After three years studying amphibian populations with the help of keen Calgarians, researchers have learned it’s not always easy being green within the city’s urban confines.
The citizen-science study, Call of the Wetland, was led by the Miistakis Institute, a conservation research organization supporting evidence-based natural resource and land management decisions throughout the province.
The project, with partners including The City of Calgary and Enbridge Inc., involved volunteer observers visiting 52 wetland survey sites throughout the city during the spring and summer from 2017 to 2019 to detect and record amphibians with the help of a handy smartphone app.
Amphibians were an ideal choice for the citizen-science initiative to study because they are easy to identify, explained Tracy Lee, senior project manager with the Miistakis Institute.
“We chose amphibians because they are something that people like to see, that people can easily identify, and have distinct calls,” said Lee.
They were also selected because their distribution throughout the city was poorly understood, and they’re effective indicators of environmental trends, she explained.
“Amphibians breathe through their skin so they’re quite sensitive to changes in their environment, so they were a good species group to monitor to understand what’s happening in the city.”
Some amphibians are more tolerant to urbanization
While historical records of six amphibian species exist for Calgary, only three species were detected throughout the surveys, said Lee.
Missing were the western toad, Canadian toad, and northern leopard frog, which haven’t been seen in the city for decades.
The species detected through the three years of surveys — boreal chorus frog, wood frog, and tiger salamander — are likely more resilient to environmental change.
“We found three species that are probably more tolerant to urbanization,” she said.
These species weren’t ubiquitous, however, as these amphibians weren’t observed at six (14 per cent) of the wetlands.
It seems that wetlands around the city limits and those located in larger protected areas are more likely to support amphibian populations than those located near its centre, explained Lee.
“Around the edges of the city where we haven’t developed yet and through parks is where we are still seeing good distribution [of amphibians],” she said.
“Whereas in the inner city where we have some isolated wetlands, we have sort-of, though not completely, wiped them out.”
Data being used to understand amphibian distribution in Calgary
While the researchers couldn’t say for sure what is driving these trends, a team at The Calgary Zoo is now sifting through the data. They produce models to understand the factors driving the observed patterns of amphibians in the city.
“We haven’t finished that analysis, but the goal of this is to determine which species we still have, where are they occurring, and what is influencing their occurrence,” said Lee.
Call of the Wetland was an opportunity for Calgarians to learn about the city’s wetlands, an estimated 90 per cent of which have been lost, said Lee.
“Wetlands have such an important value to us ecologically that we need to be aware of them and try to preserve those that we have left.”
The volunteer observers — which numbered about 100 people per survey year — were keen to help catalog the city’s amphibians and helped collect quality data, said Nicole Kahal, the local coordinator for the project.
“There was a lot of excitement that they could see amphibians in the city,” she said.
“A lot of people would tell stories about how they used to see tiger salamanders in their backyard when they were kids, so they were excited to get out there and explore.
“This project was a great example of collecting quality data through citizen science.”