CHS Blog

Join the Chorus: Volunteers Needed to Monitor Northern Limit of Western Chorus Frog Range

April 02, 2020
Siobhan Galway and Monique Aarts, Blazing Star Environmental

With the arrival of spring, western chorus frogs (WCF) have started calling from their breeding wetlands within southwestern Ontario! For the past two years Blazing Star Environmental has partnered with Canadian Wildlife Service and Trent University to create a volunteer-based, long-term, range-wide monitoring program for the WCF in Ontario. We are excited to announce that this program has officially launched!

Western Chorus Frog
Photo: Scott Gillingwater

But why put in such a large-scale effort for such a little frog?

For a little background info, the WCF is a small frog that grows to be about 2.5 cm long. It can be recognized by 3 broken dark vertical stripes down its back and a distinctive white stripe on its upper lip. However, you are most likely to recognize this frog by its breeding call, which sounds like a finger running down the teeth of a comb! The WCF ranges throughout southern Ontario, north to Huntsville and east into Quebec (grey shading on map).

The range of the Western Chorus Frog in Canada, as it was described in the 2008 COSEWIC Status Report on the Western Chorus Frog (Pseudacris triseriata), Carolinian Population and Great Lakes/St. Lawrence — Canadian Shield Population, in Canada. However, recent evidence suggests that the populations in Quebec and eastern Ontario are actually Boreal Chorus Frog (Pseudacris maculata), and work is ongoing to update the range of these two species in Canada.

Importantly however, frogs are an indicator species for their environment and are important to Ontario’s biodiversity. They absorb water through their permeable skin and are therefore sensitive to water quality and the health of their habitat. Unfortunately, the WCF (Great Lakes / St. Lawrence - Canadian Shield population) is listed as threatened in Canada due to ongoing population decline. The 2015 Recovery Strategy for the Western Chorus Frog (Pseudacris triseriata), Great Lakes / St. Lawrence — Canadian Shield population, in Canada outlined the threats faced by this species, which include habitat degradation, pollution, invasive species, and disease.

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Western Chorus Frog
Photo: Scott Gillingwater

Chorus frogs breed in temporary wetlands or flooded fields that lack fish and dry up later in the summer. This specialized habitat is shared with few other frog species — and is not a primary target for large-scale frog monitoring programs, which target more generalized frog habitat. Therefore, there are still many unknowns about the species, including its distribution. More information, including assessments of trends in the species’ distribution over time, is needed to protect the WCF across their range, and the new species-specific long-term monitoring program will collect this much-needed information. Data gathered will inform recovery efforts and allow the conservation community to quickly detect and respond to population declines over time.

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An example of the small, shallow habitats used for breeding by Western Chorus Frog.
Photo: Monique Aarts

Surveying for WCF poses challenges because the range is large and the calling season is short. While Blazing Star Environmental is determined, our team is small. The success of this program depends on the participation of dedicated and passionate volunteers across the Ontario range of the WCF. We have recruited hundreds of volunteers to conduct surveys across the range. However, we are currently lacking volunteers in the northern extent of their range (see brown shading on the following map).

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Areas where additional surveyors are required (brown shading) for the new long-term Western Chorus Frog monitoring program.

Volunteers need only choose the number of sites they wish to survey, the distance they are willing to travel, and to conduct 5-minute auditory surveys 2-3 times during the calling period (March — early June). If you are located in the program gap areas, Blazing Star Environmental invites you to join the chorus this spring by volunteering with the WCF long-term monitoring program! For more information about volunteering with the program, including important COVID-19 measures, email info@blazingstar.ca