Species Spotlight: Fingernail Clam

by Emma Kull, MNA Communications Intern

Vernal pools are home to several hundreds of different species, including some fan favorites like the spotted salamander and the wood frog. Not all of these pool dwelling creatures are quite as well known–or as easy to identify–as the amphibian ones. One in particular, known as the fingernail clam, is so small that it is easy to miss at first glance. However, if you look a little closer at the pool floor, you’ll find thousands of them!

Photo by Leo Kenney

The fingernail clam is a lesser known, yet tremendously fascinating, inhabitant of the vernal pool wetland. There are many different species of fingernail clams, but the differences are so minute that it takes a serious clam expert to tell them apart. They are aptly named for their similarity in size to a pinky fingernail, with the largest of the species measuring at no more than a half an inch. Fingernail clams are bivalves, meaning their body is protected by two shells hinged together. They thrive in vernal pools, which can have calcium rich bedrock that provides optimal conditions for building strong shells. They have one foot which they use to navigate their surroundings as they feed on the pool’s algae and debris. 

Interestingly enough, fingernail clams can also utilize their singular but mighty foot to survive the vernal pool’s dry season by burrowing up to 8 inches into the moist soil. Other times, these clams will avoid the drying all together by hitching a ride on the toes of a salamander who carries the clam to safety by traveling to a new pool. Some fingernail clams might even clamp down on the feathers of a nearby bird, another suitable shuttle to a different pool. 

Fingernail clams only live for about one to two years, during which they reproduce several times. The self-fertilizing clams store their eggs in a specialized compartment in their gills until each tiny offspring is fully formed and released. The fingernail clam offspring are so large–up to one-third of the adult clam size–that there is simply not enough room for all of them. This leads to a competition for nutrients that is generally won by the older and larger young clams. The winners complete their development and are released into the world to begin their own delightful journey as a fingernail clam.

Bioluminescent Wonders in Michigan

by Emma Kull, MNA Communications Intern

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!

Interacting Safely with Michigan Wildlife

by Jayli Husband, MNA Communications Intern

Michigan is filled with many interesting landscapes such as lakes, forests, marshes, prairies, as well as a popular destination for sand dunes and beaches. With this diversity of natural areas to explore, there are many different species that can be spotted throughout Michigan. With spring in full bloom throughout the state, it is important to be conscious of the native wildlife that may soon be emerging within our forests and neighborhoods and how to properly interact with them. Each spring, there are a number of wildlife encounters throughout Michigan that should be taken with caution.

As temperatures rise, reptiles such as snakes will become more prevalent because they hibernate during the cooler months. After a snake has been clearly seen, it is important to keep a safe distance so that the snake does not feel threatened, this way, they will not react. Snakes will most often avoid humans, in fact, 17 of 18 Michigan snake species are harmless to people. However, if you happen to encounter the Eastern massasauga rattlesnake (Michigan’s only venomous snake), it is best to back away, and if it is staying in a community setting such as a park or backyard have it removed by a professional.

Eastern Massasauga Rattlesnake photo by Zach Pacana.

Unfortunately, the Eastern Massasauga Rattlesnake is now a threatened species because of the loss of habitat, thus, it is important to report any sightings to help conservation and DNR tracking efforts in Michigan. Snakes are very important in their ecosystem; they maintain balance in by eating pests such as mice and rats, and are also important prey for hawks, and other larger carnivores.

In addition to reptiles and amphibians popping back up, coyotes are also a common sight in the spring throughout Michigan. Coyotes can be spotted throughout the year, but it is important to know how to handle monitoring them due to increased activity during mating season. Like many animals, coyotes tend to avoid humans, but it is important to keep watch on small pets and make sure that they are supervised when outdoors if a coyote is spotted nearby. Additionally, coyotes have a great sense of smell, so it is helpful to keep food or smelly garbage contained when it is placed outdoors. To prevent a coyote from moving closer, they can often be deterred by scaring them through loud noises and aggressive hand waving. Coyotes are important for ecosystems as well because they are a keystone species. As a keystone species, coyotes help control the populations of prey species such as rabbits, rodents, deer, snakes, and many more animals which regulates the ecosystem.

Similarly, if a black bear is nearby, it is best to move and give the bear space or scare it off by making loud noises and looking as big as possible. Additionally, according to the Michigan Department of Natural Resources (MIDNR), people should follow the S.M.A.R.T. guidelines with black bears:

  • Stand your ground
  • Make loud noises
    • Always provide a clear escape route for the bear
    • Rarely do bears attack, but fight back if they do
    • Treat bears with respect and observe from a distance.
A black bear with several cubs. Photo by Thomas Wiensch

Black bears are the only bear species that reside in Michigan and only roam in hardwood and conifer forests. Overall, they tend to avoid humans like most animals, but it is best to take caution. Like snakes, bears also appear in the warmer months due to hibernation during cooler months. Bears also play an important role in the environment; like coyotes, bears help maintain the population of their prey including deer, elk, insects, and plants. Uniquely, because bears eat lots of berries, their scat turns into the perfect fertilizer for plants and bushes!

Any direct encounter with these animals are pretty rare. Keep in mind that biting insects such as ticks and mosquitoes pose a more serious threat when out and about this summer. Take common sense precautions with long pants, long sleeves, and repellant while enjoying any lucky wildlife sightings.

It is so important to maintain healthy relationships our wildlife because each animal helps maintain balance in the ecosystem. You can report wildlife sightings to the MIDNR using the Eyes in the Field website, where you can select a category and report your observation. And you can help protect natural areas for all of Michigan’s many species by supporting the Michigan Nature Association.

National Endangered Species Day 2021

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 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!