Boreal Chorus Frog (Pseudacris maculata)
by Jeff LeClere
Boreal chorus frog, Pseudacris maculata, calling.
A valid fishing license is required to possess this species for bait or food. Commonly heard, though rarely seen, little frogs that are found throughout Iowa. Iowa populations were formerly called western chorus frog, Pseudacris triseriata.
These tiny frogs are probably Iowa’s smallest frogs with a body length of slightly over an inch. The ground color may be varying shades of brown, gray, olive or reddish. There are three relatively wide, longitudinal stripes down the back. These may be broken. The stripes are brown, rusty or greenish. The belly is plain light brown or white. There is a stripe from the snout through the nostril and eye and continues down the side to the groin. The body is long and slender compared to the short legs. The toe pads are very tiny.
There are no recognized subspecies of the boreal chorus frog, Pseudacris maculata.
The boreal chorus frog is found statewide.
The boreal chorus frog is found in a variety of habitats, but never far from woodlands. They breed in temporary pools of water to large wetlands and even in shallow parts of lakes. Unlike some other species of amphibians, this frog can survive in urban areas.
Chorus frogs begin seasonal activity in March or early April, and immediately begin calling and breeding. The call sounds like a pprrreeep similar to a chirping cricket or running a thumbnail down the teeth of a fine toothed comb. Most breeding activity is done by the end of May, but individuals may be heard giving their advertisement call anytime from March to November, especially in evening or after rains.
Chorus frogs lay small clusters of eggs. I have seen freshly laid chorus frogs eggs in a flooded pasture on April 4 in Allamakee County. The tadpoles metamorphose in about 2-2 1/2 months. Chorus frogs do not move far from their wetlands during the summer, especially in urban environments. They apparently overwinter under rocks or logs, using glucose to withstand most freezing temperatures.
Boreal chorus frogs feed on small invertebrates. They may hunt in low shrubs but due to their short limbs, they do not climb very high and they are not quite as acrobatic as other treefrogs.