Pacific Treefrog (Pseudacris regilla)
Order Anura, Family Hylidae, Genus Pseudacris, Species regilla. Members of the Hylidae family are typically known as treefrogs, characterized by their sticky toe pads and arboreal or semi-arboreal lifestyles.
Species
Pacific Treefrog (Pseudacris regilla)
Family
Order Anura, Family Hylidae, Genus Pseudacris, Species regilla. Members of the Hylidae family are typically known as treefrogs, characterized by their sticky toe pads and arboreal or semi-arboreal lifestyles.
Size
Adults typically measure between 1.9 to 5 cm (0.75 to 2 inches) in snout-to-vent length (SVL). Females are generally slightly larger and heavier than males. They are lightweight, weighing only a few grams.
Conservation
IUCN Status: Least Concern. Populations are stable and widespread, though they remain sensitive to habitat fragmentation and water pollution.
Description
The quintessential 'ribit' frog of the West Coast. These small, charismatic amphibians are the first signs of spring for many, filling the night air with their loud, rhythmic songs. They are masters of disguise, shifting their skin tone to blend perfectly with moss or dry leaves.
Key Features
Black 'eye mask' stripe, small toe pads, often a triangular or 'Y' mark on top of the head, and highly variable brown-to-green coloration.
Physical Description
Small, slender frogs with a somewhat flattened body. They have a distinct dark mask or 'eye stripe' that extends through the eye to the shoulder. Their heads are relatively broad with large, gold-rimmed eyes and horizontal pupils. Limbs are short but powerful, ending in small but visible toe pads.
Skin Texture & Coloration
Skin is generally smooth but can be slightly granular. Coloration is highly variable; individuals can be shades of green, brown, tan, reddish, or gray. They often exhibit irregular dark blotches or spots on the back. A key feature is their ability to change lightness or darkness over a few minutes to match surroundings. No warning coloration is present.
Distinguishing Features
The most diagnostic marker is the dark 'eye mask' or 'Zorro mask' that runs from the nostril through the eye to the shoulder. They have small toe pads (smaller than many other Hylids) and lack the extensive webbing of aquatic frogs. A dark 'Y' or 'V' shape is often visible between the eyes.
Habitat
Extremely versatile; found in forests, grasslands, chaparral, and even suburban gardens. They prefer areas near quiet water like ponds, streams, or seasonal pools for breeding but are frequently found in damp leaf litter, low vegetation, or under rocks and logs.
Geographic Range
Common across the Pacific coast of North America, ranging from British Columbia, Canada, through Washington, Oregon, and California, and reaching as far east as Montana and Nevada.
Behavior
Primarily nocturnal, though active during the day in the breeding season. They are exceptional climbers despite their small size. When threatened, they often crouch low and rely on camouflage or make quick, erratic leaps to reach shallow water or dense cover.
Diet & Feeding
Insectivorous. Adults consume spiders, beetles, flies, ants, and leafhoppers. They are 'sit-and-wait' predators that use their sticky tongues to capture prey. Tadpoles are herbivorous, grazing on algae and detritus.
Reproduction
Breeding occurs from late winter to early summer, triggered by rain. Males migrate to water and form loud choruses. Amplexus is axillary. Eggs are laid in small, jelly-like clusters of 10-70, attached to underwater vegetation. No parental care is provided after egg-laying.
Vocalizations
Highly recognizable 'rib-it' or 'kree-eck' call. It is a two-note sequence with a rising inflection. During choruses, the sound can be deafening. This specific call is famous in Hollywood, often used for background 'jungle' or 'woods' sounds regardless of global location.
Life Cycle
Eggs hatch in 1-3 weeks. Tadpoles are dark brown with gold flecking and take about 2-3 months to reach metamorphosis. Juveniles are tiny (less than 1cm) upon leaving the water and reach sexual maturity within one year. Lifespan in the wild is often 2-5 years.
Conservation Status
IUCN Status: Least Concern. Populations are stable and widespread, though they remain sensitive to habitat fragmentation and water pollution.
Toxicity & Defense
Non-toxic to humans and most predators. Their primary defense is camouflage (crypsis) and jumping. Their skin secretions are mild and intended only to keep their skin moist.
Ecological Role
Critical mid-level link in the food web. They control insect populations and serve as a primary food source for snakes, birds (like herons), and small mammals.
Similar Species
Boreal Chorus Frog (Pseudacris maculata) which has three longitudinal stripes rather than blotches; Baja California Treefrog (Pseudacris hypochondriaca) which is very similar but occupies more southern reaches.
Observation Tips
Look for them on rainy nights or near backyard ponds during spring. Using a flashlight at night can reveal their eyeshine. Listen for the distinct two-note call to locate breeding sites.
Handling & Safety
Safe to handle, but always wet your hands first as dry palms can damage their delicate, absorbent skin. Avoid handling if you have recently applied sunscreen or bug spray. Always wash hands afterward to prevent salmonella transmission.
Seasonal Activity
Active year-round in milder coastal climates. In colder regions, they may brumate underground or in deep leaf litter during freezing temperatures, emerging with the first heavy rains of late winter.
Cultural Significance
Commonly featured in nature documentaries and local folklore of the Pacific Northwest as a herald of the rainy season. It is the official state amphibian of Washington.
Interesting Facts
Despite being called 'treefrogs', they are more often found on the ground or in low shrubs than high in trees. Their call is the standard 'night sound' in cinema history, even in movies set in the Amazon or Africa.
Notes
What kind of frog is this?