Boreal chorus frog © Sam Brinkler
There are two chorus frog species in Ontario: the boreal (Pseudacris maculata) and the western chorus frog. Prior to 1989, they were considered to be one species. Like many species in the treefrog family, they are more often heard than seen.
Characteristics
The boreal chorus frog is small and smooth skinned, and varies in colour from green-grey to brown. A dark stripe runs through the eye and a white stripe along the upper lip. This species is distinguished from most other treefrogs by the three dark stripes down the back. In some individuals, the stripes are broken into dashes or dots. Adults grow to three centimetres in body length. The breeding call of this species resembles the sound made by running a fingernail along the teeth of a comb.
Boreal chorus frog © Sam Brinkler
Similar Species
The western chorus frog is almost identical to the boreal chorus frog but has shorter hind legs. These two frogs are best distinguished by their call or location; in Ontario, their distributions do not overlap. Their calls are very similar, but in the call of the western chorus frog, the pulse rate is longer and slower.
Boreal chorus frog © Joe Crowley
Habitat
The boreal chorus frog inhabits forest openings around woodland ponds but may be found in the vicinity of any body of non-flowing water. This frog breeds in almost any fishless pond with at least 10 centimetres of water, including splash pools, roadside ditches, flooded fields, beaver ponds, marshes, swamps, shallow lakes and other water bodies with little or no current, often those lacking tree cover. The boreal chorus frog overwinters on upland sites near water, usually under logs or underground.
View an interactive map of the known ranges of boreal chorus frogs in Ontario.
Biology
Boreal chorus frogs breed very early in the spring, calling day and night, often before the winter ice has completely melted. The female lays 150 to 800 eggs in clusters of five to 100 eggs, which are attached to submerged vegetation. The eggs hatch within a few weeks, and the tadpoles finish transforming by about two months. Following metamorphosis, they usually mature in one to two years and live two to three years, rarely up to six years. Chorus frogs can survive being frozen and are among the first frogs to emerge in the spring. They feed on small insects and other invertebrates, and are eaten by a wide variety of predators.
Other names: Pseudacris nigrita septentrionalis, Chorophilus septentrionalis
Boreal chorus frog © Joe Crowley
Threats and Trends
Habitat loss and degradation are threats to any given local population of the boreal chorus frog, but no major threats affect this species as a whole, and it is not believed to be in any significant decline.
Boreal chorus frog © Scott Gillingwater
Current Status and Protection
Neither the Committee on the Status of Species at Risk in Ontario nor the Committee on the Status of Endangered Wildlife in Canada has assessed the status of the boreal chorus frog. The species has no protection under the Ontario Fish and Wildlife Conservation Act. The International Union for Conservation of Nature lists the global status of the boreal chorus frog as Least Concern. The species’ status was confirmed in December 2020.
Learn more about reptile and amphibian conservation and what you can do to help these species on our Reptile and Amphibian Stewardship page.
Boreal chorus frog © Sam Brinkler
What You Can Do
- Report a sighting
- Get involved in reptile and amphibian conservation on your property, on the road and in your community
- Donate to support reptile and amphibian conservation
- Watch for reptiles and amphibians on the road
- Don’t release pet reptiles and amphibians into the wild
- Read more about the boreal chorus frog in the Ontario Reptile and Amphibians Atlas publication.
Boreal chorus frog © Joe Crowley