Pacific chorus frog

Pacific chorus frog
Name	Pacific chorus frog
Status	LC
Status system	IUCN3.1
Taxon	Pseudacris regilla
Authority	(Baird and Girard, 1852)

Pacific chorus frog is a small, widespread anuran found along the western coast of North America. It is notable for its variable coloration, vocalizations, and role in freshwater wetland communities. Researchers from institutions such as the Smithsonian Institution, University of California, Berkeley, University of Washington, Stanford University, and British Columbia natural history programs have studied its ecology, distribution, and genetics.

Taxonomy and Naming

Described by Spencer Fullerton Baird and Charles Frédéric Girard in 1852, the species was historically placed in the genus Hyla before revision to Pseudacris. Taxonomic work by researchers at the Museum of Comparative Zoology and analyses using methods from the American Museum of Natural History and molecular laboratories at University of California, Los Angeles have clarified relationships among chorus frogs. Debates in the Journal of Herpetology and proceedings of the Society for the Study of Amphibians and Reptiles have addressed cryptic diversity, with comparisons to related taxa described from regions such as Oregon, Washington (state), California, and British Columbia. The specific epithet derives from Latinized forms used in 19th-century North American herpetological surveys.

Description

Adults typically measure 2 to 5 cm in snout–vent length; males are generally smaller than females. Field guides produced by the National Park Service, Canadian Wildlife Service, and regional naturalist clubs document a dorsum ranging from brown to green with a distinctive dark dorsal stripe or three dorsal stripes in some populations. Tympanum size, toe webbing, and limb proportions are diagnostic characters used in keys published by the American Museum of Natural History and the California Academy of Sciences. Morphological variation has been illustrated in monographs from the Museum of Vertebrate Zoology and in pictorial treatments appearing in the Encyclopaedia Britannica and regional atlases.

Distribution and Habitat

The species occurs from British Columbia through California and inland to parts of Idaho and Nevada, occupying coastal forests, montane meadows, agricultural margins, and urban ponds. Distributional records are maintained by organizations such as the Integrated Taxonomic Information System, the Global Biodiversity Information Facility, and provincial databases of Environment and Climate Change Canada. Habitats include ephemeral and permanent wetlands associated with watersheds governed by river systems like the Columbia River, Sacramento River, and coastal estuaries. Conservation planning documents from the U.S. Fish and Wildlife Service and provincial agencies often treat breeding habitat connectivity in regional assessments.

Behavior and Ecology

Pacific chorus frogs are primarily nocturnal and crepuscular, with males producing trilling advertisement calls used in choruses during the breeding season; acoustic studies published in the Journal of the Acoustical Society of America and presented at meetings of the Acoustical Society of America have quantified call structure. Diet consists of small arthropods, with foraging ecology examined by teams at the University of British Columbia and the Oregon State University through gut-content and isotope studies. Predators include birds monitored by the Audubon Society, small mammals surveyed by the Museum of Vertebrate Zoology, and fish evaluated in reports by the California Department of Fish and Wildlife. Role in food webs and disease dynamics has been investigated in work associated with the Centers for Disease Control and Prevention and university veterinary programs addressing chytridiomycosis.

Reproduction and Life Cycle

Breeding typically occurs in late winter to spring in ponds and ephemeral pools; timing varies with latitude and elevation, as documented by regional herpetological surveys from the California Herpetological Society and the Washington Department of Fish and Wildlife. Males form choruses and engage in amplexus; eggs are laid in clumps attached to submerged vegetation, with embryo development subjected to studies at the Scripps Institution of Oceanography and university developmental biology labs. Larval tadpoles undergo metamorphosis over weeks to months depending on temperature and hydroperiod; life-history parameters have been modeled in publications from the National Science Foundation–funded projects and graduate research at the University of California, Davis.

Conservation and Threats

The species is currently assessed as Least Concern by international evaluators, yet local declines have been recorded in studies commissioned by the U.S. Geological Survey, provincial conservation agencies, and nongovernmental organizations such as the Nature Conservancy. Threats include wetland drainage documented in environmental impact assessments for projects authorized under laws administered by the U.S. Environmental Protection Agency and provincial regulators, invasive predators noted in fisheries reports by the California Department of Fish and Wildlife, pollutant exposure examined by researchers at the Environmental Protection Agency, and emerging infectious diseases studied by the World Organisation for Animal Health. Conservation actions promoted by entities such as the National Park Service, Canadian Wildlife Service, and local land trusts include wetland restoration, monitoring programs coordinated with the Amphibian Survival Alliance, and public education initiatives in partnership with universities and museums.

Category:Chorus frogs Category:Amphibians of North America