Pacific Treefrog / Pacific Chorus Frog (Pseudacris regilla / Pseudacris hypochondriaca)
Order Anura, Family Hylidae (Treefrogs), Genus Pseudacris (Chorus Frogs), Species Pseudacris regilla / hypochondriaca. Hylids are characterized by expanded adhesive toe pads for climbing and slender, agile body forms.
Species
Pacific Treefrog / Pacific Chorus Frog (Pseudacris regilla / Pseudacris hypochondriaca)
Family
Order Anura, Family Hylidae (Treefrogs), Genus Pseudacris (Chorus Frogs), Species Pseudacris regilla / hypochondriaca. Hylids are characterized by expanded adhesive toe pads for climbing and slender, agile body forms.
Size
Adult snout-vent length (SVL) ranges from 1.9 to 5.0 cm (0.75 to 2.0 inches). Females are generally larger than males. Weight typically ranges between 1 to 5 grams.
Conservation
IUCN status: Least Concern. Populations are generally stable and abundant across their range due to high adaptability to human-altered landscapes.
Description
A charming and remarkably adaptable small treefrog of western North America. Identified by its striking dark mask across the eyes and bright green or tan body, this vocal amphibian is a iconic herald of spring rains across forests and backyard gardens alike.
Key Features
1) Dark brown or black eye mask running from nostril through eye to shoulder. 2) Expanded adhesive toe discs. 3) Color variable from bright green to brown. 4) Small size under 2 inches.
Physical Description
Small, slender-to-slightly robust treefrog with a rounded snout, moderate-sized eyes with horizontal oval pupils, and expanded, sticky toe pads on fore and hind limbs. Limbs are relatively long, adapted for both jumping and climbing vertical surfaces.
Skin Texture & Coloration
Skin is slightly granular to smooth. Dorsal coloration is highly variable, ranging from vibrant lime green to bronze, tan, or brown, often changing depending on temperature and humidity. A distinctive dark brown or black mask or eye stripe runs from the nostril through the eye to the shoulder. Underside is pale cream to whitish.
Distinguishing Features
The most defining diagnostic feature is the dark brown or black stripe running from the tip of the snout through the eye to the shoulder ('eye mask'). Expanded toe pads and variable green-to-brown coloration further distinguish it.
Habitat
Highly adaptable across diverse habitats including temperate rainforests, oak woodlands, chaparral, grasslands, pastures, subalpine meadows, and suburban backyards or siding. Microhabitat includes moist vegetation, rocks, and artificial structures near ponds, streams, or ditches.
Geographic Range
Native to western North America, extending from southern Alaska and British Columbia south through Washington, Oregon, California, Nevada, Idaho, and into Baja California, Mexico.
Behavior
Primarily nocturnal or crepuscular, though active on overcast days. Capable of climbing walls, fences, and foliage using toe pads. When threatened, it leaps swiftly into dense cover or water.
Diet & Feeding
Insectivorous sit-and-wait predator feeding on small invertebrates including flies, beetles, ants, spiders, mites, and moths. Tadpoles feed on algae, detritus, and organic debris.
Reproduction
Breeds from early winter to late spring depending on latitude and rainfall. Males congregate around ponds, flooded fields, or slow streams to call females. Eggs are laid in small, gelatinous clusters attached to submerged vegetation.
Vocalizations
A loud, high-pitched two-tone 'ribbit' or 'creek-eeek' advertisement call. Chorus calls from multiple males can be deafeningly loud relative to their tiny size. Famous as the classic Hollywood background frog sound.
Life Cycle
Eggs hatch in 1 to 3 weeks depending on water temperature. The aquatic tadpole stage lasts 2 to 3 months before undergoing metamorphosis into juvenile froglets. Reaches sexual maturity in 1 to 2 years.
Conservation Status
IUCN status: Least Concern. Populations are generally stable and abundant across their range due to high adaptability to human-altered landscapes.
Toxicity & Defense
Non-toxic to humans. Produces mild skin secretions to deter small predators and prevent desiccation. Relies primarily on camouflage, hiding, and rapid jumping for self-defense.
Ecological Role
Serves as an essential mid-level link in the food web—controlling insect populations while providing a key food source for garter snakes, herons, egrets, mammals, and fish.
Similar Species
Boreal Chorus Frog (Pseudacris maculata) has three dark stripes down the back rather than a prominent single eye mask. Sierran Treefrog and Northern Pacific Treefrog are closely related genetic splits from P. regilla with nearly identical physical appearances.
Observation Tips
Listen for their distinctive loud choruses near shallow water bodies on wet spring nights. Search damp foliage, outdoor walls, porch light fixtures, or garden plants after dark using a flashlight.
Handling & Safety
Safe to observe closely. Direct handling should be minimized; if necessary, wash hands to remove lotions, oils, or soaps before touching, or use clean wet hands to avoid drying out their delicate permeable skin.
Seasonal Activity
Active from winter through autumn in coastal areas; enters brumation during cold winter months in high altitudes or northern ranges, or aestivates during severe summer dry spells.
Cultural Significance
Designated as the official state amphibian of Washington in 2007. Well known in popular culture due to its ubiquitous presence in film sound design.
Interesting Facts
The vocalization of the Pacific Treefrog is the standard 'ribbit' sound effect used in almost all Hollywood movies and television shows, regardless of where the scene is set geographically.