Here's a video clip of a male Spring Peeper calling, with another nearby, probably a female. The male really puts his whole body into the effort of calling - hopefully the female peeper was impressed!
And another short clip of a peeper calling - this one looked like he waved at me!
Peepers were the only frog we heard calling, but I did spot one very sleepy Bullfrog (Rana catesbeiana) poking her head up. Spring Peepers spend the winter in the forest, burrowed underground. They actually have an anti-freeze-like substance in their bodies that prevents them from suffering damage from sub-freezing temperatures. Bullfrogs, on the other hand, spend the winter under the ice of the pond, hibernating in the leaves and muck at the bottom. Because of the cold temperatures their energy needs are very low, and they can take in enough oxygen through their skin to sustain them.I could tell this Bullfrog was a girl because her tympanum, or ear, the little circle just beneath her eye, is smaller than the eye. On a male Bullfrog the tympanum is larger than the eye. This doesn't work for Spring Peepers, but you can still tell the males apart by the yellowish or dark brown deflated vocal sac on their throats, while females have white throats.