EASTHAMPTON — Frogs. Within the next few weeks the earliest of them will start calling — spring peepers, whose high, eager cries have always reminded me of the belling of a pack of faerie hunting hounds.
An age-old symbol of transformation, frogs couldn’t be a more fitting sign of spring. In growing from tadpole to frog, these weird beings are the largest animals on earth to experience such complete metamorphosis from larval to adult form.
Their yearly chorus heralds the startling changes soon to overtake the landscape — buds burgeoning to silvery green leaflets and then to shading leaf; flowers unfurling extravagant banners; birds knitting finely-crafted nests. What the frog does the whole world imitates.
As Charlotte Sleigh points out in her remarkable book “Frog,” these slimy beasts, frog-princes-to-be, are liminal animals, creatures of the in-between. Emerging at dusk, they live between land and water, breathing through their skin, hibernating through winter. Sleigh’s book is part of a series of animal books by Reaktion Books in London, and I’ve been reading its generous romp through frog biology, history, mythology and cultural significance.
In fact, lately I’ve been on a bit of a frog kick (forgive the pun). This month, I attended a training workshop at Mass Audubon’s Arcadia Wildlife Sanctuary for FrogWatch USA, a citizen science program run by the Association of Zoos and Aquariums.
Through FrogWatch, volunteers collect data on frogs living near their homes, then submit their findings so scientists can learn more about frogs’ distribution, behavior, and abundance over time.
Ten species of frog and toad call Massachusetts home. Before the workshop, I thought I was a pretty good frog-listener — I already knew the spring peeper, the wood, green, leopard, bull, and tree frogs, and the American toad.
But odd little denizens like the spadefoot toad — whose call to my ear imitates a video-game laser gun with a dying battery — were new to me.
So was the Fowler’s toad, which emits a harrowing screech, at once horror movie and squeaky toy — “waaaaaaahhhhhh!” — sounding, as Brittany Gutermuth put it, “like someone squeezing a baby.” Gutermuth is the coordinator for the Connecticut River Valley chapter of FrogWatch.
Learning about frogs can help volunteers connect to and understand their local environment. Most importantly, though, scientists seek to monitor these animals because like so many precious parts of our natural world, frogs are under threat.
Globally, one in three species of amphibian is at risk of extinction, a group including frogs, salamanders, and a group of strange worm-like animals called caecilians. Amphibians are particularly vulnerable to environmental stressors for some of the very reasons that make them so fascinating in the first place.
Frogs “are an indicator species in the environment,” says Gutermuth. “We’re really thinking of them as canaries in the coal mine.”
When the environment is unhealthy, frogs are among the first to show the effects. Their wet, permeable skin easily absorbs chemicals like pesticides or industrial chemicals, as do the eggs they lay in clusters or strands in water. Disease and mortality can result.
Frogs require wetlands for breeding, after which many species migrate to drier ground in forests or meadows. They’re therefore highly sensitive to habitat loss or to fragmentation by roads and urban sprawl.
Wetlands enjoy protection from the state. However, formal designation of vernal pools, a type of wetland, is left up to the judgment of individual municipalities, Gutermuth points out. Vernal pools are seasonal ponds that form in forests from snowmelt and rain. Because they’re unconnected to streams and rivers and last just a few months, they lack large predators like fish that could threaten eggs or tadpoles, making them vital to many frog species.
Only vernal pools formally certified as such qualify for state protection, making them vulnerable to development.
Disease outbreaks have also caused mass frog die-offs, particularly the infamous chytrid fungus that has caused extinction of hundreds of species since first detected in Queensland, Australia in 1993. It’s not clear if this infectious disease hitchhiked from one source, or if frogs have always had chytrid but changes in the environment allowed it to become vastly more virulent.
Finally, climate change presents major challenges to frogs, notes Gutermuth, who is also the climate education coordinator at Mass Audubon.
Temperature shifts can disconnect the emergence of tadpoles and froglets from that of their preferred insect prey, leaving the animals hungry. Warmer temperatures can change the gender of developing eggs, creating an imbalance of too many males relative to females or vice versa depending on the species.
Drought and early snowmelt can dry out wetlands or vernal pools. Climate change alters the timing of breeding season and can mess with hibernation.
On a couple unusually warm days this December, for instance, I heard a few confused spring peepers singing out their breeding call as I pedaled my bicycle down the rail trail in Hadley.
Those peepers may manage to dig themselves back into the mud for hibernation, Gutermuth said, but if the warm spell’s too short, they’ll die.
It’s a lot. The threats can feel overwhelming.
But causes for hope persist. Resistance to chytrid fungus, for instance, appears to be growing in frog populations, slowing the rate of mortality.
Through FrogWatch, volunteers can help assure the survival of vernal pools by documenting the presence of obligate vernal-pool breeders. “Wood frogs only breed in vernal pools, so if you hear one giving a breeding call, it’s a vernal pool” and should be protected, says Gutermuth.
And I always think that pure love is a cause for hope. Frogs are beloved worldwide for their cute little faces, their sticky-pad toes, their crazily athletic tongues that can zap out to nab a fly midflight. If we love them hard enough, we possess the power to keep them safe, as in the frantic frog collection and breeding programs launched after the discovery of chytrid that kept many species alive in captivity.
Better still would be changes to our lifestyle and society to protect the broader environment — less chemicals, less fossil-fuel burning, more thoughtful and limited development, less urban sprawl.
Programs like FrogWatch can help by indicating wetland health or helping planners decide whether or how to develop a landscape that supports frogs and toads. The program also helps detect invasive species that may threaten native frogs.
For instance, the Atlantic Coast Leopard Frog has slowly been making its way north. Most recently heard by volunteers in Connecticut, it hasn’t been noticed yet in Massachusetts, but as the climate warms could arrive here any day.
To survey frogs, frogwatchers are asked to attend a training like the recent workshop, then choose a wetland site to visit weekly a half-hour after dusk. Using their ears, not their eyes, the volunteers identify frogs by their calls and decide whether they hear individual calls, a partial chorus, or a full chorus for each species. Data can be uploaded to the FrogWatch USA website.
At the workshop I sat next to Michelle Kofler, a physical therapist who lives in South Deerfield. She and her partner Jon Messeck came to FrogWatch because of their own garden.
“We’ve planted a bunch of native plants in our yard, and we’ve noticed a bunch of frogs — some frog species I wouldn’t have expected, because we live in a dry area,” she said.
She showed off a photograph of a tiny, sleepy-eyed gray tree frog clinging to a milkweed leaf.
Messeck, who used to work for a native plant nursery, said they’ve spotted monarch butterfly caterpillars on the three kinds of milkweed they’ve planted in their garden. Insects attracted by their plants may be part of what makes their yard inviting to frog denizens.
Wood frogs, I think, remain my own favorite. Their low duck-like quack is soft individually, but a full chorus can grow deafening in wet pockets of New England forests by mid-spring.
These little masked bandits have the fascinating ability to freeze solid in winter and still survive. Their cells contain a kind of antifreeze that prevents water from crystallizing inside, meaning that the cells won’t explode once they thaw.
That’s better magic than transforming into a handsome prince, in my book: getting through the frigidity of winter, year after year, to greet another season with eros and song. To heck with a beautiful golden ball; it can stay in the swamp. I’ll take the frogs.
To engage with FrogWatch USA, coordinator Brittany Gutermuth can be contacted via Mass Audubon at the Arcadia Wildlife Sanctuary in Easthampton.