Conservationists strive to save migrating toads
Brief but perilous journey in Chilliwack crosses two-lane road during 10-day span
VANCOUVER It is one of the greatest, if tiniest, terrestrial migrations in North America, an estimated 100,000 western toadlets making their annual, overland trek from the pond of their birth in Chilliwack, across a farm pasture, and into a bordering forest.
The distance is only a two-minute walk for humans. But for the brown toadlets — about the size of your thumbnail — the journey is fraught with dangers. There is the unknown number of invasive bullfrogs lurking in the pond, the field grasses rustling with predatory garter snakes, and, worst of all, the fast-moving motor vehicles on two lanes of asphalt in their path.
“It’s sad to see a lot of them get hit because people are driving up and down,” says Sofi Hindmarch, a biologist with Fraser Valley Conservancy.
To improve the odds, in 2015, conservationists created a tunnel under Elk View Road in the Ryder Lake area, and put up 350 metres of black plastic fencing in an effort to direct the toadlets towards the tunnel — and safety.
It doesn’t always work. The toadlets can get around the fencing and be squished by motorists who refuse to take a simple voluntary detour on Ryder Lake Road that would avoid the area during the 10-day migration.
“It’s only 400 metres difference,” Hindmarch said. “That turns out to be 24 seconds if you drive 50 kph.”
Making matters worse, the to ad lets seem top refer to move across the road when it is busiest — sunrise to noon, and early evening to dusk.
The road is also increasingly popular with hikers destined for Elk-Thurston mountain trail, providing access to the alpine. Outdoor clubs in the region have been urged to tell their members to take the detour route at this time of the year, said Hillary Rowe, outreach co-ordinator for the conservancy.
While Hindmarch and Rowe monitor the toadlets, including a dozen or so clumping together on an exposed rock for warmth, Bob Stanton, a retired federal fisheries hatchery manager, drives up for a chat. A resident of the Ryder Lake area for about 30 years, Stanton says locals have known about the toadlet migration long before conservation efforts started about a decade ago. “I ran over lots in my day,” he says.
The tunnel has a sign warning the public to stay back, or else the toadlets will scurry away.
Masses of them do make it through the tunnel and scramble up the slope into the forest.
“Peek over the edge and you can see them coming out,” Rowe said.
The number of toadlets varies from year to year, but 2018 is looking like a good crop — an estimated 100,000-plus, compared with 7,500 in 2017 and 30,000 in 2016.
“This is probably a big year,” Hindmarch confirms.
Western toadlets also occur in the Lower Mainland in Langley township and Mission, but only Ryder Lake has a designated tunnel and systematic monitoring. Funders have included the Habitat Conservation Trust Foundation and the federal government.
The western toad is considered a species of special concern in Can- ada, and has a wide distribution in western North America.
At Ryder Lake, the pond, pasture, and forest are all on private land, highlighting the need for formal protected area status for critical habitat.