Monday, September 19, 2005

Green Frog

(click to expand)

One of my favourite places to visit is the Don Valley Brick Works. I was there today to work on a pet project - a survey of flowering plants. The survey is a personal project. I thought it would be good to create an inventory of species in the quarry ponds. To do a proper inventory you need to visit at least three times of the year, once each during spring, summer, and fall. So far I have completed the summer and fall surveys. Without going into too much detail, I have catalogued about 70 species of which 28 are non-native. Of these 12 are considered invasive. At least there are more natives than non-natives - a good sign?

While doing the survey I came across this little guy sitting on a stone at the edge of a pond. He was nice enough to let me take a few pictures including the one displayed here. This is a Green Frog (Rana clamitans). It is one of two common species found in the Don. The other is the American Toad (Bufo americanus). Both species have managed to adapt to the urban environment. They can often be found hibernating in backyards. Other species need a less disturbed habitat so you won't find them in the Don. Both the Green Frog and the American Toad have been seen at the Brick Works.

I happen to know this is a male frog. This can be determined by looking at the large brown circle behind the eye. This is the eardrum. If the circle is noticeably larger than the eye, it is male; if it is about the same size it is a female. Green Frogs are more often heard than seen. The mating call is a single low-pitched twang, sounds like 'galamp' or 'galumph'.

The Metro Zoo has a website called Adopt-A-Pond and it is a good source for information on pond dwelling creatures, including the Green Frog. If you visit this site you can hear a recorded sound of their voice.

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