Sierran Treefrog
Pseudacris sierra
Description
Physical
Our smallest frog, adults are typically smaller than 5cm (2in)B1 in length. Toe pads are present at end of toes. Toe pads allow the species to readily climb most surfaces, including glass. Lacks dorsolateral fold. Eardrum not prominent.
Color and Pattern
Highly variable in color. Yellow, green, tan, brown and red variations exist in various degrees. Some specimens exhibit one color phase on their back and a different color phase along their sides. Contrary to popular belief, this species can not change color between the different color phases. They do however change how light or dark the color appears and can do so quite rapidly.
All specimens have a thick dark stripe on each side of the face that extend from the nose through the eye generally to the top of the front limb. The eye stripe may be difficult to see in dark individuals. Dark banding is often but not always present on the limbs, especially the hind limbs. Irregular spotting is often but not always present on the back.
Sexual Dimorphism
During the breeding season, sexually mature males have a very wrinkly brownish underside to their throat. Females that have not yet laid their eggs often appear bloated at the sides.
Diet
Feeds primarily on invertebrates. If you leave your porch light on during the summer, you can sometimes find this frog on your wall near the porch light feeding on the insects the porch light attracts.
Distribution Range
Detailed Map
Museum records taken from following institutions: CAS Herps, MVZ Herps.
Museum record sets fetched .
Probably found throughout Shasta County.
Typical Elevation
Based on records in our database, in Shasta County the Sierran Treefrog is typically found at elevations from 172m to 2268m (564ft to 7439ft).
Voice
Despite being our smallest frog, this is our loudest frog and most frequently heard. The call of this frog is also commonly used by Hollywood when a film or television show requires audio of a frog croaking.
Lone individuals often call with a slow lower pitched raspy Kr-e-e-e-e-e-ck while away from breeding sites, even from inside holes where they are hiding. Multiple males will often call in chorus in response to each other with a faster higher pitched one or two syllable Krik-krik.
Reproduction and Young
Most reproduction in our area occurs between January and early Summer, but they also are known to breed in the fall.
Eggs are laid in small clusters usually attached to aquatic vegetation in temporary or permanent pools or in slow moving streams, the egg clusters typically have 25 to 75 eggs per cluster (reference needed). Egg sacs are a clear gelatin ball around a stick or plant branch with dark centers at the center of individual eggs that make up the ball.
Tadpoles are a mottled olive green and can be distinguished from other tadpoles by the position of their eyes and the shape of their tail. When looking straight down at a Sierran Treefrog tadpole, the eyes will appear at the very edge of the outline. The tail fin starts at the top their head.
Recently transformed frogs usually start appearing in Late April to May at lower elevations (IE Redding), may appear later at higher elevations. Recently transformed frogs are about the size of a watch battery.
Additional Information
CaliforniaHerps.com
Additional information on this species in general can be found at http://www.californiaherps.com/frogs/pages/p.sierra.html.
Stebbins 2003 Field Guide
The Stebbins 2003 account for this species may be found on pg 222.
Nature Serve
NatureServe Report: Pseudacris regilla
Notes
Until recently, the Sierran Treefrog was known as the Pacific Treefrog (Pseudacris regilla).
While there is still some controversy, that species has recently been split up into 3 distinct speciesA1, including our Sierran Treefrog.
An older look at the taxonomy wants to keep them as one species but split them into multiple subspeciesA2. By that groups taxonomy, our frogs would be the Cascade Mountain Treefrog (Pseudacris regilla cascadae). That taxonomy, however, does not currently have much support.
Images
Unless otherwise noted, all images are of wild specimens in Shasta County.
Please be kind, do not hotlink images and do not use images without permission of the copyright owner.
©Michael A. Peters
Example of specimen expressing two different color phases. In situ under water on creek bottom. Sulfur Creek. Redding, CA
©Michael A. Peters
Recently transformed brown phase. Hornbeck Trail, Keswwick recreation area. Shasta County, CA
©Michael A. Peters
Adult male. Notice the dark underside of throat indicating specimen is a male. Shasta Lake City, CA
©Michael A. Peters
Adult male. Notice the prominent toepads that distinguish this species from all our other frogs. Shasta Lake City, CA
Habitat Shots
Unless otherwise noted, these habitat shots are from within Shasta County where this species is known to occur.
©Michael A. Peters
Breeding Pool. This pool also serves as a nursery to trout fingerlings, which prey upon tadpoles. As a result, the tadpoles are not often seen. However, as you move rocks on the bottom of the pool, you often find tadpoles hiding under them. Sulfur Creek. Redding, CA
©Michael A. Peters
Breeding Pool. No trout fingerlings were present in this pool. As a result, the tadpoles were seen freely swimming at all depths of the pool. Sulfur Creek. Redding, CA.
©Michael A. Peters
Breeding Ditch. This is a small temporary pool that will probably be completely dry by mid summer. Treefrogs frequently use such pools for breeding. Whether the tadpoles mature or not then becomes a race against time. Sulfur Creek Drainage. Redding, CA.
Multimedia
Fall Chorus. A few egg sacs were found, they hatched into tadpoles, but it appears that the tadpoles perished in the followimng cold weather. Redding, CA