Recognizing the sounds in Rouge Park

Both pursuits are important ways people can add to knowledge about wildlife in the park and how well species are surviving on the edges of the city.

Frogs, with their permeable skin and sensitivity to pollution, are a good gauge of local water quality, and naturalists who have built small wetlands in the park want to see how many species have moved in.

The annual Rouge Park Frogwatch holds an orientation session next Wednesday, April 13, at the Toronto Zoo. Participants from past years are especially urged to attend the 6 p.m. meeting (for which people can reserve a space at www.surveymonkey.com/s/frogwatch2011rvsp).

The watch itself takes place on three nights - April 20, May 18 and June 22 - because different frog species emerge at different times each year. Each frog call is a distinct sound, measured at each spot from a single frog up to a "chorus" of at least three.

In 2010, a dry year, only six species were heard, but the previous spring there were nine, said Sheryl Santos, the park's stewardship co-ordinator.

Unfortunately, many frogs and other creatures crossing roads in the park each spring end up as roadkill.

This is especially true around the beginning of May when amphibians and reptiles tend to move from winter hibernation spots, said Mandy Karch, co-ordinator of the Ontario Road Ecology Group at the Toronto Zoo.

Karch said if more people knew wildlife crossings were so common, they would be more careful driving through the park, staying off their phones and paying particular attention when passing woodlots, wetlands and farm fields that can shelter wildlife.

"A mass amphibian movement will occur after a dry spell on a warm wet evening," she said last week. "With mass movement where there's vehicle traffic comes mass mortality."

For the second year, Karch's group wants volunteers to record what they find on certain stretches on road in the park - sometimes footprints or scat but more often evidence of "wildlife road interactions," meaning the remains of amphibians and other animals.

The recorded information could one day help the park to build special fences guiding wildlife to culverts, allowing species to avoid the most dangerous crossings. "The more volunteers we have, the more areas we can cover," Karch said.

The road study group, funded by the Rouge Alliance partnership that runs the park, has its orientation meeting at 10 a.m. Sunday, April 17 in zoo's administration office. Anyone interested can contact mkarch@torontozoo.ca or call 416-393-6365.