Tag Archives: Spring Peeper

Cranberry Lake Park: Have Hope! Sure but Subtle Signs of Spring!

The solstice has passed; the days and nights get equal time. But when I’m shivering, my fingers and ears go numb in a stiff  wind, I struggle to hold on to the idea that we’re heading into spring. Until, that is, I head into the parks.

Blog by Cam Mannino

In mid-March,  water birds began splashing down in Cranberry Lake, finding any narrow stretch of open water within the ice sheet. They floated and fed – until one glorious morning, the whole lake turned liquid and bright blue! Migrating flocks honked, chattered and wheeled overhead. Some stopped to rest and feed before heading further north; others explored nesting sites. Our year ’round residents tuned up their spring songs. Territories must be established! Potential mates must be impressed! Best of all, the tiny frogs thawed after their frozen winter state – and now they are  singing! Can genuine spring, with its fulsome birdsong and burgeoning buds be far behind? I think not!

Water Birds Arrive Early, Despite the Ice – and the Muskrats Emerge, too!

It always impresses me that some of the first migrators to arrive in early spring are the water birds! They float, seemingly content, in the icy cracks that form as the sun begins to work on the frozen lake surface. Their cold water strategies involve body fat, oiled feathers, down insulation, and a circulation system which allows cool blood coming up from their feet to pass close to  warm blood traveling down, warming it as it returns to the heart. Below a group of Common Mergansers – black-headed males and brown-headed females –  glided along a thin channel of water on the far side of Cranberry Lake’s iced-over surface.

Common Mergansers – black-headed males, brown-headed females – find a small slit of open water at Cranberry Lake early in March.

Off in the distance, the Wednesday birders spotted the hunched silhouette of a Muskrat (Ondatra zibethicus) perched on the edge of the ice as a goose floated nearby. It slipped in and out of the water, hungry no doubt for food but also for a meager scrap of sunlight after living under the ice all winter!

Two sunny but cold days later, the ice had disappeared and the lake was bright blue and busy with migrating ducks and geese. Two Bufflehead (Bucephala albeola) and a group of Ring-necked Ducks (Aythya collaris)black-and-white males and brown females –   dove and surfaced as they foraged near a Canada Goose (Branta canadensis).

A group of Ring-necked Ducks and two Bufflehead dove and rose next to a Canada Goose as they rested and foraged in the lake.

I got a bit closer to a Bufflehead by checking from the opposite side of the lake. This lone male rocked along on the surface, bobbing under to feed every few minutes. Cornell Lab of Ornithology says Bufflehead accomplish this dive  by compressing their feathers to drive out the air and then pitching forward. A few seconds later, they pop to the surface like a cork and float on.

The Bufflehead dives underwater by pitching forward with its feathers compressed to squeeze out the air, making it less buoyant and able to submerge.

And that same cold morning, what I think was a large muskrat came steaming across the pond toward the eastern side. At the time, I thought this bustling swimmer was a Beaver (Castor canadensis), since there is a large beaver lodge on the western side of the lake. But I’m just not sure of that, so I’m sticking with it being a large muskrat. In the water, its tail looked wide enough to be a beaver, but as it approached the shore, it just didn’t seem to be big enough to be a beaver, unless it was a yearling. And beavers tend to swim with only their heads out of the water. In any case, nice to see this furry fellow plying the pond in the sunshine. What do you think? Big muskrat or young beaver?

The width of this swimmer’s tail made me think this was a beaver, but I think now it was a large muskrat.
From this nearing shore photo, it appears I’ve seen a large muskrat, rather than a small beaver.

Hearing the ancient bugle of the Sandhill Crane (Antigone canadensis), I quickly looked up to see two in the distance, flying into the far end of the lake.  Aren’t we lucky that they breed in our wetlands?

A pair of Sandhill Cranes fly in to check out the edge of Cranberry Lake as a possible breeding ground.

 Spring Songs Signal the Beginning of the Mating Season

As I approached the park one icy afternoon, bright spring music reached my ear – Western Chorus Frogs. These tiny frogs (Pseudacris triseriata – about 1.5 inches long!) are daytime relatives of the nocturnal Spring Peepers (Pseudacris crucifer). They spent the winter frozen solid, no heartbeat, no brain activity, but protected by an anti-freeze of sorts that keeps their tissues from breaking down. Pretty amazing! They thaw out and start singing as the days lengthen. The first afternoon I scanned a wetland trying to see these tiny creatures that seemed to be singing right at my feet, but I could not spot one! So on a second try a few days later, I found a log to sit on near the wetland in the trees just east of the parking lot. After about 20 minutes with my binoculars, I finally spotted two (of the hundreds that were probably there!), the sacks beneath their chins bulging, as they tried to impress a female with their piercing calls. Have a look and a listen!

Two tiny Chorus Frogs with bulging necks sing to attract a mate in the shallow water of a wetland.

A male Northern Cardinal (Cardinalis cardinalis) sang from the tree tops in the eastern meadow, turning every few minutes to send his territory call in a new direction. He’s a bit faint on the recording below, so you might need to turn your volume up! I got a bit closer to another male in a bush near the parking lot later on. He was doing “call and response” with another cardinal hidden in the trees nearby.

And of course, the American Robins (Turdus migratorius) that went south to Ohio and Kentucky returned as well, joining the hardy ones that spent the winter here.

One of many Robins that have returned from Ohio and Kentucky to breed here in the summer.

His spring call is also a bit soft.  And he makes a longish pause before his second “tit whoo” call.

Woodpeckers, of course, use drumming to establish territories, rather than singing.  Both male and female Downy Woodpeckers (Picoides pubescens) attract mates and protect territories with drumming. You can hear their typical drum roll in this Cornell Lab recording which was put to use by the little female Downy below.

I get a huge kick out of hearing flocks of American Goldfinches (Spinus tristis) chirp in the shrubs and small trees. To my ear, they are the only bird that actually says “tweet, tweet, tweet!”  Have a listen at this link and see if you agree! The males are currently molting into their bright yellow summer outfits.

Groups of American Goldfinches are singing their “tweet, tweet” calls in Cranberry Lake Park right now.

On a bird walk one Wednesday, we heard the far distant, insistent drumming of a Pileated Woodpecker (Dryocopus pileatus). Mark, one of the great spotters in the bird group, finally located it with binoculars on a very distant tree, and suddenly its mate (we assumed) dove across the trail far ahead of us before slipping up and away between the trees. No chance for a photo.  But here’s an incredible closeup by talented photographer Monica Krancevic at iNaturalist.org.

Pileated Woodpecker by Monica Krancevic (CC BY-NC) at iNaturalist.org

The First Blooms and Some Sturdy Ferns Wait Patiently

The lovely red blossoms of the Silver Maple (Acer saccharinum) brighten gray days in early spring. They emerge on bare branches before the leaves and are pollinated by the wind before butterflies or other insects emerge and start to pollinate. Those big clusters of scarlet florets are a great food source for hungry squirrels in the spring, when food is scarce, since nuts and seeds are either already eaten or beginning to crack open and sprout.  Last week, I found these male (staminate) clusters fallen from the treetops onto the exposed roots of a large silver maple. I love how the red at the edge of the root echoes the red of the flowers.

The scarlet blossoms of a silver maple are echoed in the root of the tree itself.

Take a closer look at this cluster of florets, some still closed, others waving stamens that have already shed their pollen to wind.  Once pollinated, the female florets will produce winged fruits, called samaras.

A closeup of a cluster of male florets, some closed, some with their stamens already emptied of pollen.

Nearby on the trail to the lake, some sturdy ferns survived the winter with fertile fronds intact.  The brown beads below are the sporangia on the fertile fronds of the Sensitive Fern (Onoclea sensibilis) that carry the spores for this year’s crop of new plants. On the right, are the vegetative fronds that provide sugars through photosynthesis in the summer months.

And the feathery ones below left are the fertile fronds of Ostrich Fern (Matteuccia struthiopteris) whose spores will be released and carried by the wind in the spring. Their vegetative fronds on the right stood tall and bright green, taking advantage of the moist soil and spotty sunshine in the forest.

Spring Just Peeks Out…Here and There

A pair of Canada Geese rest in the quiet refuge of a shaded wetland

Behind a scrim of small trees on the way to the lake, I spotted these two Canada Geese floating serenely in a secluded wetland, away from the noisy flocks gathering on the lake. They reminded me that, at this time of year, spring has to be sought out. It appears and disappears. One day the lake is iced over, a few days later it’s rippling and blue and then the snow falls again. On some days, spring isn’t easily seen – just a few red blossom clusters floating in a vernal pool  or scattered on the lifeless grass. Sometimes spring can only be heard and not seen. Frogs as tiny as your thumb sing unseen one day and the next, perch on a bit of floating grass, their throats bulging with amorous sound. Flocks twitter or honk high in a cold blue sky or male birds rehearse the first tentative versions of their mating songs. Woodpeckers tap out a seductive rhythm on the bark of trees.

The Eastern Meadow at Cranberry Lake doesn’t look very spring-like yet – but the clues are there.

Early spring isn’t flamboyant and colorful, like it will be in a few weeks. It’s hesitant, waiting to be found and enjoyed if we can only slow down enough. If we watch, we’ll see it peeking through the alternating rain or snowfall, cracking and opening in thawing ponds or hear it whistling, chirping, trilling from inside the brush or high in the treetops. So I hope you have time to delight in these  subtle hints of early spring as they unfold. It won’t be long now…

Footnote: My sources for information, besides Oakland Township's Stewardship Manager Ben VanderWeide, are as follows: Caterpillars of Eastern North America by David L. Wagner; inaturalist.org;Allaboutbirds.org, the website of the Cornell Ornithology Lab at Cornell University; Wikipedia; Herbarium of the University of Michigan at michiganflora.net; various Michigan Field Guides by Stan Tekiela;Butterflies of Michigan Field Guide by Jaret C. Daniels,  and others as cited in the text.

Photo of the Week: Early Spring Frogs Thaw Out and Start Singing

 

This Chorus Frog in mid-cheep is thawed and singing, but spent the winter frozen.

Early spring frogs have resurrected and their music fills the air! When the first ice of last winter formed on these little amphibians, they reacted by producing a glucose anti-freeze. According to Bernd Heinrich’s book, Winter World, “In about fifteen hours, the frog is frozen solid except for the insides of its cells.  Its heart stops. No more blood flows. It no longer breathes. By most definitions, it is dead.” But as the weather warms, chorus frogs, wood frogs, and spring peepers thaw out and begin to serenade their mates in your local vernal pool or wetland. Spring Peepers (Pseudacris crucifer) are nocturnal, but you can hear Chorus Frogs (genus Pseudacris) and Wood Frogs (Rana sylvatica) singing all day. Enjoy nature’s spring miracle!

Enjoying an Evening of Turtles, Salamanders, Frogs and, oh yeah, a Rattlesnake!

Last Thursday, Ben VanderWeide, our township stewardship manager, hosted a well-attended event on rare/endangered “herps” (Herpetofauna), that is, amphibians and reptiles.

Blog and photos by Cam Mannino
Blog and photos by
Cam Mannino

At this time of year, talking about snakes, turtles, salamanders and frogs may seem a bit odd to you.  Actually though,  the Herpetology expert and presenter, David Mifsud of Herpetological Resource Management (HRM), told us that he sees Spring Peepers, Eastern Garter Snakes and Red-backed Salamanders moving around in Michigan winters when temperatures warm up as they have lately.    So for starters, here are three that he says we might look for during this winter thaw:

 

Garter snake closeup GC
Eastern Garter Snakes (Thamnophis sirtalis sirtalis) may be moving on warm winter days.
red-backed-salamander-1
You could see a Red-backed Salamander (Plethodon cinereus) in a vernal pool created by snow melt.
Spring Peeper largest size
Spring Peepers (Pseudacris crucifer) can occasionally be heard/seen on a warm winter day.

And even if you don’t see one of these herps “in person” this winter, it’s just pleasant to think about springtime creatures in the dead of winter, right?  So here’s a brief trip through some of the important and lively information that David shared with about 30 of us last Thursday night.

Note:  Because some of these creatures are rare, some of the photos this week are courtesy of photographers at iNaturalist.org.  Please check the captions for names of these gifted people and many thanks to Creative Commons, iNaturalist and these photographers for sharing their work!

How Important are Amphibians and Reptiles?  Let Me Count the Ways…

  • Canaries in the coal mine. Amphibians and reptiles accumulate toxins and other contaminates in their bodies and most live both in water and on land.  So they are effective gauges (bio-indicators) of what’s getting into both environments.
  • Many eat invasive species.  For example,  the very homely Mudpuppy (Necturus maculosus), an aquatic salamander, favors eating invasive Zebra Mussels (Dreissena polymorpha) and  invasive Brown Gobies (Neogobius melanostomus), both huge problems in the Great Lakes. I grant you  this much-maligned aquatic salamander is not pretty. But it’s eating these invasive species, crayfish, worms,  and insect larvae! There’s no evidence that they reduce game fish populations (see Harding 1997). So please!  Return them with care to the water if you catch them on your hooks winter or summer.
original
Mudpuppies eat invasive species not game fish. Photo by Marcus Rosten CC-BY. I lightened and cropped slightly.
  • Predator and Prey. Herps can be both predator and prey, meaning they’re important in nature’s food web.  For example, dragonflies, like the Widow Skimmer (Libellula luctuosa) on the left below,  lay eggs in vernal pools.  The  nymphs that hatch feed on the eggs of salamanders who deposit their eggs on sticks in vernal pools, as seen in the center photo.  But when the Tiger Salamander (Ambystoma tigrinum) on the right – an inhabitant mostly of western and southern Michigan –  reaches adulthood,  it in turn eats dragonflies.  This kind of food cycle helps keep a healthy balance between predator and prey in the ecosystem and builds the ladder system of the food web.
  • Our natural heritage. And of course, these creatures deserve our care because they are native to the habitats which are our natural heritage. And just as we preserve historic homes, we need to preserve the habitats for plants and animals that share our natural inheritance.
  • Just because. These beautiful creatures deserve a place to call home too!

And the Prognosis for Michigan Herps?  Uh, Not So Good…

Unfortunately, in Michigan and the Great Lakes Region, more than half of our species of amphibians and reptiles are declining. Why?

  • Amphibians and reptiles spend time on land and in the water. So those pollutants and contaminants that they accumulate, making them bio-indicators, can also kill them. Plastic beads in beauty products, pesticides from lawns and agriculture, hormones from our medicines in waste water, and agricultural run-off can affect these creatures.
  • Many reptiles have to live a long time in order to mature and reproduce.  The Blanding’s Turtle (Emydoidea blandingii), found in our township,  is listed as a Species of Special Concern in Michigan. It takes up to 20 years for these yellow-chinned turtles to mature enough to produce young and they can live up to 90 years! This one on a road near Draper Twin Lake Park is demonstrating one of the hazards – habitat loss or disruption.  In this case, a road cut through its habitat. If you see a turtle on the road and can safely do so, be sure to move it gently in the direction it was going or it will turn head right back the way it came. Turtles are very focused on getting to and from their breeding grounds!

    Blandings Turtle near Draper
    A Blanding’s Turtle has to survive up to 20 years before it produces young!
  • Creatures with long lives like turtles especially need connected habitat corridors since they require both water and dry land, where they lay their eggs. Here a Common Snapping Turtle (Chelydra serpentina) is laying her eggs high on a sunny slope in Bear Creek before she returns to the pond. She demonstrates a common natural hazard. A female Snapper has a strong scent from living in marshes so it’s easy for predators – like foxes, coyotes, or raccoons – to track down her nest of eggs. And the mounds of earth she leaves behind are a big clue too!
snapper laying eggs
A Snapping Turtle leaves a strong marsh scent on her trail that lead predators, like raccoons, to her nest of eggs.
  • As cute, and as pesky,  as raccoons can be, they are serious predators of amphibians and reptiles and over-populated in some parks. Their numbers are often higher in urban areas than they would be naturally because they are “subsidized” by the food we provide unwittingly, such as our trash and the dog food we leave outside. After racoons leave the feast in your backyard, they return to a local natural area to snack on amphibian and reptile eggs, often causing over 90% nest failure. To keep park environments in balance between predators and prey, please remove food sources from around your home, and don’t transport trapped raccoons or other animals to our parks! 

 

raccoon in hole
Raccoons are efficient predators of “herp” eggs and young. So please don’t transport yours to the parks or we’ll have too many! This one peeked from a tree at Bear Creek.

Of course,  birds and other creatures prey on amphibians and reptiles as well.  This Cooper’s Hawk (Accipiter cooperii) is heading for quite a feast!

cr cooper's hawk with snake
A Cooper’s Hawk prepares to dine on a snake.
  • Unfortunately, salamanders and turtles are sometimes poached from the wild for pets, both by wildlife traffickers and uninformed parents and children. This has had a devastating effect, for instance,  on the very cute and tiny Spotted Turtle (Clemmys guttata) who’s only 3-5 inches long! And the same thing has happened to Box Turtles (Terrapene carolina) and even Common Snappers, which are sold overseas as well as domestically for supposed “medicinal” purposes.
spotted-turtle-cc-no-my-photo
Photo of the tiny Spotted Turtle by Todd Pierson (CC BY-NC-SA) whose numbers have declined due to treating them as pets.

The Leopard Frog (Rana pipiens), which appears in our parks, is also a Species of Special Concern in Michigan due to its declining numbers. This lovely frog with its emerald body and oval spots has unfortunately been poorly studied. So researchers still need to find the reasons for its distress.

leopard frog
The Leopard Frog’s numbers are declining and no one yet knows exactly why.

OK, but what about that Michigan rattlesnake???

emr_andrewhoffman2008_cc-by-nc-nd-3
Photo by Andrew Hoffman CC BY-NA-ND 4.0. No changes were made to the photo.

Most of us have heard of, but never seen, Michigan’s most venomous snake, the Eastern Massasauga Rattlesnake (Sistrurus catenatus catenatus) (a couple other snakes have weak venom that only causes irritation). This very shy, low-key snake only grows to about 2 feet long. According to Michigan DNR, it has one set of rattles at birth and develops more as it sheds its skin several times each year.  Its head is triangular like most rattlesnakes, though it is the smallest and least venomous rattler in the U.S.  Look also for a vertical eye slit and saddle-shaped spots.

The likelihood of you being bothered by this snake is low.  In 2016 it was listed as a Federally Threatened Species, which means its numbers are becoming drastically low.  And these snakes just want to avoid you. David reports having searched for this snake with a tracking device and after hearing a loud “beep” from his device, found it under the grass between his feet!  As he moved the grass aside, the snake silently slid over his shoe and away. That’s a conflict-avoiding snake! And a herpetologist with nerves of steel, I might add.

So if you do get to see one, consider yourself lucky. Don’t hurt or handle these docile snakes, since folks most often get bitten when harassing a snake that just wants to get away. Many bites are “dry,” meaning no venom. It takes lots of energy for the snake to produce the venom, and it doesn’t want to waste it! But if you get any kind of bite from this snake, see a doctor right away. Luckily, Dave informed us that no one in the US has died from such a bite in 100 years.

In spring, when these snakes are most active, they’re seen near wetlands, but they are likely to move to drier, upland areas in the summer. While they been seen recently at Stony Creek Metro Park in our area, we have no recent sighting in our township parks. Let us know if you see one!

Massasaugas overwinter for up to six months under logs, in small animal burrows and often in the “chimneys” created by crayfish, like this one.

A recently refreshed Crayfish hole among the detritus
A recently refreshed crayfish hole can hold many creatures over the winter, occasionally including Massasauga rattlesnakes.

Evidently, these burrows fill with ground water which maintains a more constant temperature in the winter than above ground – and that’s what important to an animal that can’t control its body temperature internally.  What’s amazing is that they often share these chimneys with other small creatures during the winter when all of them are in hibernation mode.  A kind of winter “condo” as David described it.  Imagine that!

Befriending Our Local Amphibians and Reptiles

Five turtles line up on a log at Bear Creek Nature Park.
The “Von Trapp Family”  Painted Turtles line up on a log at Bear Creek Nature Park.

Our parks are great places to see all kinds of “herps.”  Snappers and painted turtles cruise Bear Creek’s ponds and marshes.  Our wetlands in every park fill with a chorus of frog song every spring.  Snakes bask in sunny spots and quickly disappear into tall grass.  And in moist woodland uplands, salamanders emerge on the first warm night to make their way to vernal pools to mate and lay their eggs.  We need to care for these interesting creatures and their habitats  to be sure that they still thrive in our world when our children or grandchildren go looking for them.

Footnote:  My sources for information, besides Oakland Township's Stewardship Manager Ben VanderWeide, are as follows: 
Harding, James H. (1997) Amphibians and Reptiles of the Great Lakes Region. iNaturalist.org for periodic photos;Ritland, D. B., & Brower, L. P. (1991); Stokes Nature Guides: A Guide to Bird Behavior Volumes 1-3, Allaboutbirds.org, the website of the Cornell Ornithology Lab at Cornell University; Wikipedia; http://www.butterfliesandmoths.org; Herbarium of the University of Michigan at michiganflora.net; various Michigan Field Guides by Stan Tekiela; Butterflies of Michigan Field Guide by Jaret C. Daniels; University of Wisconsin's Bug Lady at www4.uwm.edu/fieldstation/naturalhistory/bugoftheweek/ for insect info; http://www.migrationresearch.org/mbo/id/rbgr.html for migration info; invaluable wildflower identification from local expert, Maryann Whitman and the website www.illinoiswildflowers.info; experienced birder Ruth Glass, bird walk leader at Stoney Creek Metro Park for bird identification; Birds of North America Online; Audubon.org; Nature in Winter by Donald Stokes, Trees in My Forest by Bernd Heinrich, Winter World by Bernd Heinrich, Savannah River Ecology Lab (Univ of Georgia); Tortoise Trust website www.tortoisetrust.org;  An Orchard Invisible: A Natural History of Seeds by Jonathan Silvertown; The Ecology of Plants by Gurevitch, Scheiner and Fox; other sites as cited in the text.

THIS WEEK AT BEAR CREEK: Icy Trails and…Frozen Frogs?

Marsh colors 2winter2015

Cam in red winter coat BC
Blog post and photos by Cam Mannino

The red blush of Red Osier Dogwoods (Cornus sericea) at the edges of Bear Creek’s wetlands provides very welcome color in the brown, gray and white world of a Michigan winter.   The last week of the year, tiny beads of ice fell from the sky for hours,  covering the trails and making for tricky walking.  But at least you’ll never lose your way!  Though the fields are mottled brown and white, the icy trails shine bright white in the landscape.  And deer trails through the thickets are readily apparent, too.

Bare branches and ice make it possible in the winter to really see the southernmost pond in the park near Snell Road.  It’s hidden by surrounding foliage in the summer which probably is why so many warblers and other migrants spent time there in the spring and fall.

Hidden pond at BC
Bear Creek’s southernmost pond near Snell Road is most visible in the winter.

A Muskrat (Ondatra zibethicus) at the marsh had evidently walked across the icy slush either to or from its feeding push-up before the slush turned to ice.  Perhaps you can just make out its frozen footprints in this photo.

muskrat trail near push up marsh
A muskrat left a trail in the icy slush that led to or from its feeding push-up in the marsh and across the ice.

A group of hardy American Tree Sparrows (Spizella arborea) repeatedly darted from low bushes down onto the reeds of the marsh.  What could they be finding to eat?  Perhaps seeds, perhaps some frozen insects that mistakenly hatched in the unseasonably warm weather before the ice?  No doubt skills these little birds developed on the tundra during the summer make finding food here seem like fledgling’s play!  Aren’t they nicely camouflaged for this grey and brown time of year?

Tree sparrow in the marsh
A Tree Sparrow finding food in the frozen marsh.

Mallards (Anas platyrhynchos), of course, found a small area of open water where they could feed.  Most of their compatriots have moved south a bit, but some still probe the depths at the Center Pond and the marsh.

Mallard in Center Pond2
Mallards find a small area of open water.

Ice takes so many beautiful forms this time of year.  Forming on the Playground Pond , it looked as though it were embossed on some elegant blue/gray satin.

ice on playground pond
Ice forming patterns on the Playground Pond

On grass stems, heavy frost looked granular and spiky.

Frost on grass stems
Heavy frost on grass stems

And doesn’t heavy frost also do a lovely job of tracing the shape of this Queen Anne’s Lace?

Iced queen anne's lace
Heavy frost outlining a Queen Anne’s Lace blossom

Winter is a time of ice and stark shadows so be prepared for more photos of both as the season moves on!

So with all this ice, how do frogs survive the winter?  No, not deep in the mud…

Frog in duckweed
A green frog in summer

It’s true that some frogs, like the ubiquitous Green Frogs (Rana clamitans) of the Center Pond, are spending the winter under the pond ice.

Like the turtles, their metabolism slows drastically to preserve their oxygen during hibernation.  Unlike turtles, though, they can’t bury themselves in the mud because they need to absorb oxygen from the water through their skin.  So they may have a light coating of mud or simply lay inert on the pond bottom waiting for spring. At times, they may even swim slowly through the water.  TadpoleIt can take 2-3 years for a Green Frog tadpole to develop into a frog, so some of their tadpoles are below the ice as well and are reportedly a bit more mobile than the adult frogs.

The striking Leopard Frog, less common in Bear Creek and across the state, also hibernates below the ice.

leopard frog
The Northern Leopard Frog also hibernates on the bottom of ponds at Bear Creek.
Frogs that Freeze!

Incredibly, the smallest frogs of early spring actually freeze in the winter and thaw out in the spring!

The Wood Frog (Rana sylvatica), for example, finds a crevice in wood or a rock or simply under leaves, and waits.

Wood frog
A Wood Frog burrows into leaves for the winter, freezes, stops breathing, no heartbeat – and then thaws in the spring!

According to biologist Bernd Heinrich in his book, Winter World, when ice begins to form on any part of its small body, an alarm reaction makes a Wood Frog release adrenaline which signals the glycogen in its liver to turn to glucose which functions like anti-freeze.  “In about fifteen hours, the frog is frozen solid except for the insides of its cells.  Its heart stops.  No more blood flows.  It no longer breathes.  By most definitions, it is dead.” But they thaw in the spring!  As Scientific American describes it, “…when the hibernaculum [the place where an animal hibernates] warms up above freezing, the frog’s frozen portions will thaw, and its heart and lungs resume activity–there really is such a thing as the living dead!”  How amazing is that, eh???  Spring Peepers (Pseudacris crucifer) and Chorus Frogs (genus Pseudacris) can do this as well.

frog and reflections2
A Wood Frog in a vernal pool near Gunn Road

These small frogs live mostly on land.  Once they thaw, however, they quickly go to vernal pools to breed.  Because vernal pools are created from snow and ice melt, these frogs do better after a snowy winter.  Their frozen hibernation in shallow places allows them to thaw quickly in the early spring and  mate in these temporary pools, safe from predators like fish or turtles who need permanent ponds.  The tadpoles of these early spring species become frogs much more quickly than the Green Frog’s do, in a matter of weeks or months,  since the vernal pools, like the one near Gunn Road, shrink or disappear as summer comes on.

So nature does it again!  As we tread gingerly along the icy paths of Bear Creek, we can imagine Green Frogs sprawled along the bottom of the pond and tiny spring frogs frozen under leaves or in tree bark waiting for an almost literal rebirth in the spring.  We humans use our complex brains and fire fueled by ancient plants  to survive an icy winter, while  little frogs use massive amounts of homemade antifreeze.  Ice requires a lot of different adaptations for survival and over thousands of years, nature, as always, finds a way.

*Footnote:  As well as Oakland Township Stewardship Manager, Dr. Ben VanderWeide, my sources for information are as follows: Ritland, D. B., & Brower, L. P. (1991);Stokes Nature Guides:  A Guide to Bird Behavior Volumes 1-3, Allaboutbirds.org, the website of the Cornell Ornithology Lab at Cornell University; Wikipedia; http://www.butterfliesandmoths.org; Herbarium of the University of Michigan at michiganflora.net; various Michigan Field Guides by Stan Tekiela; Butterflies of Michigan Field Guide by Jaret C. Daniels; University of Wisconsin's Bug Lady at www4.uwm.edu/fieldstation/naturalhistory/bugoftheweek/ for insect info http://www.migrationresearch.org/mbo/id/rbgr.html for migration info; invaluable wildflower identification from local expert, Maryann Whitman; experienced birder Ruth Glass, bird walk leader at Stoney Creek Metro Park for bird identification; Birds of North America Online; Audubon.org, Nature in Winter by Donald Stokes, Trees in My Forest by Bernd Heinrich, Winter World by Bernd Heinrich, Savannah River Ecology Lab (Univ of Georgia), Tortoise Trust website www.tortoisetrust.org and other sites as cited in the text.