(Un)Safe passage: amphibians on the move
By Maleea Acker, July 2016
Habitat Acquisition Trust volunteers help to save local frogs, salamanders and other amphibians.
ONE NIGHT LAST SPRING, when John Potter and Joan Hendrick were out scanning a kilometre of dark, rainy road by their house in the Highlands, a woman stopped her car to ask if they were looking for something. “Yes,” replied Hendrick, “dead amphibians.” She laughs as she tells the story, but she can’t picture a rural road on a warm, wet night these days without thinking of the casualties likely happening around the region. “I didn’t understand,” she says, “until I started walking. You see them everywhere.”
During summer’s heat, as residents enjoy the local lakes and the winding roads of Saanich and the Highlands, it’s easy to forget the creatures that live alongside in forests, fields and wetlands. But come September’s rains, amphibians like rough-skinned newts, long-toed salamanders and red-legged frogs will make a treacherous journey across these lanes of traffic.
The region’s amphibians complete two migrations a year. In early spring, they move from upland forests to lower wetlands to find mates and lay eggs. In August and September, they journey in reverse, back to their winter forests. Unfortunately, many of the region’s rural areas have roads that bisect this migration route. On parts of West Saanich Road and Munn Road, the mortality of these species can be shockingly high. In one night in 2015, volunteers counted 369 dead amphibians (mostly Pacific tree frogs) on one curve of West Saanich. Almost 100 more were counted at the hot spot near the Potters’ house on Prospect Lake Road.
Potter’s and Hendrick’s observational tasks are part of their work as long-term volunteers with Habitat Acquisition Trust (HAT), a non-profit conservation organization that helps to preserve and restore native ecosystems around the south island.
HAT began its Amphibian Roadkill Project in 2015 and now coordinates with volunteers around the region. Volunteers—usually clad in raincoats and reflective vests—complete counts of amphibian mortalities, including species type and number and GPS location, recording the data on waterproof paper that HAT supplies. They also help amphibians across the road, picking up the slow-moving newts and salamanders and carrying them from one side to the other. Since learning the places where amphibians tend to migrate, Hendrick says that she’s become more careful. “I’ve been yelled at for hitting the brakes for a frog when driving,” she admits.
More than 20 species of frogs and salamanders make their home in BC, with many concentrated in the southern part of the province, where low, temperate wetlands provide ideal habitat. The word amphibian means “double life,” and refers to their larval and adult stages, when they transform from aquatic, gilled animals into air-breathing, land-based animals.
Amphibians are key players in the planet’s web of life. They eat insects, help to protect agricultural crops, and serve as prey for larger animals. But amphibian numbers are in decline world wide; their sensitive, porous skin makes them among the first casualties from pesticide run-off and other water pollutants, habitat change, and ecosystem fragmentation. Because they are so sensitive, they act as an indicator species, warning of potentially dangerous environmental conditions that could also harm human health.
Despite their key role, Alanah Nasadyk, the Community Outreach and Development Coordinator for HAT, tells me that relatively little is known about breeding ground locations for amphibians in the region as well as the species that inhabit them. The Environmental Studies department at UVic came into being only in the late 1990s, she explains; for the Capital Region, knowledge of habitat and number of species is research that just hasn’t yet been done.
Potter and Hendrick, along with other volunteers who patrol local roads, pass their information to HAT, who have created species maps for Highlands, Metchosin and the CRD as a whole, as well as hot spot maps where casualties tend to be particularly high. “We’re really relying on citizen science,” stresses Nasadyk. HAT hopes that zeroing in on hot spots could help convince governments to build amphibian tunnels to provide safe passage under, instead of over, roads, as well as to post signage, warning drivers of crossings. They would also like to see increased study of diseases specific to amphibians, which is where broader scientific collaboration comes into play.
The results of the volunteer field work and HAT’s mapping efforts aren’t useful just to the region. HAT also works with the University of Victoria’s Microbiology Department, where the department’s lab focuses on applying what is known about human health to animal health. Some HAT volunteers recover the remains of amphibians who have died crossing the region’s roads. If they’re in passable condition, they donate them to UVic, where Caren Helbing, professor of microbiology and biochemistry, is happy to receive them. “It’s an exciting and critical partnership,” says Helbing, as HAT provides much of the fieldwork that the lab can’t always do. Helbing stresses that UVic’s research concentrates on non-lethal methods as much as possible. In one nook of the lab, four bullfrogs in various stages of transformation from tadpole to mature frog bump their noses against their plastic bucket. But the acquisition of a rare species, even if it’s no longer alive, is a welcome gift.
Helbing’s lab recently completed the first sequencing of the frog genome. When I visit, she pulls out small test tubes of a white, nebula-like material floating in liquid: pure DNA, millions of strands in each vial. Using DNA pulled from species collected by HAT, Helbing’s lab is advancing research on how metamorphosis occurs in amphibians, how their health can indicate wider patterns of health in the animal world (in species such as Beluga whales, spot prawns and mussels), and the health of a region’s water supply. In the CRD, persistent organic pollutants (POPs) like polybrominated diphenyl ethers (PBDEs), which can act as endocrine disruptors, have recently been found in the region’s river otter populations. Endocrine disruptors change hormone levels in animals. Higher levels of thyroid hormone can disrupt or alter metamorphosis for amphibians and cause changes in sex organs and the development of tumours. Tracking the presence of POPs can help indicate amphibian health—and human health—around the region.
HAT’s goal is primarily to raise awareness of impacts amphibians face not just through road mortality, but through the introduction of amphibian diseases from Europe and Asia. Many families buy foreign salamanders or newts as pets; diseases can accompany them. When the aquarium has served its purpose, too often the water is dumped into local waterways or down the toilet, which can spread fungal diseases like Bsal, an amphibian fungal disease responsible for significant amphibian deaths in other parts of the world. Helbing thinks it’s only a matter of time before these diseases reach North America, and wetlands like those in the Highlands.
During my visit to Potter’s and Hendrick’s home, over a dozen bird species mob the feeders outside their windows. They also have a neighbourhood bear that visits from time to time. They boast of not having to mow a lawn, and it’s obvious that the region’s natural habitat is impetus to their need to volunteer, not only through amphibian counts but by installing bat boxes for HAT, restoring native ecosystems with the CRD and enjoying work parties on Haliburton Farm. “Your level of awareness,” she tells me, “really increases. There are lots of little creatures out there, you just have to look for them. You think of that on rainy, warm nights.”
Maleea Acker is the author of Gardens Aflame: Garry Oak Meadows of BC’s South Coast (New Star, 2012). She is currently completing a PhD in Human Geography, focusing on the intersections between the social sciences and poetry.