The West Coast is hopping up its efforts to help amphibians cross highways safely.
The region serves as an important habitat for Northern Red-legged Tree Frogs, a species at risk that pays the area back for its hospitality by distributing vital nutrients while migrating between wetlands and forests.
“They are really key parts of the ecosystem,” Dr. Barb Beasley, founding director of the Association of Wetland Stewards for Clayoquot and Barkley Sounds, told the Westerly News.
“They move back and forth, so they’re like these little nutrient energy packets moving through the forest. It’s a migratory animal that is taking nutrients across the landscape so, if we block them off or kill them off at roadways, then we’re interrupting that whole ecosystem process and that’s not a good thing to do.”
The Pacific Rim National Park Reserve recently installed three tunnels under the highway between Tofino and Ucluelet to help amphibians migrate across the landscape without getting run over by motorists.
Parks Canada spokesperson Nancy Hildebrand told the Westerly that the tunnels are 17 meters long with a hopping clearance of about 30cm and were constructed as part of the work being done to build a roughly 25 kilometre path through the Park Reserve.
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She said the preparation work to construct the path included identifying and protecting potentially impacted species, like Northwestern and Wandering Salamanders, Pacific Tree Frogs and Northern Red-legged Frogs.
“Swan Lake Wetland is located approximately 500 metres from the road and is an essential breeding habitat for many species; notably the Northern Red-legged Frog, which is a species of concern. These crossings, which are similar to culverts, were installed ahead of the important migration period,” she said.
“The crossings are equipped with directional fencing and a lock block wall, which stops amphibians from crossing the road and funnels them into the crossings. Soil and logs have been placed inside to provide natural cover and to help encourage amphibians to cross through.”
She added that the decision to build the tunnels, as well as their locations, was largely guided by data collected by Beasley.
“The data shows that the frequency of road mortalities of amphibians in this area is very high compared to other locations in the Park Reserve. Dr. Beasley has worked closely with the project design engineers and construction crews to ensure that the culvert design and placement would encourage amphibians to make use of them,” Hildebrand said.
The Association of Wetland Stewards installed a similar tunnel under the highway in 2011 and Beasley said the association’s monitoring of that tunnel shows they are helping not just amphibians, but other creatures as well, like salamanders, mink, marten, ermine and even black bears.
Beasley added that the Park Reserve’s three new tunnels will reduce road mortality and boost connectivity to different habitats on each side of the highway.
“It’s been really heartbreaking to see hundreds to thousands of animals that would get killed on that stretch of highway every year so if we can do anything to minimize or reduce that amount of mortality, that’s a good thing,” she said.
The association recently wrapped up another project to help amphibian migration, working alongside the Central Westcoast Forest Society to create a path over Lost Shoe Bridge #1.
“It’s a very eventful year for the red legged frogs here this year,” Beasley said.
She explained that bridges built in B.C. are “armoured” with coarse angular rock material called riprap to limit erosion, which makes it difficult for frogs to cross as they often get stuck between jagged crevasses.
“It really does cause some issues for wildlife passage, especially if you’re a little frog and you’re trying to make your way through this riprap, it’s very challenging,” she said.
The team covered the riprap with sand and rounded grovel to create a path for frogs so that they can cross without getting stuck.
Beasley said the project was made possible by funding from the Habitat Conservation Trust Foundation and support from the Ministry of Transportation.
While the new migration boosters will be a boon to frog populations, Beasley cautioned that the species faces a tough road ahead due to a variety of factors, including logging and climate change. She suggested a breeding area east of Swan Lake was logged in 2016, which coincided with a dramatic drop in the Red-legged Tree Frog population.
“They’re getting killed by cars on the highway, but they’re also losing habitat because of logging that’s happening around them,” she said. “It’s not just one thing, it’s a whole suite of issues or factors that cause declines in populations. By addressing the roadkill issue, we are helping to bolster the chances of the population surviving all of these other potential detrimental effects around them.”
She added climate change has brought dangerously colder and dryer winters to the West Coast’s amphibians, as well as more severe droughts during the summer, putting local amphibians in peril.
“If it weren’t for all the good people that are working to try and address the threats that these species experience, they would be toast. They would decline and it would be very perilous for them. And, I think, the perils are not going away, so there’s a need for continued vigilance and trying to restore habitats, habitat connectivity and protect habitats,” she said.
“They’re a huge component of the food web because they’re predators of small invertebrates living in the soil, so they have an influence over how soil is decomposed and they’re also prey items for all these other things like birds and mammals like the mink and the martin and ermine. They’re the basis of how the world works out here. If we don’t have all of these animals as a part of our ecosystem, the ecosystem is going to not produce all the things that we benefit from…They’re part of a big picture. Hishuk ish tsawalk. Everything is connected, everything is one.
Anyone wanting to support the association’s efforts is encouraged to reach out through its Association of Wetland Stewards for Clayoquot and Barkley Sounds Facebook page or emailing wetlandstewards@gmail.com.
andrew.bailey@westerlynews.caLike us on Facebook and follow us on Twitter
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