skipperling butterfly on a black-eyed Susan. Photo by Kelly Nail, USFWS.

So, as signs of spring make their way across Michigan and you delight in the sight of wildflowers blooming, it is a good reminder that these brief encounters are just one of the many important parts of a healthy ecosystem.

~~

Several MNA nature sanctuaries are well-known for their wildflower displays. Dowagiac Woods Nature Sanctuary in Cass County is home to a wide variety of wildflowers including trillium, trout lily, dutchman’s breeches, and many more. Trillium Ravine Plant Preserve in Berrien County holds several different types of trillium that carpet the forest floor for an incredible display for trillium seekers.  Visit michigannature.org to plan your next visit today!

Michigan Nature Monday: Michigan’s Many Water Resources

Michigan is well-known as the “Great Lakes State” but there is much more to the state’s freshwater ecosystem than the massive inland freshwater seas that garner all the attention. There is a true “underdog” in Michigan’s freshwater systems—groundwater.

In honor of National Groundwater Awareness Week (March 5-11, 2023), the Michigan Nature Association is proud to explore a vital component of Michigan’s groundwater system, fens, written by MNA volunteer Zoë Goodrow.

What is a fen?

When the final glaciers in Michigan retreated north about 8,000-12,000 years ago, they shaped landforms that eventually became the wetlands we see today. Fens are among the rarest types of wetlands – more specifically, peatlands – found in Michigan. What differentiates fens from other wetlands is their hydrology.

Fens are fed by a continuous flow of groundwater that filters through nutrient-rich layers of sediment, like limestone, resulting in an ecosystem rich in calcium and magnesium. The steady supply of groundwater into fens means that fen soils remain saturated throughout the year. This causes a reduced abundance of bacteria that break down plant materials (compared to other wetlands), resulting in a buildup of decayed plant debris – also known as peat.

Rare species in fens

Fens have 500 times more rare plant and animal species than the average acre of land in Michigan. They support nearly 60 rare species and are the Michigan equivalent of rainforests in terms of relative biodiversity. Typical plant species that are unique to fens across Michigan include sphagnum mosses, white lady slipper, fringed gentian, edible valerian, and carnivorous plants including sundews and pitcher plants. Rare animals that habituate fens include the yellow rail, Mitchell’s satyr, and eastern massasauga rattlesnake. Fens are extremely fragile and sensitive systems that are already being impacted by climate change, which does not bode well for the rare species that are endemic to fen ecosystems. Because of this, and their significance to Michigan’s biodiversity, it is important to know the guidelines for minimizing disturbance before you visit one.

Types of Michigan fens

Michigan is home to many types of fens, including the northern, prairie, patterned, and coastal fens. These different fens are characterized by the natural processes that formed them and the climatic conditions of the regions they reside in.

Prairie fen photo by Dave Cuthrell.

Northern fens are found in the Upper Peninsula and the northern half of the Lower Peninsula. They occur where a glacial outwash meets a more textured glacial feature like a kettle lake or an end moraine.

Prairie fens, located in the southern half of the Lower Peninsula, occur in former oak-savanna prairies. As their name suggests, they are dominated by a mix of prairie and wetland sedges, grasses, and forbs. These fens were formed via the same glacial processes as northern fens.

Patterned fens, also known as string bogs, also occur in the Upper Peninsula. What differentiates these fens from northern fens is that they are a series of alternating ridges and hollows, oriented parallel to the contours of the land. The natural processes responsible for forming these unique systems are still unknown. While there are several proposed hypotheses – researchers agree that an essential factor is the direction of water movement, as the ridges and hollows are consistently oriented perpendicular to the flow of groundwater. (See more on patterned fens with MNA’s Fox River Wetlands in the video linked below)

Click on the image above to watch “The Fox and the Fen”. Photo by Jason Whalen, Fauna Creative.

Coastal fens occur along Lake Michigan and Lake Huron in the Upper Peninsula and northern Lower Peninsula. The natural processes that formed them are inextricably linked to those of the Great Lakes. The water tables that influence these systems are subjected to seasonal and multi-year lake level fluctuations, so vegetation in coastal fens changes quickly when water levels change.

—

To experience a fen habitat first-hand, consider visiting MNA’s Lefglen Nature Sanctuary in Jackson County. The sanctuary is home to a prairie fen and a natural flowing well visible from the south trail. Visit our online sanctuary map for directions and more information.