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NAS - Nonindigenous Aquatic Species

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Pseudacris regilla   (Baird and Girard, 1852)

Common Name: Northern Pacific Chorus Frog

Synonyms and Other Names: Taxonomy: available through

Identification: Pseudacris regilla is a small hylid (treefrog) with a SVL (snout-vent length) of 19-50 mm (0.75-2 in) and small toe pads (disks) (Stebbins, 2003). The dorsal coloration of these color-changing, sometimes mottled, frogs also varies genetically:  green, reddish, tan, gray, brown, or black, but typically green or shades of brown (Leonard et al., 1993; Stebbins, 2003). A black or brown eyestripe is often present (Powell et al., 1998; Stebbins, 2003). Distinct morphological criteria for distinguishing P. regilla from its sister species the Sierran chorus frog, Pseudacris sierra, have not yet been established. See the species account titled “Pseudacris sierra (Jameson, Mackey, and Richmond, 1966)” on this website. The northern Pacific chorus frog’s call is a stereotypical, loud, two-part “krec-ek” or “ribbit” that is probably nearly identical to the call of P. sierra.  The tadpoles of P. regilla are light greenish gray or olive brown, have high tail fins, and the internal viscera can be seen ventrally (Stebbins, 2003; Gregory and Campbell, 1984).

Northern Pacific chorus frogs have been illustrated by a variety of authorities (Test, 1898; Wright and Wright, 1949; Stebbins, 1985, 2003; Smith, 1978; Behler and King, 1979; Nussbaum et al., 1983; Cook, 1984; Gregory and Campbell, 1984; Kricher, 1993; Leonard et al., 1993; Beltz, 2005). 

Size: SVL is 19-50 mm.

Native Range: Pseudacris regilla is indigenous to Pacific and western regions of North America, from southern and western British Columbia (including Vancouver Island and smaller offshore islands), Canada, southward through Washington, and western Oregon (Test, 1898; Stebbins, 1954, 2003; Jameson et al., 1966; Campbell et al., 1982; Nussbaum et al., 1983; Cook, 1984; Gregory and Campbell, 1984; Leonard et al., 1993; Lamar, 1997; Duellman and Sweet, 1999; Ripplinger and Wagner, 2004; Recuero et al., 2006a; Dornburg and Weaver, 2007).