The voice that fills the forest is a tiny frog with powerful lungs

The arrival of spring in North America comes with the shrill call of a tiny brown frog that fills the night air. They gather around ponds and utter a high-pitched mating call that can be heard for miles. In chorus with other frogs, their call is one of the loudest sounds that can be heard. Often disguised or hidden in leaves and brush, they are hard to spot. This spring peeper was found at the edge of a vernal pool in Ontario, Canada, just days after the snow and ice melted. These frogs have a glucose cryoprotectant that helps them form an antifreeze in their blood. They enter a dormant state to survive winter, emerging in the spring to feed and mate. The throat sac of the peeper expands and helps it make such a loud sound. The louder the call, the more attractive the frog will seem to a female that will answer the call. Often, male frogs with smaller voices will position themselves near a very loud male, intercepting the arriving females.