Members of the Nicola Naturalist Society will continue to monitor tiny toadlets as they migrate using a special underpass designed to protect them from being run over by cars in a provincial park.
Western toads, which are recognized as a threatened species, breed in a pond known as “West Pond” between Kentucky and Alleyne Lakes. In the late summer, the newly born toadlets migrate en masse from the pond to the woods, where they live for a few years before returning to the pond as adults to breed.
However, their migration pattern takes them right across a busy road leading to Kentucky Lake campgrounds during the camping season’s peak.
The toadlets are about the size of an adult’s thumbnail.
Nicola Naturalist Society members surveyed the area in 2012 to figure out how it could help the toadlets cross the road.
In May 2013, BC Parks installed a toadlet underpass. That summer, Nicola Naturalist Society volunteers spent 184 hours installing a low-lying fence to funnel the toadlets to the tunnel, monitoring the toadlets, and explaining the project to people visiting the area.
The fence, which stands 30 centimetres high, extends 60 metres to the east of the tunnel entrance and 30 metres to the north.
Although breeding in 2013 resulted in a much higher number of toadlets than in 2012, the mortality rate of migrating toadlets was lower, Nicola Naturalist Society president Alan Burger said at the group’s meeting on Jan. 16.
The tunnel seems to have been well-used, Burger said.
“During peak migration, there was a steady stream of toadlets going through the tunnel,” he said.
To help volunteers in their monitoring, a time-lapse camera was installed to take a picture every 15 minutes. Those pictures showed 7,481 toadlets entering the tunnel.
The total number of roadkill toads observed by the society’s volunteers in 2013 was 1,492.
Many of the dead toadlets had made their way around the east end of the fence, getting back onto the road.
Traffic is not the only cause of death for the tiny toadlets: many die of natural causes, such as dehydration, or become a snack for predators.
Still, Burger noted those numbers are rough, and the actual number of toadlets using the tunnel is likely much higher.
A discrepancy between the number of toadlets monitored entering the tunnel versus the higher number of them exiting could be an indication the toadlets use the tunnel as a sort of overnight refuge, Burger said.
Among its goals in the project for 2014 is to instal a more permanent, esthetically-pleasing fence, and to extend the east side of the fence further to catch more young Western toads as they migrate.
Although the park is closed during the spring migration of adults to breed in the pond, the new toadlets not only migrate during the park’s busiest season, but even during its busiest hours. The time-lapse camera showed the toadlets mostly crossed the road in morning and evening.
The two-year project was spearheaded by Nicola Naturalist Society in conjunction with B.C. Parks and herpetologists (zoologists who study amphibians) from Biolinx Environmental Research in Victoria. The project was funded by the Parks Enhancement Fund to the Nicola Naturalist Society and the Habitat Conservation Trust Fund to Biolinx.
For the full December 2013 report on the project, visit the “Projects” tab at nicolanaturalists.ca.