Complete the lyrics: Nothing else matters in the whole wide world when you’re in love with a…
If you said Jersey Girl, then you’d be correct! Coincidentally, that’s also where volunteers and supporters alike gathered last month to show their love for amphibians. Jersey Girl Brewing in Mount Olive, that is.
Two years ago, we partnered with Jersey Girl to host a trivia event to raise awareness for our Amphibian Crossing Project, an initiative that seeks to reduce mortality among populations of frogs and salamanders whose migratory pathways are bisected by roadways. We chose the location based on its proximity to our largest crossing site, Waterloo Road, in the hopes that many of our hardworking volunteers could attend. We had a great turnout and a lot of fun. Following several requests, we decided to bring it back this year for round two.
Participants, including former CWF intern, Nicole Bergen (who helped write and host our first trivia event) pause during answer deliberation to smile for the camera.
Lots of familiar faces were in the crowd at Jersey Girl, including CWF’s Founder, Linda Tesauro, trustees Steve Neumann, Rick Weiman, and Amy Greene, former amphibian crossing leads MacKenzie Hall and Allegra Mitchell, former CWF intern, Morgan Mark, and many new and seasoned volunteers, like Barb and Rick McKee, without whom, this project could not succeed.
We’ve made it to the final “super species” in our “superhero” series though, like in the last post, we’re spotlighting an adaptation that aligns with one of the more notorious residents of Gotham City. Our local frog has all the chill, while this DC villain needs to chill… quite literally, as his sub-zero body temperature must be maintained to ensure his survival. Cryogenics expert, Dr. Victor Fries- better known as Mr. Freeze, had admirable intentions when he began his experimentation with ice. Unfortunately for him, accidental exposure to chemicals altered his physiology, necessitating the use of an air-conditioned suit and spurring a life of crime motivated by tragic desperation. The compound responsible for his transformation is thought by some to be glycerol, which also happens to be the key to the winter survival strategy of our favorite early breeding anuran- the wood frog (Lithobates sylvaticus).
Animals living in temperate climates must find ways to cope with the cold temperatures and reduction of food resources, characteristic of the winter season. Some species deal with winter by not dealing with winter… instead they migrate to milder conditions farther south. This is a path commonly taken by birds. Other animals have adapted to have a large body mass. This reduces their surface area and enables them to hold onto heat more efficiently. As a former moose biologist, I’m happy to give them a quick nod here. Many strategies exist across the natural world to increase the odds of persistence, but we’re here to talk about amphibians and, it’ll probably come as no surprise to you that they aren’t employing either of the aforementioned tactics.
Wood frogs are a vernal pool obligate species; they must have access to these temporary wetlands in order to breed and complete their lifecycle, but they don’t live in them all the time. Therefore, we do refer to them as migratory, but they only cover about ¼ to ½ mile during this annual pilgrimage, so temperature differences are negligible. Most frogs and salamanders in New Jersey endure the colder months by entering brumation- the “cold blooded” equivalent of hibernation. In this state, animals can drop their body temperature and metabolism to conserve energy. Some species burrow and use the ground as insulation. Others brumate in streams and ponds since water cools at a slower rate than air. Wood frogs cover themselves in leaf litter (for camouflage) and spend the winter comfortably as frog-cicles. That’s right- they essentially freeze solid and thaw once air temperatures become favorable again.
Under normal conditions, when a cell freezes, ice crystals form internally. These solids can then expand, which damages organelles and ultimately ruptures cell membranes. This leads to cell death. Compounded by damage incurred in blood vessels and dehydration, this would be a fatal situation for most animals. Wood frogs have found a hack to get around these devastating consequences.
A recently thawed wood frog huddled beneath a leaf. Photo credit: Nikki Griffiths.
As temperatures drop, wood frogs continue to produce urine but cease voiding it. Instead, the urine is concentrated into urea, which floods the frog’s bloodstream. The liver also goes into overdrive, manufacturing vast quantities of glucose, which causes their blood sugar to skyrocket as high as 100x normal levels (a better understanding of how this frog can avoid negative health effects under such conditions could certainly contribute to diabetes research in humans). The urea and glucose create a mixture that acts almost like antifreeze. Once ice crystals begin to form around the blood cells and internal organs, this homemade antifreeze infiltrates, allowing for the retention of water and protecting the frog’s cells from desiccation and explosion. They can maintain this state for up to 8 months.
This brumation strategy earns wood frogs the “northernmost amphibian in the western hemisphere” superlative as they can be found up past Gates of the Arctic National Park in Alaska.
The 2023 Amphibian season has begun! Drive carefully one upcoming rainy nights. Photo credit: Nikki Griffiths.
That’s a wrap on Mr. Freeze and our Super Species! The Amphibian Crossing is now in full swing. If you are going to be driving after sunset along roads that border ponds in the upcoming rains, watch out for migrating frogs and salamanders. Collisions with motor vehicles can decimate local populations rapidly so please slowdown!
CWF intern Connor Zrinko inspects a large tadpole he collected while dipnetting.
At quick glance, Pine Barrens tree frogs (PBTF), with their vivid green backs, deep purple sides, and vibrant yellow thighs, might put folks in mind of Central and South American rainforests. Based on their visage, they could, theoretically, be at home beside red-eyed tree frogs and poison arrow frogs – the poster children of amphibian diversity. They have occupied that spotlight themselves. In fact, in his 1983 Endangered Species series, American pop artist Andy Warhol chose to immortalize the PBTF in silkscreen as the lone representative of herptiles. But these tiny beauties do not favor the tropics. Occurring in three disjunct populations across the eastern United States including the Florida/Alabama panhandle, the Carolinas and, naturally, New Jersey, PBTF are habitat specialists. They reside in seepage bogs where the water is relatively acidic, due to the presiding vegetation. Sadly, as is the case with many animals reliant on very specific landscape features, habitat loss and fragmentation pose a concern for the persistence of this species, which is listed as threatened in New Jersey.
CWF is very excited to be partnering with NJDEP, Division of Watershed Protection and Restoration on a long-term study aimed at better understanding the effect of development on vulnerable species. We will measure abundance, adult health and survival, and larval growth of Pine Barrens tree frogs within a population impacted by encroaching construction to evaluate whether current wetland regulations, including buffer size, are sufficient for species conservation.
A volunteers handles a spotted salamander. Photo by Mackenzie Hall
The Conserve Wildlife Foundation has been partnering with NJ’s Endangered and Nongame Species Program (ENSP) since 2002 for the annual Amphibian Crossing Project. On warm, rainy nights in the early Spring, we work with a fleet of incredible volunteers to hustle amphibians across the road at three key rescue sites. Still groggy from their winter hibernation, roads can be incredibly dangerous for the slow moving frogs and salamanders trying to reach their breeding grounds.
Over the course of this project, we’ve crossed an estimate 14,000 individuals at the Byram Township site alone!
Commenting on last Thursday’s crossing, the first of 2021, Amphibian Crossing Project Coordinator Christine Healy had the following to say:
“We were a little unsure of what to expect, since the temperature was a little on the cold side, but we crossed 1,215 amphibians at Byram Twp., 1,132 at Stillwater, and 963 at Liberty Twp.
I’d call that a success! Really proud of all the volunteers who made it happen.
Conditions look like they could be good toward the end of this week for round two!”
Bruce A. Scruton of The New Jersey Herald recently spoke with Christine to discuss the Amphibian Croosing Project and its storied history.
You can read the profile over on NJHerald.com to learn more about what it takes to help hundreds of our amphibian friends hop and meander across dangerous roadways.
The spotted salamander is one of the key amphibian species which crosses roads on their journey to reproduce every Spring, prompting road closures and volunteer crossing efforts like the Amphibian Crossing Project.
Wild New Jersey Revisited is a monthly series of excerpts from Conserve Wildlife Foundation executive director David Wheeler’s 2011 book Wild New Jersey: Nature Adventures in the Garden State. Today we focus on a springtime migration…of miniature proportions – and one that could be occurring again tonight!
Excerpt from Chapter 22
Wild Nights in Suburbia
It’s not often that I find myself praying for rain on the way out the door. No, when I’m about to spend three-plus hours standing outside on a chilly Sunday evening in March, I usually prefer to stay dry. I’m kind of picky that way.
So if it seems odd that I let out a quick cheer when a few raindrops appear on my windshield as I navigate treacherous backroads in Warren County – well, there’s good reason. Without the rain, there are no salamanders crossing the road. And without salamanders or frogs, the scientists and a truckload of committed volunteers have no reason to be out here in the chilly twilight.
I arrive at the site, and my windshield is dry again. I fear that those lone raindrops were just a big tease. It could be a long night. Somewhere in the distance, a great horned owl hoots. Near the road, a lone spring peeper calls without end like a soapbox preacher. Perhaps he is divining the future for his fellow amphibians, and for us.
After all, this is their migration. We are just here as bouncers, keeping cars and trucks from crashing their party. Tonight, rain is the only question mark. The temperature is in the ideal range, mid- to upper forties. As planned, the night grew dark when the sun went down. (Whew – that’s a relief!) So that’s two out of three needs for the crossing to begin.
All we need is rain. One volunteer checks the Doppler radar weather forecast on his phone every few minutes.
“There’s a system over Lehigh Valley now, but it’s moving our way pretty quickly.”
Another volunteer reminisces about the good old days.
“2002 – that was the best year. We got a torrential downpour.”
A wood frog, held by an Amphibian Crossing volunteer. Photo by Mackenzie Hall.
Salamander Crossing
The volunteers take their places. For the next few hours, each person will walk a roughly 50-foot stretch along the dotted yellow traffic line in the middle of the road. Volunteers will tally any amphibians that pass through by number and species. The salamanders and frogs cross the road to get from their upland wintering areas to the vernal ponds on the other side, where they can safely lay their eggs. These vernal ponds, or temporary pools, dry up for part of the year. That means no fish are present to eat the amphibian eggs and tadpoles.
“We focus not only on salamanders, but on amphibians as a whole, because they are ecological indicators,” says Kris Schantz of New Jersey Fish and Wildlife, who started the migration night surveys in 2002 and has run them every year since. “They play an important role in helping us understand the ecosystem health, water availability, and water quality. If there are problems with the water, we will see it in them first.”
Schantz, along with MacKenzie Hall from the Conserve Wildlife Foundation of New Jersey and Mike Anderson from New Jersey Audubon, works with municipalities to coordinate these rural road closings for two or three nights each year. Yet Schantz is also calling for a permanent solution: culverts underground. Such systems are in place in Massachusetts and Europe, but have not yet been tried in New Jersey, which has more roads per square mile than anywhere else in the country. Culverts would do wonders here.
The first three-hour shift is ending without a single crossing. I say my goodbyes and begin walking back to the car. And then – “Spring peeper!”
“Salamander!”
A volunteer shines his beam on the spotted salamander, a good six inches of stunning dark blue dotted with bright yellow spots. A few feet away, the spring peeper – a tiny tree frog no bigger than my thumb, with a beautiful darkened X pattern across its olive-colored back – slowly makes its way across the road. It feels great to see these brave individuals, who appear to be testing the conditions for the rest of their groups – perhaps they are the amphibian equivalents of “guinea pigs.”
Oasis in the Forest
While state surveys are manned only by trained volunteers, there’s another opportunity for anyone to experience a salamander migration first-hand. Each March and April in East Brunswick, the town closes down a half mile of Beekman Road to drivers for a handful of rainy nights. Scores of local residents gather to observe the migration, watching spotted salamanders, spring peepers, red efts, and red-backed salamanders.
This unique public event started in the early 2000s when environmental scientist David Moskowitz found his first dead salamander on the road. He told then-Mayor William Neary about it, and the mayor was surprisingly receptive to closing the road. Each year since, the rural road has shut down for up to nine nights, depending on the quality of each mass movement.
The crossing attracts large numbers of participants, largely because it seems like such a different world in the middle of suburban East Brunswick. During my visit to the crossing, the frog calls echo so loudly that I might as well have entered a tropical rainforest.
“On many nights, we actually have a parking problem, so many families want to come out,” says Moskowitz. “Our message is that the perfect analogy of the vernal pool is the oasis in the forest. If you lose a vernal pool, you lose all of those species that go into a vernal pool.”
Ten Years Gone
In the decade since Wild New Jersey was published, the amphibian crossings in northwestern New Jersey have continued each year, though with some scaling back in 2020-21 due to Covid safety restrictions. Christine Healy of Conserve Wildlife Foundation manages the 2021 crossing project, and MacKenzie Hall still provides major oversight – albeit now as a New Jersey Division of Fish and Wildlife scientist.
David Moskowitz continues to manage the East Brunswick amphibian crossing, attracting hundreds of people each spring to safely enjoy the wonders of seeing these unique creatures, including introducing many people to the first close-up looks at a salamander or spring peeper. Visit the environmental commission’s project webpage for a detailed overview and regularly posted updates of conditions and likelihood of the road closing during this time of year.
– David Wheeler, March 2021
*Special Note, March 18, 2021*
Tonight’s forecast calls for relatively ideal conditions, so be sure to check out the East Brunswick salamander crossing updates for the likelihood of a road closure and the chance to visit the amphibian migration tonight!
Stay tuned for April’s installment of “Wild New Jersey Revisited” – a trip to the “Bayshore Bayou” in search of bald eagles!
Read the previous installments of Wild New Jersey Revisited:
