Spring Peepers (Pseudacris crucifer) are small frogs with big voices. In early spring, these rarely seen, insect-eaters sound off en masse (though I've heard individuals vocalize in every month of the year, including the occasional sunny winter day). Both male and female peepers gather in wetlands, many of which only hold water in spring, but it's the males who announce the coming green season with their chorusing. Guided by their calls and those of Wood Frogs who often share the same breeding season habitat, species of Salamanders join the party, as they all seek to ensure future generations of moist-skinned amphibians.
Roads pose a potentially fatal obstacle to creatures journeying to these springtime gatherings. I escorted the above Spring Peeper, presumably on his or her way to a nearby wetland, off of a wet road early one warm morning in mid-March, but many other frogs had waited out winter only to be killed on the same roadway. So, if you can, please don't drive on warm, rainy nights in late February through early April, and instead walk to a wetland near you and enjoy the sounds of the season.
Want more? Animal Diversity Web has a comprehensive species account which includes identification, behavior, and life cycle info, along with many photos. For a look-back on a wetland-focused Moon Challenge that I did when I lived in Massachusetts, see my Wetland Loop Recap.