CaliforniaHerps.com

A Guide to the Amphibians
and Reptiles of California

Southwestern Pond Turtle - Actinemys pallida

(Seeliger 1945)

= Southern Western Pond Turtle / Western Pond Turtle / Pacific Pond Turtle
= Emys marmorata pallida / Actinemys marmorata pallida / Clemmys marmorata pallida

Click on a picture for a larger view

Description • Taxonomy • Species Description • Scientific Name • Alt. Names • Similar Herps • References • Conservation Status 
Pacific Pond Turtle Range MapOrange: range of this species in California
Actinemys pallida - Southwestern Pond Turtle

Red: range of similar species
Actinemys marmorata - Northwestern Pond Turtle


Click on the map for a topographical view

Map with California County Names






observation link





Adults
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Adult male, Santa Barbara County
© Jason Butler		 Adult female, Santa Barbara County
© Brian Hubbs		 Adult male, Ventura County
© Patrick Briggs		 Adult male, San Luis Obispo Co.,
© Andrew Harmer
Pacific Pond Turtle Red-eared Slider Red-eared Slider Red-eared Slider
Adult, Los Angeles County
© Gregory Litiatco		 Adult, Santa Barbara County © Jeff Ahrens.
Animal capture and handling authorized under SCP or specific authorization from CDFW.
Pacific Pond Turtles Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Adult turtle eating a juvenile crayfish, San Luis Obispo County © Brian Hubbs Adult female, Los Angeles County
© Gregory Litiatco		 Adults and juveniles, Los Angeles County © Jeff Ahrens Adults and juveniles, Los Angeles County © Jeff Ahrens
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtles Pacific Pond Turtle
Adult, San Luis Obispo County
© Brian Hubbs		 Adult in habitat, Santa Barbara County
© Jason Butler		 Adults basking in February, Santa Barbara County. © Brian Hubbs Young male, Orange County
© Jason Jones
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Adult male, Los Angeles County © James R. Buskirk Adults, Monterey County
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Adult with damage to its carapace, Orange County © Jeff Ahrens.  Animal capture and handling authorized under SPC or specific authorization from CDFW.
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Adult, Monterey County
© Kinji Hayashi		 Adult female, Monterey County
© Kinji Hayashi		 Adult males, Riverside County
© Brian Hubbs		 Adult, San Luis Obispo County
© Joel A. Germond
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Young adult, San Luis Obispo County. Some adult females, like this one, show a pattern on the neck similar to that seen on juvenile turtles. © Joel A. Germond Adults basking at a creek in Ventura County © Brian Hubbs Adult, San Luis Obispo County
© Joel A. Germond
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Adult and juvenile, San Luis Obispo County © Joel A. Germond Adult and juvenile, San Luis Obispo County © Joel A. Germond Adult and juvenile, San Luis Obispo County © Joel A. Germond Adult, San Diego County
© Andrew Borcher
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
This San Luis Obispo County pond turtle was handled and released with permits by a licensed wildlife rehabilitation facility.
© Joel A. Germond 		Adult female basking on a plastic garbage can, L.A. County © Brian Hubbs
Pacific Pond Turtle Pacific Pond Turtle  
San Luis Obispo County © Ryan Sikola Adult and two juveniles, San Luis Obispo County © Joel Germond  
 
Southwestern Pond Turtles from east, and west of the San Francisco Bay, south to Monterey Bay

These turtles were previously identified as either unknown, Northwestern Pond Turtles, or intergrades with the Southwestern Pond Turtle which previously ranged south from the Monterey Bay area. The California Department Species of Special Concern Project range map labels them as Southwestern Pond Turtles, so I will do the same for now. You can see their map here. (See comment below.)

Pacific Pond Turtles Pacific Pond Turtles Pacific Pond Turtles Pacific Pond Turtle
Adults and juveniles, Alameda County
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Adult male, Contra Costa County, with pale throat characteristic of a male Adult, Alameda County Adult, Santa Clara County
© Neil Keung
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Adult female, Contra Costa County Adult, Alameda County Adult female, crossing a trail in late May, San Mateo County.
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Adults, Santa Clara County
© Neil Keung		 Immature adult, Alameda County. Some immature adult females show a pattern on the neck similar to that seen on juvenile turtles. © James R. Buskirk Adult male, San Mateo County Basking adult male (left) and female (right), San Mateo County.
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Four adult females basking, Alameda County Adults showing their climbing ability, Alameda County © Mark Gary Basking adult female, San Mateo County
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Two adult turtles from Santa Clara County with shells covered with algae.
© Cait Hutnik
(You can see lots more of Cait's pictures of pond turtles here.)		 Adult, Diablo Range, Alameda County
© Noah Morales		 Basking adult, San Mateo County
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle  
This adult pond turtle in Contra Costa County has large patches of algae growing on its shell. © Mark Gary Adult male (left) and adult female (right)
Alameda County, © Mark Gary
 These turtles from the Santa Monica Mountains in Los Angeles County all died during the 2015 drought.
© Huck Triggs		  
       
Differences Between Males and Females (genus Actinemys)
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Females usually have a pale throat mottled with dark markings.

 Adult female with mottled throat © Grayson Sandy
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtles
Males usually have a pale throat with no dark markings.
Males have raised areas towards the rear of the head, as you can see on this male from Santa Clara County. © Brian Hubbs Males have a slightly concave plastron
Left: Male
Right: Female
© Pierre Fidenci
       
Juveniles
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Hatchling, basking in situ, Los Angeles County © James R. Buskirk Hatchling, Monterey County
© Kinji Hayashi		 Hatchling, Orange County
© Jason Jones		 Hatchling next to U.S. 25 cent coin
(.955 inches [24.26 mm] in diameter)
Riverside County © Paul Maier
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Hatchling, Contra Costa County © Mark Gary Juvenile and hatchling pond turtles basking next to a Diablo Range Gartersnake
in a Contra Costa County pond. © Mark Gary
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle

These 2 turtles are neonate A. pallida. Both were found in early May, in different years in Alameda County.

These pictures show the presence of a residual yolk sac, or more commonly, of broadening at the abdomino-femoral junction on the plastron midline.
© James R. Buskirk

A "tiny juvenile" A. marmorata found in mid-June, San Mateo County.

Within days, growth begins, the first annulus is smooth in contrast to the granular character of the scutes of the noenate.  On the plastron this oval imprint from the yolk sac is lost.
© James R. Buskirk

 Hathling A. pallida, 7 May 2005, Alameda County.

The shell shows the granular character of the natal scutes, or areolae, typical among hard-shelled turtles of all families, but only present on tiny juvniles during the spring months.
© James R. Buskirk
Pacific Pond Turtle Pacific Pond Turtle    
Hatchling, Contra Costa County, with a flesh fly on its carapace. © Mark Gary This hatchling was found in early June in a Contra Costa County pond that was almost dried up. © Mark Gary    
       
       
Pond Turtle Tracking
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Santa Clara County turtles with transmitters attached to their shells. An antenna with a radio receiver that can find these transmitters is used to find the turtles and track their movement in order to study their behavior. Transmitters on females like the one on the far left are placed on the side of the shell to prevent obstacles to males during breeding. The transmitters are removed without damaging the shells when research is completed. © Neil Keung  
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle  
This Santa Clara County turtle travelled away from a dry creek in summer to bury itself in an upland location above the creek in oak woodland habitat where it will stay until the following Spring. The turtle was found by tracking the transmitter which you can see attached to its shell. © Neil Keung 
Find the turtles.

Both of these adult pond turtles were tracked with radio receivers to where they were hiding in shallow creeks in Santa Clara County. Both are very well camouflaged and could easily be overlooked. © Neil Keung		  
       
Western Pond Turetles Compared with Red-eared Sliders - Trachemys scripta elegans
Pacific Pond Turtle head and neck Pacific Pond Turtle head and neck Red-eared Slider Red-eared Slider
The head, neck, and throat of the female Western Pond Turtle is mottled, with no red stripe behind the eye. The head of the male Western Pond Turtle is dark with no red stripe behind the eye, and the throat is white.
© Grayson B. Sandy		 There is usually a prominent red stripe behind the eye of the Red-eared Slider. Some older or melanistic adult Red-eared Sliders do not have a red stripe behind the eye. © Will Kohn
Red-eared Slider Red-eared Slider Red-eared Slider
A useful way to differentiate Western Pond Turtles from Red-eared Sliders, according to wildlife biologist Brandon Stidum, "...is to look at the marginal scutes 8-12 (...the scutes above the tail, or back scutes). Sliders have bifid or slightly forked scutes, where Western Pond Turtles do not; theirs are all smooth and do not split (except for traumatic injuries, but it’s usually only one or a few, not all scutes). The forking in the tail gives red-eared sliders the appearance that the tail is serrated or split in appearance.  While looking for the presence and size of inguinal and axillary scutes is the best way to differentiate between the 2 once you have them in hand, a good way to do it from a distance is to look at the back scutes of the turtles."  Two adult Red-eared Sliders (left) compared with a much smaller adult Pacific Pond Turtle (right).
© Jeff Ahrens.
Animal capture and handling authorized under SCP or specific authorization from CDFW.

Ventral view of four adult Red-eared Sliders, with a much smaller adult Pacific Pond Turtle in the middle.
© Jeff Ahrens.
Animal capture and handling authorized under SCP or specific authorization from CDFW.
       
Identification Confusion with Melanistic Red-eared Sliders
red-eared slider red-eared slider Red-eared Slider Red-eared Slider
Melanistic adult Red-eared slider - Trachemys scripta elegans
Riverside County. © Bob Parkard		 Melanistic adult Red-eared slider, (without red on the head)
Riverside County © Bob Parkard		 Melanistic adult Red-eared with no red marks behind the eyes © Will Kohn
Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle Pacific Pond Turtle
Adult Pond Turtle, Mendocino county Adult female Pond Turtle
© Grayson Sandy		 Adult male Pond Turtle
red-eared slider
Click to enlarge 		Introduced melanistic sliders and old sliders whose red "ears" have faded, are often difficult to distinguish from the California native Western Pond Turtle, especially at a distance in the field, and even in hand. According to Bob Packard, with the Western Riverside County MSHCP Biological Monitoring Program, his organization confirms the identification of these turtles based on the presence of large inguinal and axillary scutes on the sliders, which are absent on the pond turtles (see illustration to the left) and by an interesting behavioral clue: the majority of sliders tend to be aggressive, biting readily, while pond turtles are far more reluctant to bite.

You can also use the information described above about differentiating the two species from a distance by observing the rear marginal scutes, or back scutes.

More pictures of melanistic sliders can be seen above.
   
Western Pond Turtle Eggs

These are pictures of the eggs of A. marmorata, which should be identical to those of this species, A. pallida.
  Pacific Pond Turtle eggs pond turtle life cycle  
  Western Pond Turtle Eggs,
© Patrick Briggs		 Western Pond Turtle Life Cycle:
Adult, Juvenile, and Egg, Butte County.
© The Chico Turtle Lab
  
       
Feeding Behavior
  Pacific Pond Turtle eggs Pacific Pond Turtle eggs  
  Adult feeding on the carcass of a Bullhead Catfish in Santa Clara County. Several turtles were observed circling the dead catfish, tearing off pieces to eat.
© Cait Hutnik
  
       
Western Pond Turtles and Drought
Pacific Pond Turtle
© Mark Gary

Western Pond Turtles have evolved to live with ponds that dry up. As the picture above shows, the small pond shown below in the hills of Alameda County supports an extraordinarily high number of Western Pond Turtles - as many as 175 have been counted here. But in the fall of 2021 the pond dried up almost completely during a period of severe drought. Most of the turtles were gone in mid October when more than 20 of them were rescued and taken to the San Francisco Zoo. After winter rains re-filled the pond in the middle of March 2022 at least 87 live but emaciated turtles were counted at the pond. The rescued turtles had not been reintroduced yet which indicates that at least 87 turtles returned to the pond on their own. They most likely walked away from the pond and spent the winter buried in soil or leaf litter and then returned before mid March. It's possible even more will return. It's also possible that the pond will dry up again this year if drought conditions continue.
Pacific Pond Turtle Habitat Pacific Pond Turtle Habitat Pacific Pond Turtle Habitat Pacific Pond Turtle Habitat
The pond completely full in March 2010, a year with plenty of rain. The full pond from a distance in March, 2011, another non-drought year. © Mark Gary
The pond level has declined considerably in early September 2021, a severe drought year. 151 turtle noses and carapaces were counted in the water that remained.
© Mark Gary
One month later in early October 2021, the water level of the pond is still declining. Only 46 turtles were counted.
Pacific Pond Turtle Habitat Pacific Pond Turtle Habitat Pacific Pond Turtle Habitat Pacific Pond Turtle Habitat
© Mark Gary
In mid October 2021 the pond is almost completely dry with only a few turtles remaining. More than 20 turtles were rescued from the mud at this time and transferred to the San Francisco Zoo.
 © Mark Gary
Heavy rain filled the pond to this level in late October 2021, but most of the turtles were already gone. The water level continued to increase during the winter rainy season.
 © Mark Gary
This is the pond in early May, 2022. It's covered with algae, which makes counting turtles difficult, but about 60 turtles were seen.		 © Mark Gary
The pond in early November, 2022 has dried up again with water only a couple of inches deep in most parts. No turtles were observed.
       
Habitat
Pacific Pond Turtle Habitat Pacific Pond Turtle Habitat california toad habitat Pacific Pond Turtle Habitat
Habitat, San Luis Obispo County Habitat, Afton Canyon, San Bernardino County. According to Stebbins (2003) the turtles in this desert population may be a distinct taxon. Habitat with turtle, Los Angeles County
© James R. Buskirk
Pacific Pond Turtle Habitat Pacific Pond Turtle Habitat Pacific Pond Turtle Habitat Pacific Pond Turtle Habitat
Habitat, Orange County © Jason Jones Habitat, Panoche Valley, Fresno County
© James R. Buskirk 		Habitat, San Luis Obispo County
© Joel A. Germond
Pacific Pond Turtle Habitat Pacific Pond Turtle Habitat Pacific Pond Turtle Habitat Pacific Pond Turtle Habitat
Habitat, San Luis Obispo County
© Joel A. Germond		 Habitat, small creek, Santa Clara County Habitat, Contra Costa County Adult basking on branches in pond, Contra Costa County.
Where no objects are available in the water for basking, pond turtles will use branches overhanging the water, or they will bask on the shore.
Pacific Pond Turtle Habitat Pacific Pond Turtle Habitat Red-eared Slider Habitat Pacific Pond Turtle Habitat
Habitat, San Mateo County Habitat, Alameda County Habitat, small lake, Santa Clara County
© Cait Hutnik		 Habitat, Alameda County
© Mark Gary
Pacific Pond Turtle Habitat California Red-legged Frog Habitat Pacific Pond Turtle Habitat x
Habitat, San Mateo County Habitat, Contra Costa County Habitat, 2,300 ft., Monterey County San Mateo County Park Sign
       
Short Videos of Southwestern Pond Turtles
Pacific Pond Turtles Pacific Pond Turtle Pacific Pond Turtles  
Southwestern Pond Turtles compete for limited basking space on a small pond. Southwestern Pond Turtles
basking in the sun.		 Southwestern Pond Turtles
in an Alameda County pond.		  
     
Description
 
Size
3.5 - 8.5 inches in shell length (8.9 - 21.6 cm). (Stebbins 2003)
Hatchlings are aproximately 1 inch (2.5 cm) in shell length.
The tail of a young turtle is almost as long as its shell.
Appearance
A small to medium-sized drab dark brown, olive brown, or blackish turtle with a low unkeeled carapace.
Color and Pattern
Usually with a pattern of lines or spots radiating from the centers of the scutes.
The plastron lacks hinges, and has 6 pairs of shelds which can be cream or yellowish in color with large dark brown markings, or unmarked.
The legs have black speckling and may show cream to yellowish coloring.
The head usually has a black network or spots may show cream to yellowish coloring.
Western Pond Turtles south of the Transverse Ranges tend to be lighter, from yellowish brown to light brown.
Differences Between Males and Females

Males

Size: males are smaller than females
Throat: light in color with no markings
Chin: more pointed than on females
Head: larger than females
Carapace: a lower dome (flatter shell) than females
Plastron: concave
Tail: wider and thicker at the base than females

Females

Size: females are larger than males
Throat: dark speckled markings
Chin: more rounded than on males
Head: smaller than males
Carapace: a higher dome (taller shell) than males
Plastron: flat or convex
Tail: thinner at the base than males

Life History and Behavior

Activity
Diurnal and aquatic.

Typically active from February through November, with the length of the active season depending on the temperature of the habitat.
May be active during warm periods in winter in warmer climates.

Pond turtles are often seen on a log or rock basking above the water, but they will quickly slide into the water when they feel threatened.
Pond turtles seldom bask by floating at the surface of the water.


Hibernation and Estivation

Some Western Pond Turtles slow down their metabolic processes and hibernate underwater during several months in the Winter. They often cluster in the shallow end of the pond. They survive so much time underwater by using cloacal respiration - pumping water through the cloaca through pouches that function similar to gills - extracting oxygen from the water and releasing carbon monoxide.

Other pond turtles pass the Winter by moving to woodlands above the creek or pond they inhabit and burying themselves in loose soil or entering California ground squirrel burrows, where they down their metabolic processes. They remain underground through the Winter until temperatures warm up enough for them to become active. If they leave a creek due to heavy winter flows, they will return to the creek in Spring when the flow of the water subsides.

During hot dry Summer droughts, some pond turtles will estivate by burying themselves in the soft bottom mud of a pond or creek, again relying on cloacal respiration.
When creeks and ponds dry up in Summer, some pond turtles that inhabit creeks will travel along the creek until they find an isolated deep pool, others stay within moist mats of algae in shallow pools.
Turtles Walking on Land Do Not Always Need to be Picked Up and Rescued
Turtles sometimes leave the water to search for food, a better place to live, a mate, or to lay their eggs in the spring - typically from March to June. If you see a turtle walking on the land, it is probably not sick or lost, so the best thing you can do for the turtle is to leave it alone. Some people want to help a turtle they think is in danger by picking it up and bringing it home or to a wildlife rehabilitation center, but most of the time this harms the turtle by removing it from the wild without reason. Sometimes turtles do get lost or stranded in yards or on busy roads or somewhere where they may be in danger. If you find one in such a situation, it's ok to move it out of danger, but it's best to leave it in a safe place as close to where you found it as possible.
Territoriality
When seeking or protecting a basking spot, Western Pond Turtles may show aggressive behavior by opening the mouth and exposing the yellow and pinkish mouth lining to scare off another turtle. Occasionally they will also bite or ram.
Diet and Feeding
Eats aquatic plants, invertebrates, worms, frog and salamander eggs and larvae, crayfish, carrion, and occasionally frogs and fish.
Reproduction
Adults do not mate until they are aproximately eight to ten years old.
Mating occurs in April and May.

Sometime between late April and August, females climb onto land to dig a nest, usually along stream or pond margins in areas with full sunlight, where they lay a clutch of 2 - 11 eggs. Some females lay two clutches in a year while others lay eggs every other year.
Females in the Bay Area were found to prefer to lay their eggs in sunny areas with grass about a foot and a half high covering about 85 percent of the ground. (Carolyn Jones, SFGate.com, 7/31/13)

The length of incubation is not known. It may vary with altitude and latitude. Eggs incubated in a laboratory hatched in 73-81 days.
Hatchlings may emerge in late summer or fall, but some turtles may overwinter in the nest and emerge the following spring.
(Ernst, Barbour, & Lovich, 2009)
Habitat
Found in ponds, lakes, rivers, streams, creeks, marshes, and irrigation ditches, with abundant vegetation, and either rocky or muddy bottoms, in woodland, forest, and grassland. In streams, prefers pools to shallower areas. Logs, rocks, cattail mats, and exposed banks are required for basking. May enter brackish water and even seawater.
Geographical Range
According to the paper that split the former species into two species ** the [Southwestern] Pond Turtle "... is restricted to those populations inhabiting the central coast range south of the San Francisco Bay area to the species’ southern range boundary, including the Mojave River ... Although we tentatively include populations from Baja California in E. pallida, we also recognize that these animals may represent a distinct species pending results from additional analyses.") (Pond turtles in northern Baja California have disappeared throughout most of their former range.)  All populations of pond turtles in California  "... north of the San Francisco Bay area plus populations from the Great Central Valley north including the apparently introduced Nevada population..." are the [Northwestern] Pond Turtle.

** Phillip Q. Spinks, Robert C. Thomson, and H. Bradley Shaffer.
The advantages of going large: genome wide SNPs clarify the complex population history and systematics of the threatened western pond turtle.
Molecular Ecology. 23(9): 2228-2241. June, 2014.

It is not clear from the Spinks, Thomson, and Shaffer paper referenced above what species of Western Pond turtle occurs immediately south, east, and west of the San Francisco Bay, since no specimens from that area were used in the study which described the two species. Nor is there any mention of hybrids occurring in this area, only this: "Emys marmorata and E. pallida show very limited intergradation in a few populations in the northern central coast range and adjacent Sierra Nevada foothills, although at all intergrade sites we also found pure individuals of the locally prevalent species.")

On my range maps I previously showed the area south, east, and west of the San Francisco Bay as an "area of uncertainty." In 2017 I changed my range maps to follow the only source I can find that shows the two species range in that part of the bay area: Robert C. Thomson, Amber N. Wright, and H. Bradley Shaffer. California Amphibian and Reptile Species of Special Concern. University of California Press, 2016. Their range map (which is now online at the CDFW website) shows A. pallida ranging throughout area south, east, and west of the San Francisco Bay. I do the same now, to be consistent with the state Species of Special Concern information. The eastern boundary and contact area between the two species is apparently the edge of the South Coast Ranges where they meet the floor of the great valley.


An isoloated population of A. pallida occurs along the Mojave River at Camp Cody and at Afton Canyon where water is still present in the mostly-dry river. These turtles in the middle of the Mojave Desert are a relict population from a time many thousands of years ago when the region received more rainfall and streams that drained the mountains and flowed into the Pacific were ony a few miles from streams that fed the Mojave river, which flowed year-round. Apparently some turtles were able to cross the distance to the Mojave River drainage. (Read more about these desert turtles here - James Cornett, The Desert Sun, 6/30/12.)
Full Species Range Map
Elevational Range
Stebbins (2003) describes the elevation range of the Western Pond Turtle - Clemmys marmorata, which has now been split into two species, as "Sea level to around 6,696 ft. (2,041 m) but mostly below 4,980 ft. (1,371 m)."
Notes on Taxonomy
Previously, the Western Pond Turtle, Actinemys marmorata, was split into two subspecies: A. m. marmorata and A. m. pallida.

The single species has been split into two full species, corresponding to the previous two subspecies - Actinemys marmorata, and Actinemys pallida.

The authors "...propose using the name Emys marmorata for all populations north of the San Francisco Bay area plus populations from the Great Central Valley north.... Emys pallida is restricted to those populations inhabiting the central coast range south of the San Francisco Bay area to the species’ southern range boundary, including the Mojave River." **

** Phillip Q. Spinks, Robert C. Thomson, and H. Bradley Shaffer.
The advantages of going large: genome wide SNPs clarify the complex population history and systematics of the threatened western pond turtle.
Molecular Ecology. 23(9): 2228-2241. June, 2014.

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Janzen, Hoover, and Shaffer (1997 Chelonian Conservation Biology 2(4): 623-626) concluded that southern populations of A. marmorata, found in Baja California and adjacent southern California, are a different species from those to the north.

Spinks and Shaffer argued that subspecies should be abandoned because they are not supported on molecular grounds. (Spinks and Shaffer - 2005 Mol. Ecol. 14:2047-2064)

In 2010 Spinks (Spinks et al., 2010, Mol. Ecol. 19: 542-556) demonstrated deep phylogeographic divergence within the species, potentially warranting species recognition.

The Afton Canyon population may be a distinct taxon. (Stebbins 2003)


Alternate and Previous Names (Synonyms)

Actinemys marmorata pallida - Southwestern Pond Turtle (Stebbins & McGinnis 2012)
Clemmys marmorata pallida - Southwestern Pond Turtle (Stebbins 1966, 1985, 2003)
Clemmys marmorata - Pacific Pond Turtle (Stebbins 1954)
Clemmys marmorata - Pacific Mud Turtle (Emys marmorata; Emys nigra; Atinemys marmorata; Clemmys Wosnessenskyi; Chelopus marmoratus. Western Pond Turtle; Pacific Terrapin; California Terrapin; California Mud Turtle; Western Terrapin; Water Turtle) (Grinnell and Camp 1917)

Conservation Issues  (Conservation Status)

"Pond turtles from southern California are in precipitous decline, with few stable, reproducing populations known between Los Angeles and the US/Mexico border. The recognition of E. pallida as a distinct species, and the possibility that stable populations in Baja California represent a unique evolutionary lineage emphasize the critical need for immediate conservation in southern California and Baja California, Mexico." (Phillip Q. Spinks, Robert C. Thomson, and H. Bradley Shaffer.**)


The Western Pond Turtle is in decline throughout 75 - 80% of its range. (Stebbins, 2003.) There a number of reasons for this decline.

Beginning in the 19th century, the commercial harvesting of Western Pond Turtles for food was a major threat to the species. That trade continued at least into the 1930s: Nussbaum, Brodie & Storm, 1983, remark that in the 1930s, Western Pond Turtles were trapped for food in California and sold to markets in San Francisco.

Another cause for the decline of the species was the massive wetland drainage projects in the Great Valley of the early 20th century which destroyed numerous wetlands and lakes and altered rivers, all of which destroyed or reduced suitable habitat for the Western Pond Turtle. Tulare lake, now gone, was once the home to an estimated 3.5 million pond turtles, almost all of which are now extinct in the area. (Stebbins & McGinnis, 2012.) The destruction or degredation of other wetlands throughout the state has certainly also added to the decline.

The introduction of non-native turtles into Western Pond Turtle habitat, especially the two most successful invasive turtle species, the Red-eared Slider and the Painted Turtle, has been another cause of the decline of the Western Pond Turtle. Both species are common in the pet trade and feral turtles now found in California were most likely released by their owners. Since the Western Pond Turtle is the only native freshwater turtle in its historic range, it did not develop the ability to successfully compete for resources with other species of turtles, and both the Red-eared Slider and the Painted Turtle produce nearly twice as many offspring as the pond turtle which allows them to overwhelm and out-compete the pond turtle population.

Another threat to the Western Pond Turtle has been the American Bullfrog, an invasive species that has spread throughout the state. In 1994 report, Dan C. Holland writes that the invasive bullfrog (Rana catesbeiana) is a known predator of Western Pond Turtles, and the report includes a picture of a bullfrog preying on a juvenile pond turtle in San Diego County. Bullfrogs breed in such large numbers that adults can eventually eat so many hatchling turtles that fewturtles can survive to adulthood and after the existing adults die off there will be no more turtles at that location.  (Holland, Dan C. The Western Pond Turtle: Habitat and History. Final Report. Prepared for: U. S. Department of Engergy Bonneville Power Administration Environment, Fish and Wildlife... Portland OR.1994)

Photographic evidence also exists that shows that bullfrogs eat hatchling painted turtles.

Taxonomy
Family Emydidae Box and Basking Turtles Gray, 1825
Genus Actinemys Western Pond Turtles Agassiz, 1857
Species

 pallida Southwestern Pond Turtle (Seeliger 1945)
Original Description
Clemmys marmorata - (Baird and Girard, 1852) - Proc. Acad. Nat. Sci. Philadelphia, Vol. 6, p. 177

from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz

Meaning of the Scientific Name
Actinemys - actin - ray or beam, and -emys - turtle
pallida - pale  - refers to the light background color of the sides and ventral surface of the neck

from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
Related or Similar California Herps
Actinemys marmorata - Northwestern Pond Turtle

C. p. bellii - Western Painted Turtle

T. s. elegans - Red-eared Slider
More Information and References (Referring to A. marmorata and A. pallida)
California Department of Fish and Wildlife

SDNHM

James R. Buskirk has generously provided age and gender identification for many of the turtles shown here.

Stebbins, Robert C., and McGinnis, Samuel M.  Field Guide to Amphibians and Reptiles of California: Revised Edition (California Natural History Guides) University of California Press, 2012.

Stebbins, Robert C. California Amphibians and Reptiles. The University of California Press, 1972.

Flaxington, William C. Amphibians and Reptiles of California: Field Observations, Distribution, and Natural History. Fieldnotes Press, Anaheim, California, 2021.

*Samuel M. McGinnis and Robert C. Stebbins. Peterson Field Guide to Western Reptiles & Amphibians. 4th Edition. Houghton Mifflin Harcourt Publishing Company, 2018.

Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003.

Behler, John L., and F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992.

Powell, Robert., Joseph T. Collins, and Errol D. Hooper Jr. A Key to Amphibians and Reptiles of the Continental United States and Canada. The University Press of Kansas, 1998.

Bartlett, R. D. & Patricia P. Bartlett. Guide and Reference to the Turtles and Lizards of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2009.

Carr, Archie. Handbook of Turtles: The Turtles of the United States, Canada, and Baja California. Cornell University Press, 1969.

Ernst, Carl H., Roger W. Barbour, & Jeffrey E. Lovich. Turtles of the United States and Canada. Smithsonian Institution 1994. (2nd Edition published 2009)

St. John, Alan D. Reptiles of the Northwest: Alaska to California; Rockies to the Coast. Lone Pine Publishing, 2002.

Nussbaum, R. A., E. D. Brodie Jr., and R. M. Storm. Amphibians and Reptiles of the Pacific Northwest. Moscow, Idaho: University Press of Idaho, 1983.

Lemm, Jeffrey. Field Guide to Amphibians and Reptiles of the San Diego Region (California Natural History Guides). University of California Press, 2006.

Watch more short movies of this turtle at Endangered Species International (www.endangeredspeciesinternational.org)

Phillip Q. Spinks, Robert C. Thomson, and H. Bradley Shaffer.
The advantages of going large: genome wide SNPs clarify the complex population history and systematics of the threatened western pond turtle.
Molecular Ecology. 23(9): 2228-2241. June, 2014.

Robert C. Thomson, Amber N. Wright, and H. Bradley Shaffer. California Amphibian and Reptile Species of Special Concern. University of California Press, 2016.

Conservation Status

The following conservation status listings for this animal are taken from the April 2024 State of California Special Animals List and the April 2024 Federally Listed Endangered and Threatened Animals of California list (unless indicated otherwise below.) Both lists are produced by multiple agencies every year, and sometimes more than once per year, so the conservation status listing information found below might not be from the most recent lists. To make sure you are seeing the most recent listings, go to this California Department of Fish and Wildlife web page where you can search for and download both lists:
https://www.wildlife.ca.gov/Data/CNDDB/Plants-and-Animals.

A detailed explanation of the meaning of the status listing symbols can be found at the beginning of the two lists. For quick reference, I have included them on my Special Status Information page.

If no status is listed here, the animal is not included on either list. This most likely indicates that there are no serious conservation concerns for the animal. To find out more about an animal's status you can also go to the NatureServe and IUCN websites to check their rankings.

Check the current California Department of Fish and Wildlife sport fishing regulations to find out if this animal can be legally pursued and handled or collected with possession of a current fishing license. You can also look at the summary of the sport fishing regulations as they apply only to reptiles and amphibians that has been made for this website.

The Special Animals List recognizes western pond turtles as one full species - Emys marmorata - Western Pond Turtle.
It does not track the species by the two formerly recognized subspecies nor does it recognize the 2014 two species of pond turtles theory (as this site does.)


Special Animals List Notes 7/23:

western pond turtle

1) CNDDB tracks western pond turtle at the full species level, based on the determination that the previous subspecies split was not warranted (Spinks, P.Q. and Shaffer, H.B. 2005. Range-wide molecular analysis of the western pond turtle (Emys marmorata): cryptic variation, isolation by distance, and their conservation implications. Molecular Ecology 14(7):2047- 2064).

2) Genus was updated to Emys based on findings in: Spinks, P.Q. and Shaffer, H.B. 2009. Conflicting mitochondrial and nuclear phylogenies for the widely disjunct Emys (Testudines: Emydidae) species complex, and what they tell us about biogeography and hybridization. Systematic Biology. 58(1):1-20.

Organization Status Listing  Notes
NatureServe Global Ranking G3G4 Vulnerable - Apparently Secure
NatureServe State Ranking S3 Vulnerable
U.S. Endangered Species Act (ESA) PT Proposed Threatened
California Endangered Species Act (CESA) None
California Department of Fish and Wildlife SSC Species of Special Concern
Bureau of Land Management S Sensitive
USDA Forest Service S Sensitive
IUCN VU Vulnerable


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