Northern
leopard frogs considered a threatened species in Alberta-Endangered species
population ecologist Lea Randall says, “If you can’t detect frogs then you
can’t protect them.”
By Annalise Klingbeil, Calgary Herald July 30, 2012
CALGARY — Sporting breathable chest waders and armed with a GPS device,
endangered species population ecologist Lea Randall will spend the next six
weeks crawling in and out of bogs, ponds and marshes across southern Alberta.
Her mission: to count every frog she can find.
The ecologist will carry tools including a stopwatch and oxygen meter as
she seeks frog habitats, collects water samples and records the abundance of
northern leopard frogs across a 90,000-square-kilometre area south of Drumheller.
Randall recently embarked on six weeks of summer field research as part
of a study launched in 2009 by the Calgary Zoo’s Centre for Conservation
Research.
Through intensive fieldwork and mathematical modelling, the six-year
project aims to gain a better understanding of northern leopard frog population
dynamics.
The handsome and charismatic spotted amphibian, which can grow to the
size of a human fist, is considered a threatened species in Alberta and an
endangered species in B.C., said Randall.
The study and accompanying field research comes at a time when frog and
toad populations in Alberta and around the globe are decreasing.
“It’s a worldwide phenomenon . . . the decline of amphibians has been
noted on all continents on which amphibians occur,” said Anthony Russell, a
professor of zoology at the University of Calgary.
Over the past two decades in Alberta, the number of leopard frogs and
Canadian toads have diminished drastically, he said. “It’s very, very
noticeable”
While there are still three years left in the extensive northern leopard
study, early research shows neither a decrease nor increase in the population
of the species.
“So far our preliminary data suggests that the populations have at least
stabilized,” said Randall. “So, we don’t see evidence of decline, but we also
don’t really see any strong evidence that there’s been species recovery during
the period of our study.”
Leopard frogs can be difficult to detect in some habitats. In addition
to examining population dynamics, the study aims to improve monitoring
techniques.
“If you can’t detect frogs then you can’t protect them,” Randall said.
She said researching the frogs is important because Alberta has so few
amphibians. “If even one species goes extinct, we will have lost basically a
10th of our diversity in Alberta.”
Amphibians are a good indicator of ecosystem health, and as frogs and
toad numbers decrease, fish and insect species may also be affected.
“People have advocated that amphibians act a bit like the canary in the
coal mine. Whatever is affecting them now, as those changes become more drastic
and abundant, they will affect other things,” Russell said.
Kris Kendell, a senior biologist with the Alberta Conservation
Association, is the co-ordinator of the Alberta Volunteer Amphibian Monitoring
Program, which encourages “an army of citizen scientists” to submit their
observations.
Kendell said while some frog species in Alberta are stable, others
appear sensitive to human impact.
“The decline for the species that have suffered losses in numbers and
populations is mostly due to habitat — habitat loss and habitat degradation,”
Kendell said.
As the population and development in the province increases, there will
be increasing pressure on a species that is part of Alberta’s heritage, Kendell
said.
“On the most intrinsic level, amphibians are a part of Alberta’s natural
heritage,” Kendell said. “A lot of people’s first experiences with nature and
wildlife involve catching frogs or toads at their local slough or wetland (and)
hearing their voices in the springtime singing. They enrich our lives in ways
that are difficult to measure.”
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