Adults attain a snout-vent length of 36mm in males and 45mm in females. This species has short slender arms, slender unwebbed fingers, small digital discs, and toes that are long, slender and 3/4 webbed. Dorsal surface is tuberculate, ventral surface is smooth to granular. Dorsal coloration is gray to brown with dark brown to green spots. Ventral coloration is dull grey to white on the throat and belly, and pale yellow on the groin, thigh, ventral surface of shank, and inner surface of the tarsus. There is a white line on the upper lip.
See another account at californiaherps.com.
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (20,000-200,000 square km (about 8000-80,000 square miles)) Range extends from southwestern California south into northern Baja California Norte, Mexico. Elevational range extends from near sea level to about 2,290 meters (7,500 feet) (Stebbins 1985).
Distribution and Habitat
Found in southwestern California and northwestern Baja California, Mexico; in the mountains and canyons from San Luis Obispo, California to Bahia de los Angeles, Baja California. This species occurs from the costal canyons east to the western edge of the Mojave and Colorado deserts. Found in elevations from near sea level to 1700m. Often found in riparian habitats.
Length: 5 cm
Catalog Number: USNM 3230
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Locality: Tejon Pass, Kern, California, United States, North America
Sierra Madre Oriental Pine-oak Forests Habitat
This taxon is found in the Sierra Madre Oriental pine-oak forests, which exhibit a very diverse community of endemic and specialized species of plants, mammals, reptiles and amphibians. These high mountains run north to south, beginning in the USA and ending in Mexico. The Sierra Madre Oriental pine-oak forests are a highly disjunctive ecoregion, owing to the fact that they are present only at higher elevations, within a region with considerable expanses of lower elevation desert floor.
The climate is temperate humid on the northeastern slope, and temperate sub-humid on the western slope and highest portions of the mountain range. Pine-oak forest habitat covers most of the region, even though most of the primary forest has been destroyed or degraded. However, the wettest portions house a community of cloud forests that constitute the northernmost patches of this vegetation in Mexico. The forests grow on soils derived from volcanic rocks that have a high content of organic matter. The soils of lower elevations are derived from sedimentary rocks, and some of them are formed purely of limestone. In the northernmost portions of the ecoregion, the forests occur on irregular hummocks that constitute biological "islands" of temperate forest in the middle of the Chihuahuan Desert. To the south, from Nuevo León southward until Guanajuato and Queretaro, the ecoregion is more continuous along the mainstem of the Sierra Madre Oriental.
Dominant tree species include the pines: the endemic Nelson's Pine (Pinus nelsonii), Mexican Pinyon (P. cembroides), Smooth-bark Mexican Pine (P. pseudostrobus), and Arizona Pine (P. arizonica); and the oaks Quercus castanea and Q. affinis. In mesic environments, the most common species are P. cembroides, and Alligator Juniper (Juniperus deppeana), but in more xeric environments on the west slopes of the mountains, the endemic P. pinceana is more abundant. Gregg's Pine (P. greggii) and Jelecote Pine (P. patula) are endemic.
Many mammalian species wander these rugged hills. Mule Deer (Odocoileus hemionus), Puma (Puma concolor), Cliff Chipmunk (Tamias dorsalis), Collared Peccary (Tayassu tajacu), Coati (Nasua narica), Jaguar (Panthera onca) and Coyote (Canis latrans) are a few of the many diverse mammals that inhabit this ecoregion. Some threatened mammals found in the ecoregion are: Bolaños Woodrat (Neotoma palatina VU); Diminutive Woodrat (Nelsonia neotomodon NT), known chiefly from the western versant of the Sierra Madre; Chihuahuan Mouse (Peromyscus polius NT); and Mexican Long-nosed Bat (Leptonycteris nivalis EN).
A considerable number of reptilian taxa are found in the Sierra Madre Oriental pine-oak forests, including three endemic snakes: Ridgenose Rattlesnake (Crotalus willardi); Fox´s Mountain Meadow Snake (Adelophis foxi); and the Longtail Rattlesnake (Crotalus stejnegeri VU), restricted to the central Sierra Madre. An endemic skink occurring in the ecoregion is the Fair-headed Skink (Plestiodon callicephalus). The Striped Plateau Lizard (Sceloporus virgatus) is endemic to the ecoregion. The Sonoran Mud Turtle (Kinosternon sonoriense VU) is found in the ecoregion and ranges from southwestern New Mexico south to northwestern Chihuahua.
The following anuran taxa occur in the Sierra Madre Oriental pine-oak forests: Red-spotted Toad (Anaxyrus punctatus); Cane Toad (Rhinella marina); Elegant Narrow-mouthed Toad (Gastrophryne elegans); New Mexico Spadefoot Toad (Spea multiplicata); Sinaloa Toad (Incilius mazatlanensis); Pine Toad (Incilius occidentalis); Southwestern Toad (Anaxyrus microscaphus); Woodhouse's Toad (Anaxyrus woodhousii); Great Plains Narrowmouth Toad (Gastrophryne olivacea); Great Plains Toad (Anaxyrus cognatus); Plateau Toad (Anaxyrus compactilis); Texas Toad (Anaxyrus speciosus); Sonoran Desert Toad (Incilius alvarius), found only at lower ecoregion elevations here; Rana-ladrona Silbadora (Eleutherodactylus teretistes); Sabinal Frog (Leptodactylus melanonotus); Mexican Leaf Frog (Pachymedusa dacnicolor); Montezuma Leopard Frog (Lithobates montezumae); Yavapai Leopard Frog (Lithobates yavapaiensis); Northwest Mexico Leopard Frog (Lithobates magnaocularis); Bigfoot Leopard Frog (Lithobates megapoda), who generally breeds in permanent surface water bodies; Mexican Cascade Frog (Lithobates pustulosus); Tarahumara Frog (Lithobates tarahumarae VU); Western Barking Frog (Craugastor augusti); Lowland Burrowing Frog (Smilisca fodiens); Taylor's Barking Frog (Craugastor occidentalis); Blunt-toed Chirping Frog (Eleutherodactylus modestus VU), found only at the very lowest elevations of the ecoregion; Shiny Peeping Frog (Eleutherodactylus nitidus); California Chorus Frog (Pseudacris cadaverina); Rio Grande Frog (Lithobates berlandieri); Madrean Treefrog (Hyla eximia); Mexican Treefrog (Smilisca baudinii); Dwarf Mexican Treefrog (Tlalocohyla smithii); Canyon Treefrog (Hyla arenicolor); Northern Sheep Frog (Hypopachus variolosus); Chiricahua Leopard Frog (Lithobates chiricahuensis). There are three salamanders found in the ecoregion: the endemic Sacramento Mountains Salamander (Aneides hardii), found only in very high montane reaches above 2400 meters; Tiger Salamander (Ambystoma tigrinum); and the Tarahumara Salamander (Ambystoma rosaceum).
Sierra de la Laguna Pine-oak Forests Habitat
This taxon is found in the Sierra de la Laguna pine-oak forest, a mountainous ecoregion which rises from the arid Baja California Sur, creating islands of unique vegetative communities. There are approximately 694 plant species, approximately 85 of which are endemic to this ecoregion. Overall species richness is low to moderate, with a total of only 231 vertebrate taxa. The ecoregion is classified in the Tropical and Subtropical Coniferous Forests biome. Much of the pine-oak association remains intact due to the inaccessibility of the rugged and inaccessible terrain.
The topographical features and geological events that gave rise to this particular region are responsible for the diversity of climates and vegetation in the same area. The highest strata of mountains, situated at 1600 to 2000 metres (m) in elevation, are composed of pine-oak forests that transform into oak-pine forests (1200 m) and oak forests (800 m) as elevation decreases. The climate is temperate sub-humid with summer rains and occasional winter rains.
These pine-oak forests constitute the wettest portions in the state of Baja California Sur (760 millimetres of precipitation annually). Slight variations in climatic conditions make up three different vegetation assemblages in the temperate forest. Pine forests at the highest elevations are dominated by Pinus cembroides ssp. lagunae, and understory taxa such as Muhlenbergia spp. and Festuca spp. Pine-oak forests dominated by associations of Pinus cembroides subsp. lagunae with Quercus devia, Arbutus peninsularis, and Quercus tuberculata, and a variety of trees of smaller stature such as Calliandra peninsularis and Mimosa tricephala, with associated shrubs to complement the landscape.
Some of the endemic reptiles are the Southern Alligator Lizard (Elgaria multicarinata) and the Yucca Night Lizard (Xantusia vigilis). Other reptilian taxa found in the Sierra de la Laguna pine-oak forests include the Baja California Rock Lizard (Petrosaurus thalassinus), Baja California Rattlesnake (Crotalus enyo) and the Baja California Brush Lizard (Urosaurus nigricaudus).
Only two amphibian taxa are found in the Sierra de la Laguna pine-oak forests. The Red-spotted Toad (Anaxyrus punctatus) is one anuran found here. The widely distributed California Chorus Frog (Pseudacris cadaverina) is another resident of the ecoregion. One other anuran, Pseudacris regilla, was previously recognized in the ecoregion, but erecent DNA analysis has rendered this taxon of unclear distribution.
Of the approximately 30 mammalian species of mammals present, one of them (an endemic bat) lives only in pine-oak forests. The level of endemism is high, and this is well demonstrated by the proportion of endemic species with respect to total recorded species. More than ten percent of the mammalian species found at Sierra de la Laguna are endemic. One notable mammal found along the far west coast, including California and Baja, is the Ornate Shrew (Sorex ornatus). There are several threatened mammals found in the Sierra de la Laguna pine-oak forests, including: the Mexican Long-tongued Bat (Choeronycteris mexicana NT). The isolation of this region has contributed to the scarcity of predators, and to the poor competitive ability of some animals. Rodents and lagomorphs are virtually absent from the region
The avifauna inhabiting these pine-oak forests is important because half of the bird species breeding at Sierra de la Laguna only utilize pine-oak forests as breeding habitat. The endemic Baja Pygmy Owl (Glaucidium gnoma hoskinsii), along with the White-winged Dove (Zenaida asiatica) and Golden Eagle (Aquila chrysaetos) are only a few of the avian species found in this ecoregion. Other notable birds in this and the Gulf of California xeric scrub ecoregion include the Xantus's Hummingbird (Hylocharis xantusii) and the endangered Peninsular Yellowthroat (Geothlypis beldingi EN)..
Baja California Desert Habitat
This taxon is found in the Baja California Desert ecoregion, located on most of the western side of the Baja Peninsula, containing varied habitats such as mountains, plains and coastal dunes. This desert is one of the largest and best preserved in Mexico, and due to its isolation, contains a high level of species richness and endemism. A series of ophiolytes (formations of gabrum, ultramafic rocks, and volcanic lava) surround the most prominent orographic feature: The San Andres mountain range. Overall, the climate is arid with variable temperature. The isolated nature of the peninsula, and its proximity to the sea, maintains a measure of humidity, and creates a stable diurnal temperature.
The predominant vegetation associations are composed of xeric scrub, which have been subdivided in diverse categories according to dominant species and the ecological conditions in which they occur. Thick-stemmed trees and shrubs, growing on rocky volcanic soils, cover the highest parts of the mountain ranges. Dominant plant species are Ambrosia camphorata, Common Stork's-bill (Erodium cicutarium), and Astragalus prorifer. The Boojumtree (Fouquieria columnaris) can be also found at elevations up to 1200m. Many species of cacti are present. Dominant species within the Baja California Desert vary with elevation. Epiphytes such as Small Ballmoss (Tillandsia recurvata) and Cudbear (Rocella tinctoria) grow in low elevation, humid areas, and account for a majority of the perennial vegetation. Areas previously submerged under the sea (in the Miocene era) are now covered by highly saline and alkaline-tolerant species, such as Ambrosia magdalenae, El Vizcaino Agave (Agave vizcainoensis), Datilillo (Yucca valida), Pitaya Agria (Stenocereus gummosus), and Porter's Muhly (Muhlenbergia porteri). Dune vegetation includes Creosote Bush (Larrea tridentata), Barclay's Saltbush (Atriplex barclayana), Rush Milkweed (Asclepias subulata) and Nicolletia trifida.
There are a number of reptilian taxa found in the Baja California Desert including the endemic Baja California Brush Lizard (Urosaurus lahtelai). The Baja California Legless Lizard (Anniella geronimensis EN) is also endemic to the ecoregion, and is restricted to a narrow strip around 87 kilometres (km) long, ranging from about six km north of Colonia Guerrero, southerly to a point south of Punta Baja at the northern edge of Bahia El Rosario. This legless lizard extends to at most four km inland in the Arroyo Socorro, but otherwise found only in the coastal zone; A. geronimensis also occurs on Isla San Gerónimo. Also found here is the San Lucan Leaf-toed Gecko (Phyllodactylus unctus NT), a species not endemic to the ecoregion, but restricted to the southern Baja Peninsula and the Gulf of California islands of Partida Sur, Gallo, Espiritu Santo, Ballena, Gallina and Cerralvo.
There are only a few amphibians found in the ecoregion. Anuran taxa occurring here include: California Chorus Frog (Pseudacris cadaverina); Pacific Chorus Frog (Pseudacris regilla); and Canyon Treefrog (Hyla arenicolor). Also found here is the Plateau Toad (Anaxyrus compactilis), an endemic to the lower central Mexican Plateau and Baja California Desert; another toad occurring in the ecoregion is the Western Toad (Anaxyrus boreas NT). The Channel Islands Slender Salamander (Batrachoseps pacificus) was earlier thought to occur in this ecoregion, but genetic data shows that this taxon is strictly endemic to the Channel Islands of California.
Endemic mammals include San Quintín Kangaroo Rat (Dipodomys gravipes CR), and Baja California Rock Squirrel (Spermophilus atricapillus EN). Other mammals that are classified as special status are the Lesser Long-nosed Bat (Leptonycteris yerbabuenae VU). Some shallow coastal saltwater lagoons protruding into the Baja California Desert along the Pacific Ocean provide key breeding habitat for the Grey Whale (Eschrichtius robustus CR). One of the largest such breeding waters is the remote San Ignacio Lagoon, extending many kilometres inland and rarely exceeding fifteen metres in depth.
Important sites for avian conservation include the Ojo de Liebre lagoon, along the Pacific coast, which is home to millions of overwintering ducks and geese. Bird species in the Baja California Desert include such notable raptor taxa as Golden Eagle (Aquila chrysaetos), Peregrine Falcon (Falco peregrinus), Southern Crested Caracara (Caracara plancus), Osprey (Pandion haliaeutus), and Burrowing Owl (Athene cunicularia).
Habitat and Ecology
Comments: This species is found in rocky canyons near streams and washes with permanent pools. It requires some shade as it retreats to shaded rock crevices during the day. It ranges from desert and coastal stream-courses to the pine belt in the mountains (Stebbins 1985). It breeds in the quiet water of rocky streams. Eggs are attached to twigs or are loose on the bottom (Stebbins 1972).
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Comments: Adults feed on insects, spiders, and centipedes. Larvae probably eat algae, organic debris, and plant tissue.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 21 - 80
Comments: This species is represented by a large number of occurrences (subpopulations). Phillipsen and Metcalf (2009) mapped 46 locations across southern California from which specimens recently were collected.
10,000 - 100,000 individuals
Comments: Total adult population size is unknown but presumably exceeds 10,000.
Most individuals range over small portion of streamcourse; 83% of movements <25 m in 1-year study (Kay 1989).
Life History and Behavior
Comments: Inactive in cold temperatures and hot, dry weather. Primarily nocturnal except during the breeding season when it may be heard quacking day and night.
Breeds February-early October (Stebbins 1985). Lays eggs singly.
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N4 - Apparently Secure
NatureServe Conservation Status
Rounded Global Status Rank: G4 - Apparently Secure
Intrinsic Vulnerability: Moderately vulnerable
Environmental Specificity: Very narrow to narrow.
Global Short Term Trend: Relatively stable (=10% change)
Comments: Population trend is unknown but probably stable to slightly declining.
Global Long Term Trend: Increase of 10-25% to decline of 30%
Comments: Likely relatively stable in extent of occurrence, probably less than 25% decline in population size, area of occurrence, and number/condition of occurrences.
Life History, Abundance, Activity, and Special Behaviors
A stream-dwelling population in the San Gabriel mountains was observed to use deep crevices away from the stream to hibernate for the winter.
Degree of Threat: Unknown
Comments: The rugged habitat of this frog inhibits various kinds of habitat alterations that often occur in nearby relatively flat areas.
Under natural conditions, solar UV-B radiation reduces embryo survival; effects at the population level remain to be determined (Anzalone et al. 1998).
Ervin (2005) reported: "California treefrogs are difficult to find in presumably high-quality habitat where populations of non-native predatory fish have become established, suggesting that some populations may be experiencing declines (R. Fisher, personal communication; personal observations)." However, this species generally thrives in areas where frog breeding pools are relatively small and/or isolated and and not favorable for establishment of predatory fishes.
California tree frog
The California tree frog or California chorus frog (Pseudacris cadaverina) is a "true" tree frog (family Hylidae) from southern California (USA) and Baja California (Mexico). Until recently, the California tree frog was classified in the genus Hyla.
It is a cryptically colored species of tree frog, often resembling granitic stones. It is grey or light brown on its dorsum with darker blotches, and has a whitish venter. It is yellow on the undersides of its legs, groin, and lower abdomen; males of the species have a dusky-yellow throat. The California tree frog has conspicuous toe webbing and pads, and its dorsal skin is roughened and warty. It is 2.9–5 cm (1.1–2.0 in) long.
Habitat and conservation
This species is most likely to occur along streams with abundant boulders and cobbles in their channels. Its distribution is spotty and localized. These frogs are easily handled.
California tree frog is not considered threatened by IUCN: it is a relatively common species with broad distribution, and there are no major threats, except perhaps UV radiation that reduces embryonic survival.
- Geoffrey Hammerson, Georgina Santos-Barrera (2004). "Pseudacris cadaverina". IUCN Red List of Threatened Species. Version 2013.1. International Union for Conservation of Nature. Retrieved 18 September 2013.
- Frost, Darrel R. (2013). "Pseudacris cadaverina (Cope, 1866)". Amphibian Species of the World 5.6, an Online Reference. American Museum of Natural History. Retrieved 18 September 2013.
- Bradford Hollingsworth and Kathy Roberts. "Pseudacris cadaverina California Treefrog". SDHMN Field Guide. San Diego Natural History Museum. Retrieved 18 September 2013.
- Robert N. Fisher and Ted J. Case. "Pseudacris cadaverina California Treefrog". A Field Guide to the Reptiles and Amphibians of Coastal Southern California. United States Geological Survey (USGS). Retrieved 18 September 2013.
Names and Taxonomy
Comments: Formerly included in the genus Hyla; transferred to the genus Pseudacris by Hedges (1986), based on allozyme data (see also Highton 1991). Cocroft (1994) analyzed morphological and biochemical data and concluded that the Hyla regilla-Hyla cadaverina clade does not arise within the clade containing Pseudacris (traditional sense), P. ocularis, and P. crucifer; he suggested that the most conservative approach may be to leave regilla and cadaverina in the genus Hyla until their relationships are more clearly resolved. da Silva (1997) recommended that for now Hedges' (1986) definition of Pseudacris should be maintained.
A molecular phylogeny of Pseudacris based on mtDNA data (Moriarty and Cannatella 2004) revealed four strongly supported clades within Pseudacris: (1) A West Coast Clade containing regilla and cadaverina, (2) a Fat Frog Clade including ornata, streckeri, and illinoensis, (3) a Crucifer Clade consisting of crucifer and ocularis, and (4) a Trilling Frog Clade containing all other Pseudacris. Within the Trilling Frog Clade, brimleyi and brachyphona form the sister group to the Nigrita Clade: nigrita, feriarum, triseriata, kalmi, clarkii, and maculata. The Nigrita Clade shows geographic division into three clades: (1) populations of maculata and triseriata west of the Mississippi River and Canadian populations, (2) southeastern United States populations of feriarum and nigrita, and (3) northeastern United States populations of feriarum, kalmi, and triseriata. Current taxonomy does not reflect the phylogenetic relationships among populations of the Nigrita Clade (Moriarty and Canatella 2004). For example, the molecular data appear to indicate that triseriata, maculata, and clarkii in the western United States are conspecific, but the authors indicated that further sampling and analysis of the Trilling Frog Clade are needed before their relationships can be determined and an appropriate taxonomy established. Moriarty and Cannatella (2004) found that subspecific epithets for crucifer (crucifer and bartramiana) and nigrita (nigrita and verrucosa) are uninformative, and they therefore discouraged recognition of these subspecies. They concluded that further study is needed to determine if illinoensis warrants status as a distinct species. Molecular data were consistent with retention of regilla, cadaverina, ocularis, and crucifer in the genus Pseudacris.