Mountain chorus frog
Pseudacris brachyphona

Chorus frogs, both the mountain and western species, are small treefrogs similar in size to cricket frogs, less than 35 mm in length, with little webbing between the toes. The mountain chorus frog is a terrestrial species often found some distance from water on wooded hills and in forested valleys in unglaciated southeastern Ohio.

Fig. 10. Mountain chorus frog

The mountain chorus frog is light to dark brown in ground color and has a dark triangle between the eyes (Fig. 10). A dark stripe extends back from the snout through the eye and along the side nearly to the back legs.

In addition, there are two broken or uninterrupted stripes resembling reversed parentheses coursing down the back. If the reversed parentheses meet across the back, an X-shaped pattern is formed that closely resembles that of a spring peeper. The digital discs of chorus frogs are small, and both species are poor climbers, seldom venturing more than 30 cm above ground into the vegetation. As with many species of treefrogs, females average larger in total length than males. Males have a yellowish wash on the throat that is overlaid with gray stippling. The throat of the female is white.

• A dark stripe extends back from the snout of the mountain chorus frog through the eye and along the side nearly to the back legs.

• Two broken or uninterrupted stripes resembling reversed parentheses course down the brown back, and there usually is a dark triangle between the eyes.

The breeding season extends from mid-March through late May in Ohio. Loose egg masses of 10-60 eggs are laid attached to branches or other vegetation below the surface in valley pools or slow flowing streams. Each female may lay 900-1200 eggs, each 1.6 mm in diameter when laid, but reaching 7 mm when the protective layers are fully swollen. They hatch in as little as three to five days intosmall larvae 4-5 mm long. Larval development is rapid and only 52-65 days are required for development from the egg to completion of transformation.

The insect-like call of the mountain chorus frog is a rapid, nasal sounding trill that increases in frequency over the duration of the call (Fig. 11).

	Fig. 11. Call of the mountain chorus frog

Call of the mountain chorus frog (17 seconds, 137 KB)
Excerpt (3 seconds, 30 KB)
A chorus of mountain chorus frogs (18 seconds, 143 KB)

• The call of the mountain chorus frog is a rapid, nasal sounding trill that increases in frequency throughout the duration of the call.
• The dominant frequency of the call in the spectrogram is about 2350 Hz, and the call duration is 0.3 seconds.