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Western pond turtle

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Species of turtle

Western pond turtle

Conservation status
Vulnerable (IUCN 2.3)^[2]
Vulnerable (NatureServe)^[3]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Testudines
Suborder:	Cryptodira
Family:	Emydidae
Genus:	Actinemys
Species:	A. marmorata^[1]
Binomial name
*Actinemys marmorata^[1]* (Baird andGirard, 1852)

The range of the western pond turtle.
Synonyms^[4]
Emys marmorataBaird & Girard, 1852 Emys nigraHallowell, 1854 Clemmys wosnessenskyiStrauch, 1862 Clemmys marmorataStrauch, 1862 Actinemys nigraAgassiz, 1857 Geoclemmys nigraGray, 1870 Clemmys hesperiaO.P. Hay, 1903 Actinemys marmorataHolman &Fritz, 2001

Thewestern pond turtle (Actinemys marmorata), also knowncommonly as thePacific pond turtle is aspecies of small to medium-sizedturtle in thefamily Emydidae. The species isendemic to the western coast of the United States and Mexico, ranging from western Washington state to northernBaja California. It was formerly found inCanada (inBritish Columbia), but in May 2002, the CanadianSpecies at Risk Act listed the Pacific pond turtle as beingextirpated.

Taxonomy and systematics

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Its genus classification is mixed.Emys andActinemys were used among published sources in 2010.^[5] It was known by several names in the Indigenous languages of its range, including kʰá:wanaka: (Northeastern Pomo), kʰa:wana (Southern Pomo), and ʔaləšək (Lushootseed).

Description

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Thedorsal color ofA. marmorata is usually dark brown or dull olive, with or without darker reticulations or streaking. Theplastron is yellowish, sometimes with dark blotches in the centers of the scutes. The straightcarapace length is 11–21 cm (4.5–8.5 in). The carapace is low and broad, usually widest behind the middle, and in adults is smooth, lacking a keel or serrations. Adult western pond turtles are sexuallydimorphic, with males having a light or pale yellow throat.

Distribution

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The western pond turtle originally ranged from northernBaja California, Mexico, north to the southern regions ofBritish Columbia, Canada. It was once a large part of a major fishery onTulare Lake, California, supplying San Francisco with a local favorite, turtle soup, as well as feed for hogs that learned to dive for it in the shallows ofHog Island, also on Tulare Lake.^{[citation needed]} As of 2007, it has become rare or absent in thePuget Sound region ofWashington. It has a disjunct distribution in most of the Northwest, and some isolated populations exist in southern Washington. The western pond turtle is now rare in theWillamette Valley north ofEugene, Oregon, but abundance increases south of that city where temperatures are higher. It may be locally common in some streams, rivers and ponds in southern Oregon. A few records are reported east of theCascade Mountains, but these may have been based on introduced individuals. It ranges up to 305 m (1,001 ft) in Washington, and to about 915 m (3,002 ft) in Oregon. It also occurs in Uvas Canyon area, Santa Cruz Mountains, California, and in theNorth Bay, and lakes such asFountaingrove Lake. Many taxonomic authorities now split what had been considered one species of turtle into two species. The southern species is namedActinemys pallida, or the southwestern pond turtle. Its range is southern California and Mexico. The northern species remainsActinemys marmorata, with a range of northern California northward. It is then usually referred to as the northwestern pond turtle.

Ecology and behavior

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The western pond turtle occurs in both permanent and intermittent waters, including marshes, streams, rivers, ponds, and lakes. It favors habitats with large numbers of emergent logs or boulders, where individuals aggregate to bask. They also bask on top of aquatic vegetation. Consequently, this species is often overlooked in the wild. However, it is possible to observe resident turtles by moving slowly and hiding behind shrubs and trees.

A. marmorata can be encouraged to use artificial basking substrate, or rafts, which allows for easy detection of the species in complex habitats.

In addition to its aquatic habitat, terrestrial habitat is also extremely important for the western pond turtle. Since many intermittent ponds can dry up during summer and fall months along the west coast, especially during times of drought, the western pond turtle can spend upwards of 200 days out of water. Many turtles overwinter outside of the water, during which time they often create their nests for the year. Overwintering sites can sometimes be 500 meters from a main body of water^[6]

Diet

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The western pond turtle isomnivorous and most of its animal diet includes insects, crayfish, and other aquatic invertebrates. Fish, tadpoles, and frogs are eaten occasionally, and carrion is eaten when available. Plant foods include filamentous algae, lily pads, tule and cattail roots. Juveniles are primarily carnivorous, and eat insects and carrion. At about age three they begin to eat plant matter.

δ¹³C,δ¹⁵N, andδ³⁴S analysis of western pond turtle fossils from theLate Pleistocene ofRancho La Brea has found that their diets during the Late Pleistocene were overall broadly similar to their present-day dietary habits.^[7]

Predation and threat

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Raccoons, otters, ospreys, and coyotes are the biggest natural threats to this turtle, its eggs, and hatchlings. Weasels and large fish are also known predators.^[8] Non-native predators include bullfrogs, crayfish, and opossums.

Young turtles are also eaten bydomestic dogs,American black bears,California mountain kingsnakes,common kingsnakes, gopher snakes (Pituophis melanoleucus),yellow-bellied racers,largemouth bass,eastern spotted skunks,gray foxes,red foxes,common ravens andAmerican crows.^[9]

In the past the turtle was exploited as food by both indigenous peoples and American settlers. After the goldrush in California a large "fishery" emerged processing turtles from the San Francisco Bay Estuary into canned soup for markets East.

Finally, this species is still threatened by humankind. Due tohabitat destruction and modification, this species is currently listed as vulnerable on theIUCN Red List and byNatureServe. It also faces significant competition from introduced invasive species, especially the red-eared slider. With the removal of ponds, modification of sandy banks needed for egg laying, draining of wetlands, this species is now vulnerable. Efforts at reintroducing this turtle to its native range have met with limited success.

Reproduction

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Sexually mature females of the western pond turtle produce 5–13 eggs perclutch. They deposit eggs either once or twice a year. They may travel some distance from water for egg-laying, moving as much as 0.8 km (1/2 mile) away from and up to 90 m (300 ft) above the nearest source of water, but most nests are within 90 m (300 ft) of water. The female usually leaves the water in the evening and may wander far before selecting a nest site, often in an open area of sand or hardpan that is facing southwards. The nest is flask-shaped with an opening of about 5 cm (2 in). Females spend considerable time covering up the nest with soil and adjacent low vegetation, making it difficult for a person to find unless it has been disturbed by a predator.

Hatchlings

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The vast majority of western pond turtle hatchlings overwinter in the nest, and this phenomenon seems prevalent in most parts of the range, especially northern areas. This might explain the difficulty researchers have had in trying to locate hatchlings in the fall months. Winter rains may be necessary to loosen the hardpan soil where some nests are deposited. It may be that the nest is the safest place for hatchlings to shelter while they await the return of warm weather. Whether it is hatchlings or eggs that overwinter, young first appear in the spring following the year of egg deposition. Individuals grow slowly in the wild, and their age at their first reproduction may be 10 to 12 years in the northern part of the range. The western pond turtle may survive more than 50 years in the wild.

References

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^Rhodin 2010, p. 000.105
^Tortoise & Freshwater Turtle Specialist Group (2016) [errata version of 1996 assessment]."Actinemys marmorata".IUCN Red List of Threatened Species.1996 e.T4969A97292542.doi:10.2305/IUCN.UK.1996.RLTS.T4969A11104202.en. Retrieved29 December 2023.
^"Actinemys marmorata. NatureServe Explorer 2.0".explorer.natureserve.org. Retrieved9 December 2022.
^SpeciesActinemys marmorata atThe Reptile Database. www.reptile-database.org.
^Rhodin 2010, p. 000.139
^Reese, D. A.; Jr..Welsh, Hartwell H. (1997)."Use of terrestrial habitat by western pond turtles (Clemmys marmorata): implications for management".Pages 352-357 in Proceedings: Conservation, Restoration, and Management of Turtles and Tortoises. An International Conference. New York Turtle and Tortoise Society.
^Fuller, Benjamin T.; Southon, John R.; Fahrni, Simon M.; Farrell, Aisling B.; Takeuchi, Gary T.; Nehlich, Olaf; Guiry, Eric J.; Richards, Michael P.; Lindsey, Emily L.; Harris, John M. (1 January 2020)."Pleistocene paleoecology and feeding behavior of terrestrial vertebrates recorded in a pre-LGM asphaltic deposit at Rancho La Brea, California".Palaeogeography, Palaeoclimatology, Palaeoecology.537: 109383.doi:10.1016/j.palaeo.2019.109383. Retrieved24 November 2025 – via Elsevier Science Direct.{{cite journal}}: CS1 maint: article number as page number (link)
^"Wildscreen Arkive".arkive.org. Archived fromthe original on 23 January 2009. Retrieved26 April 2016.
^Emys marmorata (Western pond turtle, Pacific pond turtle). Animal Diversity Web.https://animaldiversity.org/accounts/Emys_marmorata/

Bibliography

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Holland, Dan C., PhD. The Western Pond Turtle: Habitat and History, Final Report. U.S. Department of Energy, Bonneville Power Administration, Division of Fish and Wildlife; Wildlife Diversity Program, Oregon Department of Fish and Wildlife, August 1994.
Rhodin, Anders G.J.; van Dijk, Peter Paul; Iverson, John B.; Shaffer, H. Bradley (2010-12-14)."Turtles of the World 2010 Update: Annotated Checklist of Taxonomy, Synonymy, Distribution and Conservation Status"(PDF).Archived(PDF) from the original on 2011-07-17. Retrieved2010-12-15.
"Western pond turtle (Actinemys marmorata)".Wildscreen ARKive. Archived fromthe original on 1 February 2019. RetrievedApril 25, 2016.

External links

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Field Identification: Guide to Distinguishing Western Pond Turtles (Actinemys spp.) from Common Pond Sliders (Trachemys spp.)

Emydidae family

Kingdom:Animalia
Phylum:Chordata
Class:Reptilia
Order:Testudines
Suborder:Cryptodira
Superfamily:Testudinoidea
Family:Emydidae

Genera

Species of theEmydidae family

Northern red-bellied cooter(Pseudemys rubriventris)

Chrysemys

Painted turtle

Clemmys

Spotted turtle

Deirochelys

Chicken turtle

Actinemys

Emys

Emydoidea

Blanding's turtle

Glyptemys

Graptemys

Malaclemys

Diamondback terrapin

Pseudemys

Terrapene

Trachemys

†Wilburemys

†Wilburemys yakimensis

Phylogenetic arrangement of turtles based onturtles of the world 2017 update: Annotated checklist and atlas of taxonomy, synonymy, distribution, and conservation status. Key: †=extinct.

Testudines

Kingdom:Animalia
Phylum:Chordata
Class:Reptilia
Clade:Diapsida
Order:Testudines

Genus

Chelonioidea
(Sea turtles)

Cheloniidae	†Allopleuron Caretta †Carolinochelys Chelonia †Eochelone Eretmochelys †Gigantatypus †Glarichelys †Itilochelys Lepidochelys †Mexichelys †Miocaretta Natator †Pacifichelys †Syllomus †Tasbacka
Dermochelyidae	†Arabemys †Corsochelys †Cosmochelys Dermochelys †Eosphargis †Mesodermochelys †Psephophorus
	†Euclastes †Peritresius †Procolpochelys †Protosphargis †Puppigerus

Kinosternoidea

Dermatemydidae	Dermatemys
Kinosternidae	Claudius †Hoplochelys Kinosternon Staurotypus Sternotherus

Testudinoidea

Emydidae	†Acherontemys Chrysemys Clemmys Deirochelys Emys Actinemys Emydoidea Glyptemys Graptemys Malaclemys Pseudemys Terrapene Trachemys †Wilburemys
Geoemydidae	Batagur †Banhxeochelys Cuora Cyclemys Geoclemys Geoemyda Hardella Heosemys Leucocephalon Malayemys Mauremys Melanochelys Morenia Notochelys Orlitia Pangshura Rhinoclemmys Sacalia Siebenrockiella Vijayachelys
Platysternidae	Platysternon
Testudinidae	Aldabrachelys Astrochelys Centrochelys Chelonoidis Chersina Cylindraspis †Cymatholcus †Floridemys Geochelone Gopherus †Hadrianus †Hesperotestudo Homopus Indotestudo Kinixys Malacochersus Manouria †Megalochelys †Oligopherus Psammobates Pyxis †Solitudo Stigmochelys †Stylemys Testudo

Trionychia

Carettochelyidae	†Allaeochelys †Anosteira Carettochelys
Trionychidae	Amyda Apalone †Axestemys Chitra Cyclanorbis Cycloderma †Drazinderetes Dogania †Gilmoremys †Hutchemys †Khunnuchelys Lissemys Nilssonia Palea †Palaeoamyda Pelochelys Pelodiscus Rafetus Trionyx
	†Basilochelys †Sinaspideretes

Chelydridae	Chelydra †Chelydrops †Chelydropsis †Emarginachelys †Macrocephalochelys Macrochelys †Planiplastron †Protochelydra
†Nanhsiungchelyidae	†Anomalochelys †Basilemys †Jiangxichelys
†Protostegidae	†Alienochelys †Archelon †Atlantochelys †Bouliachelys †Calcarichelys †Cratochelone †Desmatochelys †Iserosaurus †Notochelone †Ocepechelon †Pneumatoarthrus †Protostega †Rhinochelys †Santanachelys †Terlinguachelys
	†Adocus †Argillochelys †Bashuchelys †Ctenochelys †Prionochelys †Toxochelys

Pleurodira

†Araripemydidae	†Araripemys
†Bothremydidae	†Araiochelys †Arenila †Azabbaremys †Bothremys †Cearachelys †Chedighaii †Chupacabrachelys †Eotaphrosphys †Foxemys †Galianemys †Ilatardia †Inaechelys †Itapecuruemys †Jainemys †Kinkonychelys †Kurmademys †Labrostochelys †Nigeremys †Phosphatochelys †Polysternon †Puentemys †Rosasia †Rhothonemys †Sankuchemys †Taphrosphys †Ummulisani †Zolhafah
Chelidae	Acanthochelys Chelodina Chelus Elseya Elusor Emydura Hydromedusa †Lomalatachelys Mesoclemmys Myuchelys Phrynops Platemys †Prochelidella Pseudemydura Rheodytes Rhinemys †Yaminuechelys
Pelomedusidae	Pelomedusa Pelusios
Podocnemididae	†Albertwoodemys †Bauruemys †Brontochelys †Caninemys †Carbonemys †Cerrejonemys †Cordichelys Erymnochelys †Lapparentemys †Latentemys Peltocephalus Podocnemis †Stupendemys
†Sahonachelyidae	†Sahonachelys †Sokatra

	†Caribemys †Caririemys †Tacuarembemys

Phylogenetic arrangement of turtles based onTurtles of the World 2017 Update: Annotated Checklist and Atlas of Taxonomy, Synonymy, Distribution, and Conservation Status. † = extinct.

See alsoList of Testudines families

Taxon identifiers
Actinemys marmorata	Wikidata:Q667848 Wikispecies:Actinemys marmorata BioLib:25032 BOLD:253605 CoL:9T2V EoL:1056841 GBIF:2442896 iNaturalist:73592 IRMNG:10476669 ITIS:668668 IUCN:4969 NatureServe:2.103571 NCBI:335395 Open Tree of Life:743507 Paleobiology Database:105181 RD:marmorata