The Pacific Chorus Frog (Pseudacris regilla)

Photograph of a young Pacific Chorus Frog
Photograph by C. Bingham

     The Pacific Chrous Frog (also called the Pacific Treefrog) is the most common and the loudest frog in our region. In British Columbia it is found in the southern third of the province and on Vancouver Island and the Gulf Islands. It has been introduced into the Queen Charlotte Islands. Its range extends south to southern Arizona and Baja California.

Photograph of a Pacific Chorus Frog
Photograph by S. Price

  • Adult Pacific Chorus Frogs are 2 to 5 cm long

  • The colour varies from bright green to bronze to brown, as well as shades in between. These frogs can change the colour of their skin depending on the temperature and humidity.

  • A dark eye stripe runs from the tip of the nose to the shoulder.

  • The tip of each toe has a round, sticky toe-pad. Small webs are present between the toes of the hind feet.

  • The belly is white and unmarked.

  • The skin on the back is smooth and there are no folds or ridges. The skin on the belly is granular and there is a fold of skin across the breast between the front legs.

Habits: Pacific Chorus Frogs are found in a variety of habitats from pristine mountainous areas to farmland. Adult Chorus Frogs move to shallow pools and ponds to breed in early spring but will wander away into the woods to forage among low bushes and trees for insects.

The round pads at the tips of their toes stick to minute irregularities, enabling these frogs to climb almost any surface. A waxy coating on their skin prevents dehydration when the frogs are in dry conditions.

A Pacific Chorus Frog's toes
Photograph by S. Price
A Pacific Chorus Frog sitting in flowers
Photograph by C. Bingham

Pacific Chrous Frogs are unique among our frogs in that they can change their colour by contracting or expanding pigment cells in their skin. The colour changes are related to temperature and humidity rather than the colour of the background.


Breeding: Pacific Chorus Frogs gather in almost any sized body of water in early spring. The male mating call acts both as a territorial call and as an advertisement to attract females. The two-note mating call is repeated continuously and amplified by the large, round vocal sac inflated beneath the chin. This makes the call astonishingly loud for so small an animal.

Listen!

 The call of a single male Pacific Chorus Frog.    (Recorded by D. Green)

 A chorus of singing Pacific Chorus Frogs.    (Recorded at Pease Lake, Victoria, BC.)


Seduced by this beautiful serenade the female lays her eggs under water, usually attaching them to underwater vegetation. The eggmass is small (less than 4 cm), and round, and the eggs are enclosed in a thin layer of jelly. There can be anywhere from 12 to 60 eggs in each eggmass.

Pacific Chorus Frog egg mass
Photograph by S. Price

Pacific Chorus Frog tadpole
Photograph by S. Price

The tadpoles are greenish grey and flecked with gold markings. They metamorphose into tiny frogs by early summer. They will be ready to breed in a couple of years.





A newly metamorphosed Pacific Chorus Frog
Photograph by S. Price

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Webpage written and maintained by Purnima Govindarajulu and Mike Dodd
email: bcfrogwatch@victoria1.gov.bc.ca
Last updated May 2008