If you live anywhere in the eastern half of North America, you've probably heard the sound of Spring Peepers (Pseudacris crucifer), which are known for their springtime chorus - not their voyeuristic tendencies. They are tiny frogs that loudly call near shallow pools in the spring.
To know when they will become active, use the thermal sum starting from February 1st with an offset of 3° C. Take the average temperature each day in Celsius (sum high and low then divide by 2) and subtract 3. If the number is less than 0, ignore it, but if positive add it to the value of all previous days going back to February 1. When the total gets to 44, the Peepers should wake up. Here in central Pennsylvania that was on March 11 this year.
