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Each spring, thousands of tadpoles and toads take part in a
dangerous migration, crossing roads and paths. Researchers are discover-
ing new ways to help them out
To a d
M i g r a t i o n s
o f
B r i t i s h
C o l u m b i a
Story & Photos By
Isabelle Groc
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Toads moving back and forth between forest and wetland
could cross a road three times a year, or more.
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n a sunny summer afternoon in July, the sandy beach of Lost Lake, a 15-minute walk from Whistler Village, is packed. Kids splash
in the water, cyclists and walkers stop by after a hike in the surrounding trails, oth-ers simply sunbathe on the grass.
In a warm shallow area of the lake, thou-sands of visitors also enjoy the sun. They are black and shiny and swim together in the sun rays, forming what looks like an abstract painting. They are western toad tadpoles hanging out in large groups. Eventually the tadpoles will transform into tiny thumbnail-sized toadlets. They will leave the lake en masse later in the sum-mer and move to the nearby forested areas of Lost Lake Municipal Park.
“Watching the tadpoles in the open wa-ter is a pretty magical time. It is amazing how they move, they are schooling in the water like fish,” says wildlife biologist Ja-kob Dulisse. “It is as spectacular as the salmon migration or the great wildebeest migration in Africa.”
EvEry summEr, in different parts of Brit-ish Columbia, thousands of tiny toads mi-grate from the wetlands where they were born to the forests where they live the rest of their lives. The journey is danger-ous. As the toads have to cross roads and trails, they often end up being squished by passing cars or stepped on by people. It is not just the baby toads that get killed on roads. In early spring, the adults leave the forest for the shallow waters of ponds and lakes where they congregate and breed. The females lay an average of 12,000 eggs in long strings that look like black beaded necklaces. Once they have finished breed-ing, the toads return to the forest to eat and get ready for their winter hiberna-tion. Every time they move back and forth between the wetland and the forest, they cross roads and get hit.
“One of the really unique things about western toads is their communality in terms of behaviour,” says amphibian biolo-gist Elke Wind. “They all come together to breed at the same time and then you have all the tadpoles hanging out together, and the toadlets are coming out at the same time.” While mass migration makes sense to avoid predators, humans have introduced new dangers. “When you throw a road in front of the migration, now all of a sudden this evolutionary adaptation becomes a big hindrance for the toads,” Wind says.
Vulnerable to urban development, road mortality and disease, there is concern
that the warty amphibians have declined in some areas in the province, particularly in the Fraser Valley region and Vancouver Island. They are listed under the federal Species at Risk Act as of “special concern.”
in an Effort to better protect toad habi-tat on Vancouver Island, Elke Wind con-ducted a study in the Cowichan Valley to
learn more about what winter hibernation sites toads prefer, and how far they travel. She captured toads, placed radio transmit-ters on them and followed the amphibians for three years. Wind was surprised to dis-cover how far the toads travelled in the fall, before moving closer to their breeding site for hibernation. As a result of these exten-sive movements, all toads crossed at least
o
Checking out a western toad tadpole aggregation at Lost Lake, Whistler.
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one road. “They move around so much, that blows my mind when you think of their size,” Wind says.
People across the province are trying to make those landscapes safer for the am-phibians and reduce the dangerous inter-actions they have with humans.
At Lost Lake in Whistler, as thousands of toadlets emerge from the lake to migrate
to the forest, they travel across trails at the height of the busy summer season. “There are lots of people and lots of toads,” says Heather Beresford, environmental stew-ardship manager for the Resort Munici-pality of Whistler.
Over the years, the municipality in-stalled signs and fences and posted vol-unteers to educate the public about the
Western Toad Range
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migration. In the last two years, in order to better protect the toads from being run over by drivers, bikers and walkers, the park’s access road, parking lot and beach area were closed during the peak migra-tion in August. “It was significant when you think of all the people that go there to spend the day at the park,” Beresford says. “We wanted to do what we could to protect that migrating population.”
In the Lower Mainland, Minnekhada Regional Park in Coquitlam also has a population of western toads. However, the park’s trails are very popular and in early July, migrating toadlets use the same trails as people. Metro Vancouver staff have in-stalled signage to alert inattentive hikers and cyclists. “We make people aware that toads are in the park and that they can impact them by stepping on them,” says Markus Merkens, natural resource man-agement specialist for Metro Vancouver. “People might look at the park differently as a result.”
HikErs may BE able to walk more slowly and avoid toads on trails, but managing cars on highways is a different story.
In June 2017, Tim James patrolled high-way 31A between Kaslo and New Denver, driving slowly and looking for adult breed-ing toads at night. When he found one, he picked it up carefully off the road so the amphibian could safely continue its jour-ney. “Helping animals is just a wonderful feeling,” James says. “You can’t imagine sweeter animals than toads. They seem really calm when you pick them up and move them off the road, it is so endearing.”
James is one of the volunteer toad am-bassadors the Valhalla Wilderness Society recruited from the general public to help out a population of toads at Fish and Bear
Lakes in the West Kootenays. The society estimates that on average one to two adults migrating across the highway to breed are killed every night by cars in the spring. In May and June 2017, volunteers moved 330 toads off the highway over 20 nights, according to Marcy Mahr, a biologist with the Valhalla Wilderness Society. Mahr spends a lot of time educating the public about toads, the threats they face, and how people can help.
“There is something very accessible about toads. We can see how toads are developing and how this massive mi-gration is happening,” she says. “You see
Children from NatureKids BC are doing a night road survey, counting amphibians on the road.
This toad fence directs toads toward a tunnel.
Jakob Dulisse checks the camera in a toad tunnel
along Summit Lake.
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nature unfolding.”In the Kootenays, Summit Lake is known
as the largest breeding site for western toads in B.C. But every year, substantial numbers of adult and juvenile toads are killed by vehicle traffic on Highway 6 as they migrate to and from the lake. “Twenty years ago, the roads would get slippery be-cause there were so many toadlets,” says Jakob Dulisse who monitors the popula-tion. “That does not happen now because the population is getting smaller.”
In 2014, the Ministry of Transportation installed a concrete tunnel to help toads safely cross the highway. According to Dulisse, hundreds of toads and other spe-cies are using the tunnel ever year, but it is not enough. “We can’t still prevent all the highway mortality and there will be more traffic,” Dulisse says. He indicates more tunnels are needed and that it would also be helpful to change patterns of traffic at night, especially during the adult migration period, asking, for example, commercial drivers to avoid the highway at certain times of the year at night.
In the small community of Ryder Lake in Chilliwack, community residents were also concerned about the toads that were killed ev-ery year on the road. Other amphibians were also run over, including northern red-legged frogs, northern Pacific tree frogs, roughskin newts and salamander spe-cies. For the last 10 years, the local community tried dif-ferent approaches. At first, volunteers picked up toads and carried them across the road in buckets during the migration. “It didn’t solve any problems, but it raised awareness,” says John Viss-ers, president of the Fraser Valley Conser-vancy, which coordinates the Ryder Lake amphibian protection project.
Road closures and voluntary road de-tours were also implemented, but a more permanent solution was needed. Volun-teers went out on rainy nights in the early spring to count amphibians on the road and determine where the hot crossing spots were. In June of 2015, an amphibian crossing structure was installed in the lo-cation where the most toads crossed the
road, and additional fencing helped guide migrating toads into the tunnel. That year, over 11,000 toadlets were observed using the tunnel in June and July. However, in 2017, the tiny toads headed in the oppo-site direction of the tunnel. “I suppose we can’t be really imposing behaviour on the toads,” says Vissers.
HElping toads Cross roads is not the only challenge conservationists face. Toads live in two different types of habi-tats, aquatic and terrestrial. As such they are part of a complex food web and play an important role, transferring nutrients from the wetland to the forest. “They are
like the salmon of the wetland world,” says Elke Wind.
But for toads to survive they need both habitats to be protected. “They require healthy aquatic and terrestrial environ-ments, and a connection between the two,” summarizes Dulisse. At Summit Lake, concerned community residents and en-vironmental groups have not only been concerned with road mortality, but also with logging of the forest habitat the toads use as well as proposed ATV trails. In
• If you are walking or biking on trails in parks that are also used by amphibians, open your eyes, watch your step and do not squash tiny toads.
• Avoid toad breeding aggregations. This is a very sensitive time for the amphibians—do not disturb them.
• Do not touch amphibians unless necessary. They have very sensitive skin, and if you wear sunscreen or other products, you can harm them. If you are observing a tadpole aggregation, do not touch and pick up tadpoles in buckets. View with your eyes and not your hands. When toadlets are migrating, do not handle and pick them up unless you are
working under the supervision of a naturalist with gloves on. Keep dogs away and on-leash.
• If you live near a toad breeding area, make your property toad friendly. On Vancouver Island, research has shown that toads use woody structures such as logs and stumps to hibernate in the winter. Do not remove larger trees, stumps and logs on your property: they are part of toad habitat. Avoid mowing your field or lawn where toadlets can be found during migration.
• Avoid driving on roads where toad migrations are known to occur. Use alternate routes. Avoid driving on wet spring and fall nights when
amphibians are moving to and from breeding sites. If you come across a toad on the road at night, move it if off the road in the direction that it was travelling (if safe to do so).
• Join public education events and volunteer. Every summer the Fish and Wildlife Compensation program organizes a Toadfest at Summit Lake Provincial Park, where you can learn everything about toads and other species that share their habitat. At Ryder Lake, the Fraser valley Conservancy often needs volun-teers to help with amphibian night surveys and building fencing. Check out naturalist groups that may have amphibian monitoring programs in in your local area.
Fraser Valley, many wetlands have been lost. “If you I look at the Lower Mainland, between 80 and 90 percent of the wetlands that used to be there have been redevel-oped into other purposes like agriculture, residential or industrial areas,” says Metro Vancouver’s Markus Merkens. “That loss of habitat has left very little for the wild-life that depends on wetland ecosystems to maintain themselves.”
Ultimately, toads speak for many other species faced with similar threats. Alan Burger is a bird biologist who spent years doing research on the marbled murrelet, a small seabird. He did not know much about toads until he undertook a monitor-
ing project with the Nicola Naturalist Soci-ety on a population of toads at Kentucky-Alleyne Provincial Park near Merritt. Like toads, murrelets use two different habitats, the ocean and the forest. “They are very different organisms, but there are overlaps in the way they use habitats and the ways that people are affecting them,” Burger says. “They run into similar problems.”
In the end, more public awareness of local migration patterns is a good thing for spe-cies across the province.
K e e pi n g T o a d s s a f e
There are many places to see toads in the province. When you watch tadpole aggregations in shallow water during the late spring and early summer (June and July) or encounter a toadlet migra-
tion in the summer (July and August), observe the following guidelines to keep toads safe:
