Traffic kills thousands of toadlets during mass migration in Chilliwack, B.C.

Liam Johnson and Emily Siemens slowly make their way up a hilly, rural road in Chilliwack, B.C. Clad in high visibility vests and wielding the tools used to conduct a toad-monitoring survey, they squat in the middle of the road, carefully counting little blotches on the asphalt.

Meticulous and patient, the volunteers — both university students — are helping Fraser Valley Conservancy track the annual mass migration of toadlets from the wetlands near Ryder Lake to the surrounding forest.

The count is aimed at tracking the local western toad population, and the toll human activity is taking on the creatures.

But for the most part, they're counting the mass casualties caused by traffic on the road.

"It's pretty sad. It's kind of hard to keep counting when you've been going thousands and thousands," said Johnson on Thursday. "But it's encouraging because there are even more alive ones that make it across, I think."

It's too early to know how many tiny Western toads are making the once-in-a-lifetime trip this year, but according to project coordinator Sofi Hindmarch, it looks like a pretty big year.

"We're probably having, I would say, in the hundreds of thousands of toadlets going up during the seven-to-10 day period," said Hindmarch.

She said the number of dead will likely be in the 15,000-20,000 range by they time the migration is over, despite conservation efforts, such as the black fencing that guides the toads into a tunnel under the road.

But thousands of toads will miss the tunnel and get crushed by traffic instead.

"We're fortunate enough that we have a tunnel — It's a toad tunnel," said Hindmarch, who started working on the Ryder Lake toad migration three years ago, a year after the tunnel was installed.

The Ryder Lake toad migration is one of several in B.C. There are similar efforts to protect the little critters in Coquitlam, Mission, Squamish, Whistler and Langley.

At Ryder Lake, the critical stretch of road is just 300 metres long, and Hindmarch's group is asking anyone traveling through the area to follow the voluntary detour.

"It is actually a fantastic thing to come and watch. Please follow the directions to the safe parking area and please respect the toads," she said. To avoid disturbing the toads, Hindmarch said people should stay out of the area completely and follow the migration on Fraser Valley Conservancy's website and social media accounts.

"We encourage people to follow the migration from there," she said.

When a van slowly passed through the sensitive section of road on Thursday, she scowled.

"That's the third time that car has gone through today," she said, adding that the slow speed doesn't prevent unnecessary deaths — the camouflaged brown and green toads are nearly impossible to see from a vehicle, and even a cautious driver will run them over.

"We are really grateful for people that use the detour," Hindmarch said,

She said that most of the locals support the conservation efforts and steer clear throughout the duration of the migration.

"Every minute there's not a car on this road will save toads."

Follow Rafferty Baker on Twitter: @raffertybaker