Chorus Frogs in Hiding

by Carl Strang

This year the early songs of western chorus frogs at Mayslake Forest Preserve are coming mainly from locations inland from the water’s edge at the stream corridor marsh, their biggest breeding area. I don’t know if this represents a change in behavior, or whether I simply had failed to notice it in the past. Most of the little guys seem to be singing within clumps of brown grasses and sedges, usually within a few feet of the water’s edge. Last week I was able to get a partial peek at one which had chosen a slightly more exposed spot.

In the exact center of this photo is a tiny puddle of water, about 4 inches across, between the two sticks. Whenever the frog sang, the water in the puddle vibrated, giving him away.

I was able to get close enough to see his exact location under the smaller stick.

Can you see the little highlight in the stick’s shadow?

Unfortunately for me, the bigger stick blocked my view and prevented me from holding the camera at a low enough angle to see more than the tiniest part of the frog.

This expanded part of the previous photo shows the yellow edge of the frog’s bag-like expanded throat.

After a few days last week when dozens of frogs sang, nearly all have gone quiet. They barely had started, and I can’t believe they have finished already. I find myself attributing the many bizarre things I am observing on the preserve to the abnormally warm, dry weather. The main pool of the stream corridor marsh has shrunk slightly, and this week the tiny puddle shown in the photos is gone. Chorus frogs breed in temporary pools. Their tadpoles develop fast, but need to have those pools last a few weeks. The marsh will be there for them, but they don’t know that and I suspect that some cue is telling them to wait. If I am right, a period of rain and/or cooler temperatures should get them going again.

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