Frogs are Fantastic
Today is both the first day of spring and World Frog Day! Let’s celebrate the change of season by learning more about our froggy friends.
The Credit River Watershed is home to 10 species of frogs and toads. As you explore our parks this spring, count how many frog species you can spot.
Toad or Frog?
If all toads are frogs, but not all frogs are toads, how can we tell the difference?
Simply put, toads are a type of frog. An easy way to tell if you are looking at a toad or frog is by examining their skin.
Frogs typically have smooth, mucus-covered skin compared to toads who have dry, bumpy and rough skin.
Another clue to tell if you are looking at a toad or a frog is by their location. Because frogs need to upkeep their moist, glistening skin, they’re usually found in or near water. Most species breed in fresh water too and a cluster of eggs floating on the surface of a pond or attached to a water plant may be a sign that a frog is nearby.
Many toad species do not need to be near a body of water because their skin is better at retaining the moisture it needs. If there is not water nearby, you’re most likely looking at a toad.
An example of a difficult-to-identify species is the gray treefrog (Hyla versicolor). This species is the perfect trick question because they share toads warty-like skin and live away from water but are in fact, frogs.
Hopping Through the Watershed
Ontario is home to 12 frog and toad species and 10 of those live in the Credit River Watershed.
Frog populations are important indicators of wetland health in our watershed. Monitoring frog populations, which thrive in both aquatic and terrestrial habitats, provides valuable insights into overall watershed health.
Here are four watershed species and their colourful characteristics that can help identify them:
Green Frog
The green frog, often confused with other species, is one of the most commonly seen frog species in the watershed.
The green frog (Lithobates clamitans) is a larger species with distinct tympani or eardrums and two prominent dorsolateral ridges, folds of skin that run partly down the back. Frogs’ dorsolateral ridges are a great way to tell species apart.
The most efficient way to tell frogs apart is by their call. Learning the sounds each species makes can help you easily identify them, even without seeing them up close.
This species’ call is either a single “gunk” sound, like a loose banjo string, or a more complex call with several less vigorous repetitions of “GUNK, gunk-gunk-gunk”.
When statuesque and silent, you can tell it’s a green frog by its typically green upper lip, large eardrums and the prominent ridges running halfway along its upper back.
Their bellies are white with darker lines or spots, sometimes with a yellow tinge. Green frogs’ back legs have dark stripes and sometimes spots on the back.
Males have a bright yellow throat and tympani that are noticeably larger than the eye.
Pickerel Frog
The pickerel frog (Lithobates palustris) is medium-sized with smooth, pale brown skin and prominent bronze dorsolateral ridges.
Pickerel frogs are often confused with the more common leopard frog (Lithobates pipiens), but the pickerel frog has two distinct rows of square or rectangular spots running down the back while the leopard frog has round or oval spots in a more random pattern.
If you are still unsure, peek at the underside of the frog. A pickerel frog has a bright yellow groin, whereas the leopard frog lacks this colourful underside.
If you hear snoring while out on a hike, it’s probably not someone taking a nap in the trees, but most likely a pickerel frog call. Their call sounds like a low nasal snore or somewhat like the mooing of a cow.
If the human-like call doesn’t scare off predators, their poisonous skin will! Pickerel frogs secrete toxins through their skin that can irritate or kill other animals and could irritate human skin.
Mink Frog
The mink frog (Lithobates septentrionalis) gets its name for its stunning stink. They emit a musky, mink-like odour when handled or threatened to defend themselves.
Mink frogs are medium-sized, come in shades of olive green to brown, have yellow bellies and sometimes have dark spots or mottling on their sides and hind legs.
They are commonly confused with green frogs. Unlike green frogs, mink frogs lack visible dorsolateral ridges and have spots or blotches on their hind legs, not dark bands.
They’re an aquatic species and will only be spotted within bodies of water. Their tadpoles take several years to develop, so mink frogs only breed in permanent ponds that do not dry up.
Did you know a large chorus of mink frogs sounds like popcorn popping? Their call has a rapid series of three or more croaks, which sound like the tapping of a metal hammer on wood.
Spring Peeper
Spring peepers (Pseudacris crucifer) are another common watershed species.
This tiny frog is light brown with an easily recognizable darker X-shaped marking on the back. They’re the only frog in Ontario with this shape marking their identity.
One cute fact is that adults grow to only four centimetres in length, that’s about the width of a golf ball.
Their name is a key factor in recognizing a spring peeper as their call is a single, loud, high-pitched peep that repeats over and over. A full chorus can be deafening up close and can be heard over a kilometre away.
Frog Monitoring Stations in the Watershed
Frogs are excellent indicators of ecosystem health because they are sensitive to changes in their environment. Monitoring wetland communities helps us understand how our ecosystems are responding to stressors like habitat loss, invasive species and climate change. Learn how we monitor frog communities at 30 wetland sites throughout the Credit River Watershed.
Find Frogs at our Parks
You can help protect frogs by:
- Reporting sightings and contributing to community science on iNaturalist.
- Creating habitat for reptiles and amphibians on your property and getting involved in your community.
- Watching for wildlife on the road.
- Not releasing pet reptiles and amphibians into the wild.
Embrace the beginning of spring with a visit to our parks. You can share your first of the season sightings with us on Instagram, Facebook and X.
By Sarah Lebret, Associate, Marketing and Communications.