Boreal Chorus Frog
This chorus frog can be found across Colorado from low valleys to high mountains.
About This Species
Dark stripe on side of body extends from snout to groin; color of upper side variable—green, brown, reddish, or reddish and green, with green or brown stripes or spots; hind toes not distinctly webbed. Mature male: throat skin loose and yellowish or dark during breeding season; expanded vocal sac evenly rounded or slightly flattened.
More Information:
Physical Characteristics
Head and body length up to about 37 mm (1.5 inches).
Range
Nearly statewide, from low river valleys to high mountains, but scarce or absent in most of southeastern Colorado. Common in many areas.
Habitat
Vicinity of wet meadows, marshes, ponds, and lakes.
Reproduction
Breeding Call
A stuttering “preeep” that ascends in pitch.
Larvae
Upper side olive to blackish; tail fin tall, strongly arched, finely stippled or squiggled with brown; eyes at outside margin of head when viewed from above; gut more or less visible through pale golden belly skin; usually 2 rows of tiny teeth on upper lip, 3 rows on lower lip; up to about 52 mm (2 inches) long.
Eggs
Deposited on vegetation in loose, irregular, or elongated clusters of several to more than 150.
Life History
Breeds in waters lacking a strong current, especially among submerged plant material, mainly April-June in lowland areas and mostly May-June in the mountains. Calling often occurs before and after these periods. Larvae metamorphose into small frogs as early as early June in lowland areas and as late as September in the mountains.