Boreal Chorus Frog Calling

Boreal chorus frog songs are an excellent first sign of spring’s arrival. Once the outside temperatures reach approximately 50 degrees Fahrenheit, the boreal chorus frogs emerge from their winter slumber in the ice or frozen earth. Males use a vocal sac to call in early spring. This call serves many purposes. They will use their call to establish territory, find the perfect mate, and make themselves known. Their call can be distinguished by a “cree” that sounds similar to someone running their finger across a fine-toothed comb. Just 18 days after mating, small tadpoles emerge from the fertilized eggs. These tadpoles will grow and develop into adult frogs that are ¾ to 1 ½ inches long. This frog was observed in April 2023. 

• What drives different frogs to call at different times of the year?

• What do you think drives the frogs to wake up?
• Why is it beneficial for some frogs to emerge before others?
• Why is it beneficial to emerge so early?
• Why do only the males call?

Students could:

• Use their senses at a specific site to listen and record the abundance of frogs.
• Research the emerging times of other frogs, and create a sound timeline of emerging frogs/toads.
• Create a story of the life cycle of a boreal chorus frog.

• University of Nebraska-Lincoln | Boreal Chorus Frog: Describes habitat, diet, and physical characteristics of the Boreal Chorus Frog.
• University of Minnesota | Boreal Chorus Frog: Includes progression and timeline of mating and incubation periods.
• Iowa Department of Natural Resource | Frog and Toad Calls: Descriptions and recordings of Iowa’s native frogs, their calls, and their range across the state.