Returning the Leopard Frog to the Columbia Wetlands

Many of the older residents of the valley will remember catching and playing with frogs as a kid, herein the valley. That is not something kids growing up now can do, at least with Leopard Frogs. The northern leopard frog was historically widespread in the Columbia wetlands. In the 1970’s and 1980’s, however, the leopard frog declined throughout its historic range in western North America and disappeared from the Columbia Wetlands, as a result, it seems, of a fungus infection called Chytridiomycosis.

Many of the older residents of the valley will remember catching and playing with frogs as a kid, herein the valley. That is not something kids growing up now can do, at least with Leopard Frogs. The northern leopard frog was historically widespread in the Columbia wetlands.  In the 1970’s and 1980’s, however, the leopard frog declined throughout its historic range in western North America and disappeared from the Columbia Wetlands, as a result, it seems, of a fungus infection called Chytridiomycosis.

Despite numerous surveys, the Leopard Frog is now found in only one place in the Kootenays, the wetlands at the Creston Valley Wildlife Management Area. The populations in the Okanagan, in the Columbia Wetlands and in wetlands in the south end of the East Kootenay seem to have completely disappeared.

As a result, the “Rocky Mountain Population” of northern leopard frog, has been designated  as “Endangered” by the Committee on the Status of Endangered Wildlife in Canada. The Northern Leopard Frog Recovery Team was established a few years ago to address the problems associated with the recovery of the northern leopard frog.

One of the means by which they hope to do this is through a reintroduction program, with the goal of re-establishing populations throughout the historic range of the species.  This program was initiated between 2001 and 2005, when 10,147 leopard frog tadpoles and 14,487 young frogs were released in Creston and at Bummer’s Flats, a wetland just north of Cranbrook (south of Wasa Lake)  and was funded primarily by the Fish and Wildlife Compensation Program. Results to date appear encouraging, as the species is still present and reproducing at Bummer’s Flats, five years after the last reintroduction. So we now have, we hope, two populations surviving in the Kootenays. The next obvious location for establishing another population is in the Columbia Wetlands.

The Columbia Wetland Stewardship Partners, working with Penny Ohanjanian, a local biologist and member of the recovery team, with assistance from Chris Carli and Dr. Suzanne Bayley of the University of Alberta have been working over the last year to determine the feasibility of reintroducing northern leopard frogs to the Columbia Wetlands. The restoration of these frogs to this extensive area would greatly benefit not only this species but also the biodiversity of the Columbia Valley.  (The Leopard Frog is one of two species that have been lost, over time, in this system. The other is Columbia River Chinook Salmon that spawned in this reach of the river prior to 1942.

This project had two elements. One was to attempt to locate any leopard frogs that still occurred naturally in the Columbia Wetlands. Twenty-seven calling surveys were carried out in May and June of this year, but no frogs were heard. So it is fair to assume that no natural populations occur.

The second element of the project was a survey to identify specific wetlands where leopard frogs could be introduced and would be likely to survive. Leopard frogs require a mix of different habitats, which they use at different times of the year. In spring they move from wintering habitat to breeding ponds where they lay their eggs in shallow water. These ponds generally have abundant submergent vegetation (plants growing in the water), and must retain water throughout the summer for the tadpoles to develop into young froglets.  When they do so, they tend to remain in the water and on land along the margins of the breeding pond.

After breeding, adult frogs forage both at the edges of ponds and in adjacent, moist uplands or meadows.  Vegetation in these uplands should be preferably less than 30 cm high and must not be so dense that it impedes movement.  Deeper water in which to escape should also be available nearby.  In fall, northern leopard frogs require transitional habitat to allow them to travel to their over-wintering areas.  The transitional habitat may include water bodies, ditches and stretches of agricultural land over which they can travel. They then over-winter at the bottom of rivers, springs and lakes. These water bodies must not freeze to the bottom and must be well oxygenated.  At Creston, dissolved oxygen (DO) values at the wintering habitat ranged from 10.5 to 12.2 parts per million.  These seasonal habitats should be in fairly close proximity to each other, generally within a 2 km radius.

Penny and her team used these various parameters to identify wetland areas that have all of these attributes and could potentially support leopard frogs. They first identified 20 likely areas, using aerial photos and Google Earth, that appeared to provide the mix of habitats required. They then assessed marsh health by collecting data on water quality and sediment chemistry at the potential reintroduction sites.  Data was then compared with samples taken from known leopard frog breeding ponds at Creston and Bummer’s Flats. Of the 20 water bodies initially examined, 7 were identified as potential reintroduction sites. A pond near Edgewater was included as a potential reintroduction site as it supported leopard frogs in 1967, when four specimens were collected for the National Museum in Ottawa. The sites identified were all south of  Spillimacheen, as indicated in the map below. Other sites north of Spillimacheen may be looked at in the future.

The plan is to submit their report to the Recovery Team and request tadpoles and young froglets from Creston to re-introduce at some or all of these sites in the near future. This assessment project was carried out with funding support from the Columbia Valley Local Conservation Fund, the University of Alberta, and the Columbia Basin Trust Environmental Initiatives Fund. Congratulations to Penny and her team on leading the way on this recovery project.