A project to help Western chorus frog populations

The Western chorus frog is a small, endangered frog in Quebec and Canada. From 2004 to 2009, 30 per cent of their breeding sites in the Outaouais region were destroyed, mainly due to urban development. What’s more, only 25 per cent of known populations of chorus frogs in this region are considered viable and likely to survive in the long term. Other populations are under threat from habitat loss and degradation.

Experts carry out acoustic inventories to assess the health and size of the population. These acoustic inventories showed a decrease in the intensity of the Western chorus frog’s calls from 2005 to 2007. For that reason, a study aimed at restoring the habitat of chorus frogs is currently being carried out on land belonging to Ducks Unlimited Canada (DUC), as well as on land belonging to the city of Gatineau, south of Parc du Lac-Beauchamp.

Dispersal

Western chorus frogs need shallow, temporary ponds for breeding. They use a terrestrial habitat of around 200-250 metres around their breeding sites to feed, hide and hibernate. Therefore, connectivity between ponds is essential to encourage movement and safeguard the survival of the species (see diagram below).

The more ponds there are, the greater the population’s chances of survival: if one pond dries up, the others help to maintain the population. Connecting ponds therefore increases the species’ ability to cope with natural variations. With this in mind, our study explores solutions to improve connectivity between populations. This study is conducted by DUC, with the support of the city of Gatineau.

Inventories

In the spring, DUC team members scoured the area to update population data and identify potential new breeding sites. This led to the discovery of two new breeding grounds.

To help guide development recommendations, near-surface piezometers were installed to collect hydrological data. This will help us understand how ponds react to rain precipitation and to assess their capacity to retain water during the breeding season.

Environmental site characterization 

An environmental site characterization was also carried out to identify the types of habitat present as well as the flora and fauna that inhabit them.

The study should be completed this year. This will provide us with insights, allowing us to identify possible areas of intervention and prioritize ecosystem-friendly initiatives. The data will be used to assess measures to support tree frog reproduction and, by extension, contribute to the conservation of existing wetlands.

This work is supported by Environment and Climate Change Canada through the Initiative québécoise pour la protection et la restauration de l’habitat de la rainette faux-grillon de l’Ouest en Montérégie et en Outaouais, led by Nature-Action Québec, and is part of the Accélérer la conservation dans le sud du Québec (ACSQ) project for which the Nature Conservancy of Canada received funding from the gouvernement du Québec.