Abundance of northern leopard frogs is a good sign for the species in Manitoba
Leopard frog (Photo courtesy of Peter Kelly and rare Charitable Research Reserve)
The northern leopard frog might be one of the most widespread leopard frogs in North America, but in Canada's Prairie provinces, it is a species of special concern.
This species needs three different habitats to sustain itself and complete its life cycle. To reproduce, it relies on pristine wetlands to mate and lay its eggs in. In the summer, it forages on terrestrial lands, including uplands and native prairie. For overwintering, the northern leopard frog seeks out water bodies that do not freeze to the bottom.
Once abundant enough to be commercially harvested, populations started to dwindle in Manitoba due to the spread of an apparent illness that killed large numbers of these frogs.
But in the 1900s, this small but mighty frog started making a comeback, with local populations recovering significantly.
Few reports on surveys of northern leopard frogs are available in Manitoba, but the Nature Conservancy of Canada (NCC) has recently published their findings from a small survey conducted in the Riding Mountain Natural Area. The natural area contains most of Manitoba's remaining fescue prairie, in addition to wildflowers, aspen parkland, loamy wetlands, highland evergreens and lowland eastern hardwood forest.
While conducting vegetation surveys on September 8, 2011, NCC Manitoba staff Cary Hamel, Julie Pelc, and Levi Newediuk noticed an exceptionally high volume of what they believed to be young-of-the-year northern leopard frogs on a portion of NCC's 632-hectare (1,562-acre) Riding Mountain House property.
None of the surveyors had previously observed such a high concentration of frogs despite combined decades of field experience. In an effort to attempt to quantify this amazing natural phenomenon, the team set out to conduct a survey of northern leopard frogs on the property. The survey consisted of six sections across the upland areas of the property, roughly 100 to 145 metres long and perpendicular to Wargatie Lake. Walking along the designated areas, NCC staff counted how many northern leopard frogs they saw flushing on either side of the survey area.
In total, 442 northern leopard frogs were counted along the six survey areas. While the sample size was small, this observation contributes information available about this species in Manitoba. Nearly one frog was observed for each square metre surveyed. This suggests that in the year of the survey, these conservation lands may have supported several thousand individuals of this species of concern. This is great news for the conservation of this species!
You can read more about the project in an article published in the journal Blue Jay here.