Search

Wildlife Underpasses Can Reduce Amphibian Road Deaths by More Than 80%: Study

We are an online community created around a smart and easy to access information hub which is focused on providing proven global and local insights about sustainability

03 Jun, 2025

This post was originally published on Eco Watch

Amphibians like frogs and salamanders face mounting threats around the world, including habitat loss, climate change, deadly fungus and road mortality.

Roads pose an immediate danger by cutting amphibians off from crucial migration corridors and putting them in the path of vehicles, which kill millions of animals annually.

Now, a first-of-its kind study led by researchers from University of Vermont (UVM) shows that wildlife underpasses can reduce amphibian deaths by more than 80 percent while helping to preserve ecosystems.

Over a decade of research by scientists and citizens from the Vermont Agency of Natural Resources, the local community and University of Vermont assessed the effectiveness of a pair of wildlife underpass tunnels installed under a road located in Monkton, Vermont, a press release from UVM said.

A frog attempts to cross a road in Monkton, Vermont. Joshua Brown / University of Vermont

The two underpasses led to an incredible 80.2 percent fewer amphibian deaths.

“It was surprising. I knew that underpasses would work, but I didn’t think they would be that effective,” said lead author of the study Matthew Marcelino, an ecologist at UVM. “And when we took climbing amphibians out of the picture — which in our context are primarily spring peeper frogs — we noticed a 94% decrease in mortality in the treatment areas.”

The research team monitored the road mortality of amphibians in the area from 2011 to 2015 before constructing the underpasses and from 2016 to 2022 after construction.

They compared three zones: the first a treatment with underpasses and wing walls; the second a buffer area at and beyond the edge of the wing walls and away from the tunnels; and the third a control area far away from the infrastructure changes.

Standardized surveys were conducted during brief spring migration windows across a dozen species of toads, frogs and salamanders. Initially the team found a total of 5,273 amphibians, including 2,545 peeper frogs — almost 70 percent of which were deceased — and 1,702 spotted salamanders, almost half of which were also dead.

The death rates were significantly lower in treatment and buffer areas, where the animals had been using the tunnels rather than being displaced.

This underpass in Hallau, Switzerland leads to a wetland and was built for migrating frogs to avoid traffic. SiyueSteuber / iStock / Getty Images Plus

The study is the first to provide long-term evidence of the effectiveness of amphibian-specific wildlife underpass tunnels in the northeastern United States. It highlighted that design details such as wall height and angles, materials and tunnel layout make a difference.

“Amphibians — frogs, toads, and salamanders — play vital roles in ecosystems and are highly sensitive to environmental disruption,” the press release said.

Many amphibians in Vermont and a large portion of the Northeast spend most of their lives in upland forest streams or soils, including long winters underground. They emerge in early spring on temperate, rainy nights to begin their migrations from woods to wetlands, flooded meadows and ponds to breed.

“It’s usually sometime between late March and late April,” explained ecologist Brittany Mosher, senior author of the study and a professor at UVM’s Rubenstein School of Environmental and Natural Resources. “Many species will breed in the same ponds. So it’s not just a single species migrating — it’s many, many species. And oftentimes, we see hundreds or thousands making this movement all at the same time.”

Roads frequently stand in the way of amphibians’ journeys from upland forests to aquatic habitats.

“Planners — state and federal transportation planners — often build roads between these steeper forested upland habitats and nice flat aquatic habitats,” Mosher said. “So the roads are placed exactly in the wrong spot if you were an amphibian planner.”

Because they are small and move slowly, amphibians are particularly vulnerable to vehicle collisions.

“Unlike larger mammals that might dart across a road in seconds, frogs and salamanders can take several minutes to cross — and with hundreds migrating at once, mortality rates can be staggering,” the press release said.

The cost of the 0.81-mile stretch of road that the underpasses cover was $342,397 — much lower than that of large overpasses and underpasses designed for mammals, which can run anywhere from $500,000 to almost $100 million each.

The amphibian underpass design features two concrete tunnels that are four feet wide with wing walls that help guide them toward the tunnels and underneath the road.

The Lewis Creek Association used wildlife cameras to count 2,208 amphibians using one underpass in 2016. Other animals also took advantage of the tunnels, including bobcats, porcupines, bears, snakes, birds and racoons.

The researchers emphasize that their findings should be used as a model for policymakers and road planners across the country.

“This study provides strong evidence that wildlife underpasses work,” Marcelino said. “We hope this will encourage transportation departments to include them in future plans, when building or repairing roads.”

Mosher added that the underpasses are not only helpful for amphibians, but demonstrate that communities can work together to protect local wildlife.

“This story began with local community members who were engaged and concerned,” Mosher said. “And it provides a view for how other communities can protect their amphibian populations too.”

The study highlights the crucial role of research, community engagement and investment in targeted infrastructure to support biodiversity.

Conservation takes commitment,” Marcelino said. “But when we invest in good tools and take the time to do it right, the payoff for ecosystems and wildlife can be enormous. These are beautiful creatures — so beautiful, so ancient.”

The findings of the study, “Assessing the Efficacy of Wildlife Underpasses in Mitigating Amphibian Road Mortality: A Case Study from the Northeastern United States,” were published in the Journal for Nature Conservation.

The post Wildlife Underpasses Can Reduce Amphibian Road Deaths by More Than 80%: Study appeared first on EcoWatch.

Pass over the stars to rate this post. Your opinion is always welcome.
[Total: 0 Average: 0]

You may also like…

‘The Science Is What Sets Us Apart’: How the Rodale Institute Has Spent 77 Years Innovating Regenerative Organic Agriculture

‘The Science Is What Sets Us Apart’: How the Rodale Institute Has Spent 77 Years Innovating Regenerative Organic Agriculture

Founded in 1947 by J.I. Rodale, Rodale Institute is a nonprofit dedicated to helping the regenerative organic agriculture movement grow through research, education and farmer training. In his study of regenerative organic farming, Rodale — who came up with the term “organic” — studied Indigenous agricultural practices, including those of communities like the long-lived Hunza […]
The post ‘The Science Is What Sets Us Apart’: How the Rodale Institute Has Spent 77 Years Innovating Regenerative Organic Agriculture appeared first on EcoWatch.

Urban 'placemaking' focus for $85m recreation centre

Urban 'placemaking' focus for $85m recreation centre

Sydney developer Billbergia Group has announced the Rhodes Recreation Centre — an $85 million, 9200 m2 multi-purpose community hub in Sydney’s Inner West.

Located at 6 Gauthorpe St and designed by architectural firm SJB, the recreation centre is in a three-level podium building beneath two high-rise residential towers — the 48-level Peake and 43-level Oasis. Together, they form stage two of the developer’s Rhodes Central Masterplan — a $3 billion, three-stage town centre project.

The Rhodes Recreation Centre was delivered under a $97 million Voluntary Planning Agreement (VPA) between the developer and City of Canada Bay Council. It will be handed over to council next month and is set to open later this year. Once complete, the masterplan will have delivered 25,000 m2 of dedicated public amenity, including retail, community facilities and open space.

With the NSW Government’s housing reforms set to address the housing shortage, the recreation centre will reflect the importance of ‘placemaking’ — a collaborative approach to designing and managing public spaces that enhances community wellbeing and fosters connections between people and their environment — in planning new urban communities.

It also presents a pathway for public and private sectors to collaborate and create social infrastructure while increasing housing supply in fast-growing suburbs.

The recreation centre is set to add vibrancy and pedestrian activity to the local streetscape, providing a diverse range of facilities that enhance the livability of the evolving suburb. These community amenities include two full-sized indoor sports courts, a gymnastics centre, a 70-place childcare centre, a community lounge, allied health services, and bookable spaces for local groups and events. It also provides a gym with cardio equipment, weights, group fitness rooms, a creche and an outdoor terrace, alongside a range of sustainability features.

Facilities at the Rhodes Recreation Centre. Images supplied.

“Rhodes Recreation Centre is the community heart of our high-density TOD development, bringing to life Billbergia’s vision for a future-focused, livable urban environment that prioritises amenity, not just density,” said Saul Moran, Development Director – Planning and Design at Billbergia.

The amenities within the two residential towers include a swimming pool, spa, sauna, children’s play area, library and theatre rooms. Pedestrian connections and through-site links provide access to Rhodes railway station and the Homebush Bay waterfront.

“The Rhodes Recreation Centre stands as a benchmark in successful public–private collaboration. Through a VPA with Canada Bay Council, we’ve created a pathway to unlock additional housing supply while delivering significant, lasting community infrastructure. It’s a clear demonstration of how thoughtful public and private partnerships can shape vibrant, livable neighbourhoods,” Moran said.

Located adjacent to Rhodes railway station, stage one of Billbergia’s Rhodes Central Masterplan was completed in 2021 and included the 13,000 m2 Rhodes Central Shopping Centre, with convenience retail, a Woolworths supermarket, medical facilities and the Bamboo Lane dining precinct.

Other previous projects include the 1.2 ha Phoenix Park in Rhodes, the $63 million Bennelong Bridge, the popular Baylink Shuttle service, the 3500 m2 Wentworth Point Community Centre and Library, and the Wentworth Point Pop-Up Town Square.

Billbergia’s ongoing focus on placemaking and social infrastructure also includes the $8.4 million delivery of a library at its mixed-tenure development, Arncliffe Central, in Sydney’s south. There is the potential for 75% of Arncliffe Central’s dwellings to be dedicated to social, affordable and essential worker rental housing, along with 3400 m2 allocated to childcare, convenience retail and cafes, and a 4000 m2 park with play space for both residents and the broader community.

Top image caption: The Rhodes Recreation Centre location with two planned residential towers, Peake and Oasis. Image supplied.

Environmental Groups Successfully Petition Alabama to Update Water Toxicity Standards

Environmental Groups Successfully Petition Alabama to Update Water Toxicity Standards

A group of seven conservation organizations has successfully petitioned the Alabama Environmental Management Commission (AEMC) to update the Alabama Department of Environmental Management’s (ADEM) water toxicity standards for 12 pollutants. In April, the group filed a Petition for Rulemaking that argued that the existing water toxicity standards in Alabama did not properly protect public health, […]
The post Environmental Groups Successfully Petition Alabama to Update Water Toxicity Standards appeared first on EcoWatch.

0 Comments