The call of the American Toad(Bufo americanus) is a long trill. a>

The female gray treefrog will select a male based on the quality of his song, and move closer and initiate mating (amplexus). The eggs will hatch, and the the gray treefrog tadpoles will develop for a couple months as tadpoles, before they metamorphose and leave the pond.

The two photos below show the same male Gray Treefrog, and were taken moments apart. The top photo shows him in the middle of his advertisement call; his vocal sac is inflated and you can see ripples in the water caused by his trill vibrating through his body. The bottom photo shows him between calls. There is no disturbance in the water. His vocal sac is still partially inflated, but it is not nearly as full as during his call.

I liked this photo so much that I turned it into coloring page that you can print out and color in with your kids. You can find a printable copy on my coloring pages site.