Each spring, male frogs and toads of the 13 species (11 frogs and two toads) found in Ontario sing a song to attract a mate (and you thought only birds could sing!). Each species has a unique song and specific temperature, and time during the spring that you hear them. They actually share the calendar, so they are not competing for audio time in the wild.
The first two species we hear, typically in April, when daytime temperatures reach a balmy 5 degrees Celsius, are the Wood Frog and the Spring Peeper. The Wood Frog sounds like a duck quacking and the Spring Peeper sounds like sleigh bells. When all the frogs sing together, scientists refer to this as a 'chorus'.
The males travel to breeding ponds after they wake up from their hibernation in local wetlands and start singing. The females take their time, playing hard to get, but also delaying the risk that predators may lay in wait for them. The female enters the wetland, typically around the edges where the water is shallow and cover is provided by the vegetation, again, trying to avoid predators, and finds a suitable mate. The male fertilizes her eggs right in the pond, and you can be sure they will not be practicing safe social distancing, even with COVID-19! The eggs will hatch later—each species has its own timeframe—and become what most people know as a tadpole.
Central Lake Ontario Conservation's Wildlife Biologist, Jackie Scott, was out this week monitoring amphibians in swamps and wetlands along our watershed roads, recording the species' calling and estimating the number of frogs singing. Monitoring this spring has started earlier than in past years and the Covid-19 isolation measures have made for ideal conditions in terms of listening for calling frogs from roadsides. Frogs are susceptible to road mortality at this time of year, particularly on rainy nights as they move to breeding ponds, and the generally reduced traffic volume right now may benefit frogs.
Jackie will head back to those sights later on and record other frog species singing as the temperatures warm up. Listen to this recording she captured in Whitby, just north of Brooklin (Highway 12 and Brawley Rd). Can you determine from the two frog song descriptions above which species she heard?
For more information about frog monitoring and how you can help frogs in your local community, check out http://www.torontozoo.com/adoptapond/frogs.asp for identification sheets, frog call recordings and more information about Frogwatch, a citizen science monitoring program available to residents across Ontario.