Pacific Chorus Frog or Pacific Treefrog (Pseudacris regilla)
Order Anura, Family Hylidae (Treefrogs), Genus Pseudacris. This species is part of the chorus frog genus, which are typically small, slender treefrogs known for their distinctive calls.
Species
Pacific Chorus Frog or Pacific Treefrog (Pseudacris regilla)
Family
Order Anura, Family Hylidae (Treefrogs), Genus Pseudacris. This species is part of the chorus frog genus, which are typically small, slender treefrogs known for their distinctive calls.
Size
A small frog, adults typically measure between 2.5 to 5 cm (1 to 2 inches) in snout-to-vent length (SVL). Females are generally slightly larger than males.
Conservation
IUCN Status: Least Concern. Populations are generally stable and widespread, though they face local threats from habitat loss, pollution, and the spread of the chytrid fungus.
Description
The Pacific Chorus Frog is the quintessential sound of the West Coast night. Small enough to fit on a thumb, this resilient amphibian is often the first to begin calling in the spring, its 'ribbit' echoing through rainy suburban yards and remote mountain lakes alike. Its remarkable ability to change color from leafy green to earthy brown allows it to vanish against almost any background.
Key Features
Dark stripe (mask) through the eye; small toe pads; variable green or brown body color with darker spots; small size (under 2 inches).
Physical Description
A small, slender frog with a rounded snout and large, prominent eyes. It possesses small but distinct toe pads (circular discs) and limited webbing between the toes. The tympanum (eardrum) is visible but smaller than the eye.
Skin Texture & Coloration
The skin is generally smooth but can appear slightly granular. Coloration is highly variable, ranging from shades of green to brown, tan, gray, or reddish-brown. It often displays dark, irregular spots or blotches on the back and a characteristic dark 'eye mask' stripe extending from the snout through the eye to the shoulder.
Distinguishing Features
The most diagnostic feature is the dark brown or black mask extending from the nostrils through the eye to the shoulder. They also often have a dark Y-shaped mark between the eyes, and their ability to change color from light to dark based on environment is notable.
Habitat
Highly adaptable; found in forests, meadows, grasslands, and suburban gardens. They require slow-moving or still water like ponds, seasonal pools, or roadside ditches for breeding but are mostly terrestrial during the rest of the year.
Geographic Range
Common along the Pacific coast of North America, from British Columbia, Canada, south through Washington, Oregon, and California into Baja California, Mexico, extending eastward into Montana and Nevada.
Behavior
Primarily nocturnal but can be active during the day in moist conditions. They are excellent climbers due to their toe pads but spend much of their time on the ground or in low vegetation. They are known to 'play dead' or remain motionless to avoid detection.
Diet & Feeding
Active foragers that consume a wide variety of small invertebrates including flies, beetles, ants, spiders, and leafhoppers. Tadpoles are herbivorous, grazing on algae and detritus.
Reproduction
Breeding occurs from early winter to early summer depending on latitude. Males gather at water sources and produce loud choruses to attract females. Eggs are laid in small, jelly-like clusters attached to underwater vegetation.
Vocalizations
The most famous frog call in the world: a high-pitched, two-part 'ribbit' or 'krick-ek'. Due to Hollywood sound libraries, this specific call is often used in movies regardless of the film's geographic setting.
Life Cycle
Metamorphosis from egg to tadpole to froglet usually takes 2 to 3 months. In the wild, they typically live for 2 to 5 years. They reach sexual maturity within one year.
Conservation Status
IUCN Status: Least Concern. Populations are generally stable and widespread, though they face local threats from habitat loss, pollution, and the spread of the chytrid fungus.
Toxicity & Defense
Not toxic to humans. They rely on cryptic coloration (camouflage), their ability to change shades to blend in, and their small size to hide from predators like garter snakes and birds.
Ecological Role
They serve as a vital link in the food chain, controlling insect populations and serving as a primary food source for snakes, birds, and small mammals. They are excellent indicators of water quality and wetland health.
Similar Species
The Baja California Treefrog (Pseudacris hypochondriaca) and Sierran Treefrog (Pseudacris sierra) are nearly identical and were formerly considered the same species (the P. regilla complex). Identification usually depends on geographic location.
Observation Tips
Listen for their loud choruses on rainy nights in early spring. Follow the sound to shallow pools and use a flashlight to scan low vegetation or the water’s edge. They are easily found in residential areas with lush gardens.
Handling & Safety
Safe to handle briefly with wet hands, but skin oils and soaps can harm their permeable skin. Always wash hands after handling to prevent the spread of salmonella or irritating your eyes with their skin secretions.
Seasonal Activity
Highly active during the rainy season for breeding. In colder or drier months, they may go into a period of dormancy (brumation) in underground burrows or under leaf litter.
Cultural Significance
Because their 'ribbit' was recorded for early Hollywood films, it has become the 'universal' frog sound in global pop culture, appearing in movies set in deserts, jungles, and even other planets.
Interesting Facts
Despite being called 'treefrogs', they are more ground-dwelling than many other members of the Hylidae family. They are the official state amphibian of Washington and Oregon.