Every January, once the confetti has settled from the new year’s celebration, I start thinking a lot about amphibians and preparing for their springtime migration. That behavior, however, is not collectively adopted by all of our local frogs and salamanders. Different species have found different ways to adapt to the challenges of a complex lifecycle that relies on environmental factors to inform physiological changes. Wood frogs, as well as spotted and Jefferson salamanders, have conformed to an early spring breeding strategy. Once the ground thaws and snow melt has raised the water level in vernal pools, they are on the move. Since amphibians in temperate climates hibernate (or more correctly, brumate – the “cold-blooded” equivalent), you might think that their appearance in February and March means that they lead the pack. While this seems a reasonable assumption, it’s actually incorrect.
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:
Wildlife habitats all over the country have been broken into ever smaller pieces by human development, making it challenging for animals to safely find food, mates or a place to make a nest or den. This is especially true in New Jersey, which has more people per square mile than any other state by far.
The PBS EcoSense for Living episode ”Wildlife Crossings” has captured the challenges habitat fragmentation poses to wildlife, along with the amazing work that scientists, engineers, and wildlife managers are doing to help. Projects supporting New Jersey Division of Fish and Wildlife’s Connecting Habitat Across New Jersey (CHANJ) initiative, including CWF’s Amphibian Crossing Project, are featured beginning at 14:10.
On warm, rainy spring evenings salamanders, frogs and toads venture out for the most eventful nights of their year. They have but one goal – to make it to a vernal pool to breed. But between them and the pool is a road, filled with cars barreling along, completely oblivious to their big plans.
A single vehicle can crush dozens of these slow-moving animals as they try to make it across the road. From the driver’s seat they may look like mere twigs, leaves, or raindrops bouncing off the road. With high mortality rates year after year, it doesn’t take long for a population to nose-dive.
The Amphibian Crossing Program helps hundreds of salamanders, frogs and toads make that hazardous journey so they can have their big night. We are also assisting NJDFW in preparing for a wildlife crossing structure system consisting of under-road tunnels and guide fencing to help amphibians at our busiest migration site.
Successful “critter crossings” at this priority site could pave the way for many other projects, allowing salamanders, frogs, and toads (as well as snakes, turtles, and other small animals) to safely and independently cross between their upland habitats and breeding pools each spring. To see how the Amphibian Crossing Project fits in with other statewide projects supporting wildlife habitat connectivity see Connecting Habitat Across New Jersey (CHANJ).
Want to help? Volunteers for the Amphibian Crossing Project must complete a training session. If you are interested in being a part of next year’s project, please contact allegra.mitchell@conservewildlifenj.org.
Conserve Wildlife Foundation biologist Allegra Mitchell recently wrote about rare herps for Skylands Visitor’s website. Allegra takes you on a tour through the sometimes weird, always wonderful world of amphibians and reptiles.
As the season eases into milder temperatures at the onset of spring, all manner of creatures stretch their bodies and move more freely, searching for food and mates while they patrol their home turfs. Among these creatures are some of the most rare, interesting, and beautiful animals in the Garden State. Though they often go unnoticed or are misunderstood, reptiles and amphibians are vital to the balance of our fragile ecosystems—and some of them are in pretty big trouble.Continue reading on njskylands.com.
Road Closures Help Amphibians Migrate to Vernal Pools to Breed
Conserve Wildlife Foundation is excited to celebrate Amphibian Awareness Month during March 2015! Follow us on social media and be sure to check your email (sign up for our list) for weekly stories on the amphibians of the Garden State and our work to protect them.
On the night of March 14, Conserve Wildlife Foundation Communications Coordinator Lindsay McNamara attended the first closure of Beekman Road this season. Beekman Road, in East Brunswick, New Jersey, is closed to traffic about two or three nights for six to twelve hours each spring by Friends of the East Brunswick Environmental Commission(Friends of EBEC). Friends of EBEC organizes these road closures to maintain local biodiversity.
In the woods on either side of Beekman Road, vernal pool habitat exists. Vernal pools are temporary woodland ponds that fill with water during the winter and spring and dry out in the summer. These vernal pools are extremely important for a number of amphibians in the area. Spotted salamanders, wood frogs, green frogs, spring peepers, Fowlers toads and chorus frogs all rely on the vernal pools for breeding.
Some amphibians, like spotted salamanders and wood frogs are entirely dependent on the vernal pools for breeding. They leave their winter hibernation spots in upland forests and migrate (often in large groups) to the vernal pools. Research suggests that these species follow the same migratory paths each year, often traveling distances of as much as 1,000 feet from their hibernation spots.
At the vernal pool, mating occurs, eggs are deposited by the females, and the adults leave the habitat and venture to the surrounding woods. The adults spend their summer in these wooded areas before slowly retreating back to their winter hibernation areas, and the natural cycle begins again.
Unfortunately, the migrating amphibians need to cross Beekman Road to get from their hibernating spots to their vernal pool breeding grounds. Road kills during this journey significantly reduce salamander and frog populations and can lead to local extinctions at breeding ponds.
Friends of the East Brunswick Environmental Commission has worked together with a number of partners to close Beekman Road to traffic during nights when amphibian migration is extremely likely. These road closures help protect migrating salamanders and frogs as they move across Beekman Road to their breeding vernal pools.
Friends of EBEC consider a number of variables before they decided to close the road. A wide range of factors trigger salamander migration including the amount and timing of rainfall, the date, the temperature of the air, the temperature of the ground, the availability of open water on the vernal pools, the depth the salamanders are migrating, soil moisture and many others. Interestingly, studies have shown that males typically migrate first and arrive at the vernal pools before the females. It seems females need a higher average air temperature to stimulate their movement than the males.
Volunteers are encouraged to come on these rainy nights to help the amphibians cross the road. Bring your friends, your family and don’t forget a flashlight, to the next road closure of the season! Updates are posted on the Friends of the East Brunswick Environmental Commission’s blog.
These road closures are a great way to protect local biodiversity and educate New Jersey residents about wildlife in their state. Conserve Wildlife Foundation, in partnership with the New Jersey Division of Fish & Wildlife’s Endangered and Nongame Species Program, lead a number of Amphibian Crossing volunteer programs across New Jersey. Join us!
