Fireflies are a well-known member of the beetle family that live all across the United States. Including the estimated 170 species in North America, there are over 2,000 species of fireflies worldwide on every continent except Antarctica. Their wondrous bioluminescence is a special sight to behold, admired by children and adults alike. Michiganders may recall summertime memories of running around their backyard with joy searching for these creatures, waiting for the next tiny glow to illuminate the night. As it turns out, that unique glow is not just a feature of the adult firefly: the firefly eggs and larvae can glow too!
Firefly adult beetle at MNA’s Clifford R. and Calla C. Burr Memorial Nature Sanctuary. Photo by Angie Adamec.
Fireflies begin their lives as small eggs, sometimes clustered together with up to 100 other eggs. These firefly eggs can be found in moist soil or vegetation during the summer where they develop for about a month. For some species of firefly, these eggs will emit a dim glow.
As the summer turns to fall, the firefly eggs transition to their next stage of life and become larvae. They live as larvae throughout the fall, feeding on insects, worms, and snails. As the winter approaches in Michigan, they survive the cold temperatures by burrowing into the ground where they stay dormant for several months. The larvae then emerge from the ground in spring. Firefly larvae, much like they did as eggs, can produce light. However, unlike firefly eggs and adults, which may or may not emit light, all species of firefly larvae glow. Hence, they are often referred to as ‘glowworms’ in this stage of their lives. The naturally occurring chemicals in firefly larvae give them a bitter taste, making them undesirable as prey. Thus, some scientists believe glowworms are bioluminescent to warn potential predators of their bad taste. The beauty of the glowworm is only magnified by the rarity of actually encountering one, as they are more difficult to stumble upon compared to the adult fireflies that dance through the night sky.
Firefly larvae emit a bioluminescent light to warn potential predators of their unsavory taste. Photo by Alexandra Karelian via Adobe Stock, @karelian – stock.adobe.com
The glowworms pupate later in the spring and emerge as adult fireflies, on average, a few weeks after pupation. Once fireflies have reached their adult stage, they only live for a few weeks to a month. Therefore, a firefly’s main goal is to reproduce within that short lifespan. As adults, some fireflies produce light and others do not. Those that do typically only illuminate for mating proposes, yet they have also been observed to do so for other reasons, like defending territory. The male firefly will fly around, flashing a specific light pattern to attract a mate. The female will then flash her own signal, indicating her interest in that male. Adult fireflies that do not produce light instead use pheromones to find mates and reproduce.
As many have never had the chance to see a firefly in a pre-adult stage, it may be surprising to discover that fireflies begin glowing so early. Those who have witnessed one are certainly lucky!
Today, May 21, 2021 is National Endangered Species Day. Michigan is home to nearly 30 plants and animals that are listed on the federal endangered species list. MNA works to help these species recover by protecting habitat that is critical to their survival, and by educating the public about each of their crucial roles in the environment. One of the ways that we accomplish that goal is by hosting our annual Race for Michigan Nature series of 5Ks throughout the state.
Each 5K promotes one rare, threatened, or endangered species native to Michigan, and new for 2021 is the introduction of the Virtual 5K promoting all six species in the series. Each of these species and a brief description is found below.
Species Spotlight
Karner Blue Butterfly The Karner blue butterfly was federally listed as an endangered species in 1992 due to habitat loss, climate change, and collection. Habitat throughout the butterfly’s range has been lost due to land development and lack of natural disturbance, such as fire and grazing by large mammals. Such disturbances help maintain the butterfly’s habitat by setting back encroaching forests and encouraging lupine and flowering plant growth. Another notable threat is climate change, which is playing a role in the growth, development, and reproductive patterns of the Karner blue butterfly. A third problem is illegal collection due to the Karner blue butterfly’s rarity and beauty. Because butterfly numbers are so low, the collection of even a few individuals could harm the butterfly population. Collection is illegal without a permit.
Karner blue butterfly photo by Valerie Lindeman
Monarch Butterfly With a historic range spanning over 3,000 miles across North and Central America, as well as the northern part of South America, the Monarch butterfly is the most well-traveled, and one of the most recognizable of the butterflies. Every spring, millions of these winged wonders make the journey north as far as Canada from their wintering spots in Mexico. Largely the result of habitat loss, there has been a nearly 90% decline in the population of the Eastern monarch, which is the largest subset of the species and that which carries its migration into Michigan. This is a grave concern, as pollinators supply 1/3 of the world’s food and 3/4 of its flowers, and apart from being lovely, Monarchs are one of the most common and widespread butterfly species. Several initiatives are underway to preserve the necessary habitats to sustain their populations, including the Monarch Joint Venture and Journey North.
Monarch butterfly photo by Adrienne Bozic
Moose Moose are native to Michigan and occurred throughout nearly the entire state prior to European settlement. Moose disappeared from the Lower Peninsula in the 1890s, and only a few scattered individuals remain in the Upper Peninsula. One cause was from extensive logging during the early 20th century eliminating millions of acres of moose habitat. Loggers, miners, and other settlers also took these large animals for food. Another contributing factor was brain worm, a fatal neurological disease in moose. Climate change is also a significant factor as it is slowing altering habitat to be less favorable to moose, expanding the range of white-tailed deer north, which transports the brain worm and increases tick and parasite survival ultimately having a negative impact on the moose population. Fun fact: Moose is an Algonquin term that means “twig eater”.
Moose photo from MNA Archives.
Eastern Box Turtle The eastern box turtle is known for its high-domed carapace (top shell). The shell has irregular yellow or orange blotches on a brown background that mimic sunlight dappling on the forest floor. Eastern box turtles live in open woodlands and adjacent meadows, thickets, and gardens with sandy soils for nesting, which are often near shallow ponds, swamps, or streams. It is Michigan’s only truly terrestrial turtle. Box turtles are omnivorous and will feed on a variety of food items, including earthworms, slugs, snails, insects, frogs, toads, small snakes, carrion, leaves, grass, berries, fruits, and fungi. Eastern box turtles are uncommon to rare in the southern and western Lower Peninsula. Their populations are declining due to habitat loss, collection for pets, and road mortality. Box turtles are protected by Michigan law as a special concern species.
Eastern Box Turtle from MNA Archives
Lake Sturgeon Despite their name, lake sturgeon are also found in rivers. Sturgeon prefer large shallow lakes and rivers and the Great Lakes shorelines. They are a bottom-dwelling nearshore fish that live at water depths of 15 to 30 feet and prefer the cobbly unvegetated run and pool habitats. The lake sturgeon was once located throughout the Great Lakes, but over-harvest by European settlers, destruction of food sources, invasive species, and dam construction on spawning rivers have all had an impact on their survival. Lake sturgeon are currently listed as a state threatened species. Conservation of this ancient species will be dependent on strict control of harvests and protection of spawning rivers and fish during spawning periods. The State of Michigan prohibits commercial fishing for lake sturgeon and closely regulates sturgeon sport fishing.
Lake sturgeon photo by Michael Thomas
Eastern Massasauga Rattlesnake
The eastern massasauga rattlesnake has been listed as a federally threatened species under the Endangered Species Act. The rattlesnake requires federal protection due to eradication, habitat loss, snake fungal disease, and lack of management, which results in excessive shading as habitat shifts toward forest. As an indicator species, the fact that massasaugas are in serious decline is a warning bell indicating additional problems. By protecting massasaugas, we conserve natural systems that support many species of plants and animals. Massasaugas live in wetlands including wet prairies, marshes, fens, and low areas along rivers and lakes. They often hibernate in crayfish burrows but may also be found under logs and tree roots or in small mammal burrows. Unlike other rattlesnakes, massasaugas hibernate alone.
Eastern Massasauga Rattlesnake photo by Zach Pacana
You can help us promote the need to protect habitat for the state’s most vulnerable species by sharing this post with your friends!
March signals the end of another winter, woody invasive shrubs removal season. It is not exactly a season noted on the calendar or managed by regulators, but is well known to many volunteer stewards. For me the season begins when the trees have lost most of their leaves in late fall and ends as sap begins to swell overwintered buds in early spring. As I recently toured a prairie fen I steward noting this season’s piles of cut invasive shrubs and open canopy, I was excited for the restoration work completed. I was also saddened to see another season go, even though I knew it meant spring was around the corner.
Before restoration work. Photo by Dan Burton.
There is something about this restoration work that I find very rewarding. It is tough physical work in cold winter conditions, but I am still drawn (if not addicted) to it. Part of the draw is working outside immersed in the natural elements that awaken dormant senses not unlike the hours I spend hiking and canoeing. Part of it is the physical tasks that drain my ageing body’s meager energy reserves taking with it pent-up anxiety from everyday life and yet somehow leaving me recharged. Part of it is the positive feeling of helping out an underdog prairie fen as it fights off a formidable foe in invasive shrubs. The prairie fen has historically had the help of fire in this battle, but that friendly partner has been mostly absent these days and sorely missed by many of the prairie fen’s native flora and fauna that benefit from the open canopy created.
Another part is the human elements I find outdoors even when working solo. I usually get to work with some dedicated like minded volunteers and enjoy the camaraderie, but COVID restrictions made this a solo season. As this season came to an end and I looked around the prairie fen I had worked so hard to help in its struggle against invasive intruders, I found myself alone and thinking about my stepdad and his brother who introduced me to the outdoors as a kid. They are both gone now and in some way, I think I was hoping they would be proud of the restoration work, its benefit to wildlife, and how they played a role in it by introducing me to the outdoors so many years ago.
After restoration work. Photo by Dan Burton.
As I rested on a weathered downed tree tossing back trail mix, faded fond memories of early morning fishing and hunting trips with the two of them drifted in lifting my spirits. They would be proud of the restoration work, but being old school they likely would have questioned my sanity. It does seem crazy to think of the hours, effort and resources I put into volunteer stewardship, yet I benefit as much as the prairie fen and its fantastic native flora and fauna. I guess you could simply say I am in a symbiotic relationship with a pretty prairie fen and thankful for its many mutual benefits.
Learn more about how you can become a Sanctuary Steward with MNA and start nurturing your symbiotic relationship today at michigannature.org.
A vernal pool fills with water around the springtime, bringing new life. Here, a small crustacean hatches; a lesser known relative of the lobster.
This crustacean’s common name, fairy shrimp, is the perfect nod to its graceful demeanor in the water and its small, delicate body. These aquatic dancers glide through the water on their backs by slowly rippling their eleven pairs of legs to create propulsion. They vary in size but are typically around three quarters of an inch long.
Fairy shrimp photo courtesy Michigan Natural Features Inventory.
The fairy shrimp would not be able to survive without the protective habitat created by the emergence of vernal pools each year. Though the ephemeral nature of vernal pools makes them a safe place for fairy shrimp to live without fish predators, surviving in such impermanent conditions is no small task. Fortunately, fairy shrimp are well adapted to do just that.
Once their eggs hatch, fairy shrimp have relatively short life cycles, only about a few weeks, allowing them to age and usually reproduce within the short window provided by the pool. In the case that the vernal pool dries up too quickly for the fairy shrimp to reproduce, these clever crustaceans have a backup strategy. Each spring, only a segment of the fairy shrimp eggs that had been laid the previous year will hatch, leaving the rest to remain dormant for potentially several years. That means that the fairy shrimp population can continue to survive, even if the pool doesn’t fill with water one year.
The presence of fairy shrimp is a sign of a healthy ecosystem, as it is considered an indicator species to confirm the presence of a vernal pool; and is exciting to behold if you are lucky enough to witness it.
Spotted salamanders are another species that use vernal pools. Photo courtesy Michigan Natural Features Inventory.
As a lead partner of the Michigan Vernal Pools Partnership, the Michigan Nature Association is committed to protecting vernal pools for all of the species that use them at a number of our more than 180 Nature Sanctuaries throughout Michigan.
