CaliforniaHerps.com

A Guide to the Amphibians
and Reptiles of California


Alien Species of Amphibians and Reptiles in California

(Also known as introduced species, exotic species, non-indiginous species, non-native species,
or invasive species (if they have been proven to be harmful.)






Report an Invasive Species
Sighting to the California
Department of Fish and Wildlife
Report a Nonindigenous
Aquatic Species to the USGS



observation link


Established in California

 

Not Yet Confirmed as Established in California

Reported in California but not yet
confirmed as established
Species formerly established in California,
but apparently no longer present
Feral alien pets sometimes
found in California
 
These are lists of alien species of amphibians and reptiles found in California.

- The first list shows established non-native amphibians and reptiles which have been introduced into California through the actions of humans. (Some of them may be "Invasive Species" which are threatening native wildlife, but I don't show that designation here.) All of these species have established self-sustaining breeding populations. Most of them have arrived recently, spread by humans either intentionally or accidentally. In some cases these established populations may prove to be only temporary and will eventually die out. If that happens they will end up in the section of formerly-established species.

- The second list shows non-native species that have been reported in the state as established but have not been officially documented and confirmed as being established in the state.

- The third list shows non-native species commonly kept as pets which are sometimes found in the wild in Calfiornia. They probably don't represent reproducing populations, but they could become established if enough of them escape into the wild.


The pet trade is often vilified as solely responsible for the spread of alien species, but many of the non-native species of herps that have become established in California did not originate through the pet trade. Some originated as stow-aways transported from outside the state, and others were accidentally or intentionally released from laboratories, the food industry, or when used as fish bait.

Released or escaped pet herps of almost any species are sometimes found in the wild, especially in heavily-populated areas, but these do not necessarily constitute an established population. See our separate page of Feral Pet Herps found in the state.

My intent here is to try to keep track of the established alien species which are the most common and widespread. There are certainly more species which have become established in small areas in California which are not on this list. (House Geckos living in pet stores, for example - it is doubtful these geckos have invaded the rest of the neighborhood so they can't really be considered established.) More species will probably become established in the state in the future, and some introduced populations will disappear due to competition, climate, disease, intentional eradication, or due to other causes.


Please contact me by email if you find any wild non-native amphibians or reptiles in the state. Send a picture if you can. I will try to contact somebody who is working to document them and to keep them from getting established.


The California Department of Fish & Game has an Invasive Species Program to prevent the spread of Invasive species and to reduce their negative effects.

Report an Invasive Species Sighting to the California Department of Fish and Wildlife


California Department of Fish and Wildlife information about how to prevent introductions of Invasive Species

You can look through their regulations regarding invasive species here and at Fish and Game Code Section 6400.
My interpretation is this: DON'T RELEASE ANY ANIMAL THAT IS NOT NATIVE TO CALIFORNIA in the water or on land.
It is also illegal to release native animals. See my information about the laws regarding captive native wildlife.

California Department of Fish and Wildlife .pdf About Problem Pets



Alien Species of Amphibians and Reptiles Established and Breeding in California

Alien Frogs Established in California
 
Lithobates (Rana) berlandieri - Rio Grande Leopard Frog  
Native to the southeast from the Atlantic to central Texas. Accidenatlly released near Yuma between 1965 - 1971, quickly spreading along the lower Colorado River area and the Imperial Valley. Range continues to expand.
Most likely introduced accidentally with fish plants from Texas or New Mexico.
frog picture
Lithobates (Rana) catesbeiana - American Bullfrog  
Native to the eastern and midwestern United States and southeast Canada. Introduced for food in the 1920's by commercial frog farmers due to its large meaty legs. Now established throughout most of the western United States and southwestern Canada.

This frog was included on the 2014 Global Invasive Species Database list of the 100 worst invasive alien species.
frog picture
Lithobates (Rana) sphenocephala - Southern Leopard Frog  
Most likely first introduced into the Santa Ana River basin in 1929 or 1930, probably as larvae that arrived with other imported Bullfrogs, fish, and crayfish from Louisiana. Now common in the Prado Flood Control Basin.

Xenopus laevis - African Clawed Frog  
Originally native to South Africa. Brought to the US in the 1940's and widely used for laboratory study and human pregnancy testing. Also a popular aquarium pet. Escaped and released laboratory animals and released pets were established in California primarily before being banned in the 1960s.

African Clawed Frog
Eleutherodactylus coqui - Common Coquí  
This frog is listed as established in several locations in Southern California, but there is not much information about where they are. The presence of this alien frog is more apparent than that of most invasives because their loud nocturnal calls are annoying and obviously out of place. Most likely, Coqui frogs, or their eggs, arrived in California stowed away in agricultural or other kinds of shipments from Hawaii, Puerto Rico, or other locations where they are established.

This frog was included on the 2014 Global Invasive Species Database list of the 100 worst invasive alien species.


I first received requests to identify coqui by sound during the summer of 2014 from people in San Diego and Los Angeles who were annoyed with the loud sound they heard all night, (one group of people thought was a bird calling) and wanted to find out what was making the sound and how to get rid of it. (These were just single frogs. Imagine how desperate people would get if there were many frogs calling.)


The California Department of Fish and Wildlife includes the Common coqui on their list of invasive species in California:

"A single coqui was collected from a private residence in Orange County in 2012 and was determined to have originated by “hitchhiking” on a tropical house plant. Subsequent inspections of the nursery from which the plant was purchased, in San Diego County, detected (heard) multiple calling males and resulted in the collection of one adult, two froglets, and a cluster of coqui eggs. Currently, that population appears to be confined to the single nursery site. However, in 2014, after a month of nightly calling, what homeowners in Ocean Beach (San Diego) thought to be a songbird was determined to be a coqui."


The SSAR Official Names List 7th Edition of 2012 also lists this frog as established in California:

"The Coqui is native to Puerto Rico, has been reported from four states, and is reported as established in California, Florida and Hawaii. It is widely established on Hawaii Island but is more restricted and the target of eradication efforts on the other Hawaiian Islands. Populations in California and Florida appear to be limited to nurseries (Dalrymple, 1994, Non-indigenous Amphibians and Reptiles in Florida in Schmitz, D. C. and T. C. Brown [eds.] An Assessment of Invasive Non-indigenous Species in Florida's Public Lands, Technical Rpt. TSS-94-100. Florida Department of Env. Protection, Tallahassee, FL., P; 67-78; K. Krysko, pers. comm.; D. Schnabel, pers. comm.) it is uncertain to what extent they are maintained by constant reintroduction, and they perhaps should not truly be considered established."


With the Coqui now established throughout the Hawaiian islands, California Department of Food and Agriculture inspectors are carefully inspecting all Hawaiian plant material for the frogs and their eggs, which are laid on leaves. They have already found frogs and their eggs in many shipments of ornamental plants from Hawaii. (James A. Bethke)

"Coqui frogs have been reported at Disneyland, Hermosa Beach and at nurseries" is listed as one of the highlights in a meeting of California Department of Food and Agriculture and California Department of Fish and Game [Fish and Wildlife] personnel 12/22/10 in Sacramento.

An ABC News report from 3/18/16 mentions a Beverly Hills Coqui whose calling neighbors thought was a broken house alarm prompting them to call the police, and a nursery in Torrance where Coquis appear to be established. They also mention that the tropical frogs are able to survive the semi-arid conditions of Southern California by living in areas that use sprinkler systems, such as nurserys and most homes in the area.


You can listen to the sound of a Coqui Frog recorded in Puerto Rico by Karen Cooper Here

You can also see and hear a Coqui Frog calling in this
YouTube Video


The California Department of Fish and Wildlife requests you take this action if you find a Common coqui:

"If this species is found (or heard) in California, do not release it. Immediately contact the CDFW Invasive Species Program to report your sighting at www.wildlife.ca.gov/Conservation/Invasives/report, by email to Invasives@wildlife.ca.gov, or by calling (866) 440-9530."


frog picture© William Flaxington

frog picture
© 2008 Dr. Peter Janzen
 
Alien Salamanders Established in California
   
Ambystoma mavortium (tigrinum) - Barred Tiger Salamander
 
Introduced into isolated locations in California, most likely through the introduction of larvae used as fishing bait that were accidentally released. Expanding irrigation in arid areas can help to encourage their spread.

 
Alien Lizards Established in California
   
Anolis carolinensis - Green Anole  
This species is native to the south and southeastern United States and is present and probably established at a number of locations in coastal Southern California. They probably originated as released pets, as they have been widely available in the pet trade, but it's also possible that anoles and their eggs have been transported in shipments from the Southeast.

Green Anole

Green Anole
Anolis sagrei sagrei - Cuban Brown Anole
 
I received reports with pictures of established populations of Brown Anoles on a one acre palm garden in Vista and at another location in Santa Ana. I contacted some Southern California herpetologists who went to the site and published a report, documenting the first state record of this species established in California in Herpetological Review 45(4), 2014, which you can see on the A. sagrei page.

I have received reports that a population of this lizard exists at a private residence and its surroundings in Palm Desert and another in Rancho Mirage. I have not been able to confirm these yet, but photographs show the species and the presence of several lizards indicates an established population.

I have received another report showing a neonate lizard found at a residence in Orange County.

The origin of these lizards is not clear - they might have been transported in agricultural shipments from Florida or Hawaii, or they might have originated from released pets.

Colorado Desert Fringe-toed Lizard
© Len Geiger
Aspidoscelis flagellicauda x Aspidoscelis sonorae Complex (Gila Spotted Whiptail x Sonoran Spotted Whiptail)
First reported seen in Irvine, Orange County, in 2014. They have been identified as a hybrid of two whiptail species native to Arizona, New Mexico, and Mexico. As of 2/21 they have been found only in Orange County and in northern San Diego County, and they appear to be spreading.

Found in landscaping and on parking lot asphalt. Described by Winkleman and Backlin as "...strongly acclimated to the urbanized environment and readily using spaces underneath concrete slabs for shelter." "Presumably introduced as a single released/escaped pet that subsequently underwent asexual reproduction and established a small, localized population." 

Striped non-native whiptails have also been found in Sacramento and in a few locations northeast of Sacramento, but it has not yet been determined if they are established or if they are the same mixed species as these.
Belding's Orange-throated Whiptail
  Adult, Orange County
© William Flaxington
Hemidactylus garnotii - Indo-Pacific Gecko (Fox Gecko, Garnot's House Gecko)  
This gecko is native to South and Southeast Asia, the East Indies, and many South Sea islands, including Northeast India, Bangladesh, Nepal, Myanmar, Thailand, the Malaysian Peninsula, Southern China, Taiwan, the Philippine Islands, Indonesia, New Guinea, new Caledonia, Polynesia, Fiji, Western Samoa, Vanuatu, the Cook Islands, and Tonga.
It has been established in Florida, Georgia, Hawaii, Texas and California, and in the Bahamas and Costa Rica.


Range in California

Documentation of this species in California was first published in December 2015.
(Gregory B. Pauly and Glen S. Yoshida. Herpetological Review 46(4), 2015.)
A population was found in Torrance, Los Angeles County, where it has been observed active during every month of the year since 2011. This population is apparently confined to one house lot.

It has spread to a few locations only so far (4/20) mostly in Orange County, with a few others in Lost Angeles and San Diego counties.
Mediterranean House Gecko
© William Flaxington

Mediterranean House Gecko
Hemidactylus mabouia - Tropical House Gecko
Also called: African House Gecko; Wood Slave, etc.

This species, originally from sub-Saharan Africa, was introduced to the Americas transported on ships involved with the slave trade. It has become well-established in much of Florida, the Carribean, Central America, and South America. In Florida, it has replaced the once-common Mediterranean Gecko, Hemidactylus turcicus.

It has also been found at several locations in Orange County and San Diego County. I am not yet aware of any published information reporting that they are established anywhere in California, but they certainly are. When last checked ( March, 2021) there are iNaturalist observations for H. mabouia from several locations in Orange County - Newport Beach, Santa Ana, Costa Mesa, and Tustin, and from locations in San Diego County at Chula Vista and San Diego, and another observation in Santa Cruz, with the earliest in San Diego in 2014. On the H.E.R.P. database, there are also several records from Orange County and one from San Diego County, with the earliest being from San Diego in 2013.

Wood Slave
Hemidactylus turcicus - Mediterranean Gecko  
Native to the Mediterranean region. This gecko has spread rapidly throughout world, probably through human transportation of lizards and their eggs in shipments of nursery plants, lumber, and other goods. A fairly recent arrival in California, continuing to expand its range. Now widespread in the southern part of the state and southern San Joaquin Valley.

Most likely this species originated from stow-aways transported into the state from Florida or Texas or other areas where they became established.
Podarcis siculus - Italian Wall Lizard  
A population of this Mediterranean lizard occurs in a suburban neighborhood in San Pedro, Los Angeles County.
The lizards were intentionally introduced in 1994 by someone who brought them from Italy.

Details are given in:
Deichsel, Guntram, Gary Nafis, and Jonathan Hakim.
Herpetological Review Volume 41, Number 4 - December 2010 P. 513-14

Another population was documented in San Marcos in September 2016. (Herpetological Review 47(3), 2016.)


Tarentola annularis - Ringed Wall Gecko (White-spotted Wall Gecko)  
In 2006 it was reported on the internet that there was a population of these geckos in Redlands, San Bernardino County.
"...there is a thriving population of Tarentola annularis in the downtown Redlands area. I've had reports of neonates from as much as 3 miles from the possible spot of the original introduction."

William Flaxington confirmed that they were there in 2007.
Jonathan Hakkim confirmed that they are still present in 2012.

In 2013 I gave William Flaxington's locality information to a Natural History Museum of L.A. County herpetologist who published the first documentation of the species in California in September, 2014. (Herpetological Review 45(3), 2014)

The species Tarentola annularis - Ringed Wall Gecko, is listed on the 2008 SSAR Alien Species list as native to northern Africa and established in Florida.

The most likely origin of these geckos is from escapees at a pet store.

San Francisco Alligator LizardAdult, Riverside County
© William Flaxington
Tarentola mauritanica - Moorish Gecko
 
Native to Mediterranean countries, found in isolated localities in California. Released or escaped pets are most likely the origin. The extent of the establishment of this species is not well known.

Reported as introduced and established in San Diego County, California.
(Mahrdt, 1998, Herpetol. Rev. 29: 52)

I have also received a report that a population of these geckos inhabited a building in Hanford years ago, and might still be there.

These geckos probably orinated in the state from intentional or accidental releases of pets.
Moorish Wall Gecko© Monte Lininger
Trachylepis Quinquetaeniata - African Five-lined Skink  
An established population of this species was first recorded in Glendora in eastern Los Angeles County in 2018 after being reported on iNatualist. The species is found in the reptile trade. The skinks in the original population in Glendora are thought to be derived from skinks kept by a reptile dealer living in the neighborhood, who imported some of them from Egypt in September 2014. Other exotic reptiles have been observed roaming free in the neighborhood, too. Residents report that there was a rapid population increase of African Five-lined Skinks in the summer and fall of 2018.

(Gregory B. Pauly and Patrick D. Gavid. Geographical Distribution Note. Herpetological Review 50(1), 2019)

The origin of other skinks found the general area is not known, but they could indicate that the original population has spread rapidly.
African Five-lined Skink
Adult male, St. Lucie County, Florida
Trioceros jacksonii - Jackson's Chameleon  

Native to East Africa. In California, Jackson's Chameleons have been introduced into San Luis Obispo, Los Angeles, and San Diego Counties. (McKeown, 1997 Bull. Chicago Herpetol. Soc. 32:101.) Locations include Morro Bay, Laguna Beach, and possibly the Palos Verde Peninsula.
Most likely, these lizards originated from released pets. Those in Morro Bay originated from the accidental release of ten captive animals in 1981.

 
Alien Snakes Established in California
   
It is unlawful to import, transport, or possess any Watersnakes of the genus Nerodia in
California except under permit issued by the California Department of Fish and Wildlife.
(California Code of Regulations, Title 14, Excerpts, Section 671)


The California Watersnakes Site reports on news, publications, and
sightings related to non-native watersnake species (Nerodia) in California.

If you see a watersnake in the wild in California at a location not mentioned on the
California Watersnakes Site, please report it to California Nerodia Watch at iNaturalist.

(Don't confuse Watersnakes (Nerodia) with native California gartersnakes. Most gartersnakes
have stripes on the sides and sometimes on the back. Watersnakes have no stripes.)

 
Nerodia fasciata - Southern Watersnake  
Native from the southeast into central Texas.

Established in at least three locations in California, most likely originating from intentionally or accidentally released pets.

1 - Established in and around Lake Natoma in the city of Folsom, Sacramento County, most likely from escaped or released pets. First documented in 1992 in Folsom.
See: Stitt, Balfour, Luckau, Edwards - U.S.Fish and Wildlife Service Report, April 2005.


2 - Established at Lake Machado in Harbor City, Los Angeles County.
Watersnakes in Harbor City have been identified as Nerodia fasciata pictiventris - Florida Watersnake.
(2006. Herpetol. Rev. 37:363).

According to Michael Fuller of the Nerodia Working Group, a reproducing population of N. fasciata has existed in Harbor City in Los Anageles for several years. While the snakes key out to N. f. pictiventris morphologially, preliminary mDNA results (as of 9/08) suggest that they are Nerodia clarkii, or possibly hybrids of N. clarkii and N. f. pictiventris. The habitat is a freshwater lake, typical of that used by N. fasciata, while N. clarkii typically inhabit brackish waters.

Biologists from the USGS and CDFW with authorization from the LA Dept. of Parks and Recreation have made efforts to eradicate Nerodia from the lake. In 2010 approximately 300 Florida watersnakes were trapped and removed. Necropsies on the snakes performed by biologists with the USGS, the US Fish and Wildlife Service, and UC Davis, found no remains of native species in their digestive tracts. Instead, the watersnakes were found to prey mostly on other invasive species found in the lake. According to USGS snake ecologist Robert Reed, young snakes prey mostly on nonnative mosquito fish, while older snakes prey on bullfrogs, and bullfrog tadpoles. The ongoing effort to clean up the lake and improve the water quality will increase the food source for the snakes and won't reduce their number. Reed says that the lake would have to be drained for at least a year in order to get rid of the source of food for the watersnakes, which would be the only sure way to get rid of the snakes.

LA Times 6/11/16


3 - In October 2015 state biologists confirmed the presence of southern water snake (Nerodia fasciata) at the Laguna Dam, Senator's Wash, and potentially nearby Mittry Lake, northeast of Yuma Arizona along the Colorado River at the border of California and Arizona. These snakes may have been introduced as released pets, but there is also a chance that they were brought to the area concealed in equipment that was brought in from the southeastern U.S. to a nearby U.S. Army base in Arizona.

snake

Southern Watersnake
Nerodia sipedon - Northern Watersnake  
According to Michael Fuller of the Nerodia Working Group, and my own observations, a population exists in the vicinity of Roseville, Placer County, which is fairly close to the Folsom population of N. fasciata.
These snakes most likely originated from intentionally or accidentally released pets.
snake
Indotyphlops braminus - Brahminy Blind Snake  
Native to South Asia and introduced around the world. First reported from Chula Vista in Herp Review, December 2010. Apparently spreading around Southern California. These snakes most likely originated as stow-aways in the soil of nursery plants from areas where they are established, such as Florida and Hawaii.

snake
 
Alien Turtles Established in California
   
Chelydra serpentina - Snapping Turtle  
Introduced into a number of isolated localities in the state, probably as a result of the release of unwanted pets. May not be breeding in all locations.

Eastern Snapping Turtle
Chrysemys picta bellii - Western Painted Turtle  
Established in many locations in ponds throughout the state, especially in the coastal south, probably as a result of the release of unwanted pets. Once thought to be native to extreme northern California.

Western Painted Turtle
Trachemys scripta elegans - Red-eared Slider  
Native to the south and midwest, from eastern New Mexico north into Chicago and south to the Gulf Coast of Alabama and Georgia. Found throughout California. A common pet turtle. The release of unwanted pets is largely responsible for the wide introduction of this species in California.

This turtle was included on the 2014 Global Invasive Species Database list of the 100 worst invasive alien species.
Red-eared Slider
Apalone spinifera emoryi - Texas Spiny Softshell  
Native to Texas and New Mexico. Probably first introduced into the Colorado River system, but I have not found out how or why. Now ranges throughout the Colorado River and the Imperial Valley and in other Isolated populations, including several locations in San Diego County.
















 

Alien Species of Amphibians and Reptiles Reported in California
but Yet Not Confirmed as Established


Below are herps that are not yet on the SSAR  Alien Species list of herps found in California and they are not yet on my state list either.


Please email me if you have any pictures or additional information about any of these species or any other alien herps in California.


Many non-native amphibians and reptiles have escaped into the wild in California. Alligators and Caiman occasionally show up in lakes and ponds and the press usually makes a big fuss over them. Most urban lakes contain a number of exotic species of turtles. (Jeff Lemm, in his Field Guide to the Amphibians and Reptiles of the San Diego Region, quotes biologist Mark Jennings, who has extensively surveyed Caifornia for amphibians and reptiles, as stating that there are "roughly 30 species of exotic turtles found in southern California's waterways, although not all of these are established."

There are certainly many more alien species than are covered here that have entered the wild in the state, but these are typically isolated instances and do not necessarily represent breeding populations, so they are not considered to be established non-native or exotic species, and they are not listed here. See the Escaped Pet Herps page to see some of those that have been reported to me.

Alien Lizards Possibly Established in California, but Not Yet Documented
   
Anolis equestris - Knight Anole (Cuban Knight Anole)  
There is an internet rumor that populations of these Cuban lizards occur in San Diego County. They have been established in Florida and Hawaii.

Wickipedia
lizard
© John Sullivan
Chamaeleo calyptratus - Veiled Chameleon  
I have been informed that a population of this species native to the Arabian Peninsula was established at a location in San Diego County in the early 2000's and may still be there and could be breeding. They originated from the escape of a captive collection. Attempts to re-locate them have apparently failed, so they may no longer occur at the lcoation.

Wickipedia
lizard
© Dave Shaw
Cyrtopodion scabrum - Keeled Rock Gecko

(also known as: Bow-footed Gecko, Rough-tailed Gecko, Rough Bent-toed Gecko, Rough-tailed Bowfoot Gecko, Common tuberculate Ground Gecko, and Keeled Gecko.)
This species is endemic to Africa, the Middle East, and Western Asia, found from Egypt east to Pakistan and northwest India and north to southern Turkey.

It has been introduced into Galveston, Texas, into Arizona, mostly in the greater Phoenix area, and into Nevada, mostly in the greater Las Vegas area.

It has also been found in California (as of 1/21) at Fort Irwin in San Bernardino County, where it was probably a stowaway on a military airplane returning from the Middle East, and near Death Valley in Inyo County, where it is thought to have been established through shipments transported from Las Vegas.

The species is comprised of males and females. It favors dry rocky desert areas in its native habitat, and is commonly found in and around human structures where it is a nocturnal wall climber, often seen under electric lights at night hunting flying insects. In Galveston Texas, where the gecko has been seen since 1983, it appears to have displaced the Mediterranean Gecko which was formerly found there.

Wickipedia
lizard
lizard
Adult, Inyo County
© 2021 Elliot Jaramillo
lizard
Adult, Inyo County © 2021 Elliot Jaramillo
lizard
Adult Inyo County © 2021 Elliot Jaramillo



Furcifer pardalis - Panther Chameleon  
There is an unconfirmed internet rumor that populations of these chameleons from Madagascar occur in San Diego County. This seems unlikely as there are not any established populations yet in Florida or Hawaii.

Wickipedia
lizard
© John Sullivan
Hemidactylus frenatus - Common House Gecko
Also called: Asian House Gecko.

Wickipedia

This gecko, originally from Southeast Asia, has been found in Garden Grove in Orange County (Natural History Museum of Los Angeles County specimen 2/14/12) but I am not yet (2/21) aware of any published information reporting that they are established in California. I have also received a personal report of an established population of some species of house gecko in Westchester Los Angeles which might be this species. These records may or may not indicate established populations. There are also some records on iNaturalist from Baja California near the Calfornia border.

H. frenatus has become established all over the world, including the United States where (so far) it has been found in North Carolina, Arizona, Hawaii, Florida, Georgia, Texas, New Mexico, Oklahoma, Arkansas, Mississippi, Louisiana, and Alabama, Tennessee, and California. (according to Wickipedia on 6/26/17).

Common House Gecko
Adult, Florida
Adults, Florida

Hemidactylus platyurus - Flat-tailed House Gecko
Also called: Asian Flat-tailed House Gecko; Flat-tailed Gecko; Asian House Gecko; Frilled House Gecko.

Originally from Southeastern Asia and Southern Asia.

Wickipedia

I am unaware of any published documentation of any California breeding populations for this species yet (2/21)  so I have not added it to my state list yet, but it seems to be established. It has been found in several locations in coastal southern California, including:

San Diego County

- A breeding population has been reported at the San Diego Zoo. There is an iNaturalist record for the species, with a photo and a comment from Greg Pauly, Associate Curator of Herpetology at the Natural History Museum of Los Angeles County, who states: "There is a known population of this species established at the Reptile House." There is also a specimen record in the NHMLA from the Reptile House.

Orange County

- There is a record for one specimen collected in Santa Ana in 2016 in the Natural History of Museum of Los Angeles County.
There are also several specimens in the NHMLA collection from Orange County with no specific location given, and a couple of iNaturalist observations from Orange County.

Los Angeles County

- There are iNaturalist observations from Los Angeles and a specimen in the HNMLA collection with no specific location given.

Mediterranean House GeckoAdult, Orange County
© William Flaxington
Bearded Dragon - genus Pogona  
These common pet lizards show up occasionally just about anywhere after escaping or after their owners dump them when they are no longer wanted. In February 2016 I received a report that there is a feral population of these lizards in Tehachapi and nearby Bear Valley, but I have not seen any published confirmation of this yet.

Wickipedia
lizard
   
Alien Turtles Possibly Established in California, but Not Yet Documented
 
Geochelone pardalis - Leopard Tortoise
A population of breeding Leopard Tortoises has been reported at Mission Trails Park in San Diego County. These tortoises, originally from Africa, are common pets. I have misplaced the source of this report, but Benjamin Lowe wrote in to tell me that "It comes from a list of the park's reptiles and amphibians that once graced the park's website and no longer seems to exist." My search of the park website also failed to find a herp species list, but if they were on the old list, it follows that they were most likely present at one time in the park.

Wickipedia
lizard
© John Sullivan
Malaclemys terrapin - Diamondback Terrapin
Abandoned pets still show up occasionally in brackish California waters, and it's possible some are reproducing.

Diamond-backed Terrapins are found all along the east coast of the United States, living in salt marshes and brackish water. They became famous as one of the best tasting turtles for making turtle soup, and were so abundant and easy to catch that huge numbers were harvested and sold until by the 1900s populations were becoming greatly reduced. They are currently (2020) classified as Near Threatened by the IUCN because its population is decreasing across much of its range, but they are also listed as endangered in Rhode Island and threatened in Massachusetts. (Wickipedia.)

Because of their popularity, attempts were made to introduce Diamondback Terrapins into the San Francisco Bay to provide a source of food, but these attempts failed:

According to Brown, P. R. (1971). "The story of California diamondbacks". Herpetology. 5: 37–38, in 1896, an unknown person introduced 129 turtles in the San Francisco Bay region. The turtles did not survive. In 1943 the Consolidated Sportsmen's Clubs of the Peninsula provided funding for an attempt to establish Diamondback Terrapins into the San Francisco Bay. Two groups of turtles, raised by the U.S. Fish and Wildlife Service in North Carolina, were planted on a small, unnamed island in the southern S.F. Bay in May, 1943 - 485 yearlings at one spot, and 77 adults (52 females and 25 males) at a second spot. The California Department of Fish and Game then enacted a law that made it unlawful to take Diamondback Terrapins at any time in the state. But even though there appeared to be plentiful food and suitable habitat on the island, a search of the island in October 1943 failed to find any signs of terrapins. The turtles had disappeared and were apparently never established in the bay.

Also see: California Fish and Game Vol. 30 No. 2, April 1944, pp. 101-102, "Diamond-back Terrapin Introduced into California."
Red-eared Slider
© 2011 Todd Pierson










lizard© Henry Hwang, Vollmar Natural Lands Consulting
In June, 2020, while doing a survey for pond turtles for Vollmar Natural Lands Consulting in the San Francisco Bay Delta north of Concord, Henry Hwang discovered a gravid Diamondback Terrapin (shown here below and to the right) attempting to dig a nest and lay eggs on the side of a railroad berm near a brackish salt marsh. The turtle was removed before laying her eggs, but this reproductive female could represent a breeding population. There is no way to know for certain until more terrapins are found, because she could have been a pet that was abandoned while gravid.
lizard lizard lizard
The four terrapin and terrapin habitat photos above are all © Henry Hwang, Vollmar Natural Lands Consulting.
 
Alien Snakes Possibly Established in California, but Not Yet Documented
   
Beauty Rat Snake - ake Beauty Snake - Orthriophis taeniurus  
More than one specimen of these snakes has shown up in Contra Costa County and in Santa Ana but it is not known if they are breeding in either location.

Wickipedia
snake
© Gailene Nelson
   
Alien Crocodilians Possibly Established in California, but Not Yet Documented
   
American Alligator - Alligator mississipiensis
Every once in a while the press goes crazy about a feral pet alligator that was found in a pond or lake in California. A good example is "Reggie," an alligator that inhabited Lake Machado in Los Angeles County (Wickipedia Article) before it was captured and brought to the Los Angeles Zoo in 2007.

Recently I was made aware that it's possible that more than one Alligator has been found in the Prado Flood Control Basin in Riverside and Orange Counties. The species is listed in a 2006 study of aquatic predators in the Prado Wetlands as having been found there, and I am told that the skin of a large alligator that was killed there is mounted in the Duck Club office at Raahauge’s Shooting Enterprises in Norco. It's also possible that the alligator on display was the only one found there and it is the only reason for the species being listed in the report.
(Let me know if you know any more details about alligators at the Prado Wetlands.)

Wickipedia

   
Alien Frogs Possibly Established in California, but Not Yet Documented
   
Osteopilus septentrionalis - Cuban Treefrog  
I list this frog here because although they are kept as pets and Cuban Treefrogs found in California might be escaped pets, they have also been found on nursery plants which may have been imported from nurseries in Florida where this frog is an established invasive species. The transportation of Cuban Treefrogs and their eggs on nursery plants is a possible method of introduction of this species into the state, though it is not known if they can survive in the dryer, less humid environment.

In February 2021 there are now only two iNaturalist records for this species from Newport Beach and San Diego. Previous records from Fresno and Ramona have been removed.

Wickipedia

Cuban Treefrog









 

Status in Doubt: Amphibians and Reptiles Formerly Established in California, but Apparently No Longer Present

 
Alien Snakes No Longer Established in California
   
Nerodia rhombifer - Diamond-backed Watersnake
 
This snake, native to the Southeast and farther south in eastern Mexico, was introduced to Lafayette Reservoir in Contra Costa County. First observed in the late 1980's, the population reached high densities in the early 1990's, bringing complaints from fisherman and other visitors who believed the non-native snakes were eating the reservoir's fish, frogs and turtles (which mostly consist of non-native stocked fish, non-native American Bullfrogs, and non-native Red-eared Sliders.) In 1996 a contract was awarded to a wildlife control company to begin to control the snake population. Just as efforts were begun to increase the control effort in December, 1997, large numbers of dead watersnakes and turtles were observed. The cause of the die-off is unknown, but dissected snakes were found to contain a respiratory tract fungus. An abnormally wet and cold El Nino weather system has been indicated as a possible cause for the outbreak. No watersnakes have been confirmed at Lafayette Reservoir since late 1999, but sightings are occasionally reported, and the population may still continue to hang on there in low numbers.

Source: Stitt, Balfour, Luckau, Edwards - U.S.Fish and Wildlife Service Report, April 2005.

Wickipedia

Northern Diamond-backed Watersnake
   
Alien Lizards No Longer Established in California
   
Ctenosaura hemilopha - Spiny-tailed Iguana  
According to Robert Stebbins in California Amphibians and Reptiles, 1972, this species, native to southern Baja California, was once present in "...Fullerton, Orange County; some indications that it may be reproducing there."  There is no recent information that they still occur in the area.

Wickipedia
lizard
Gehyra mutilata - Stump-toed Gecko  
A naturalized population of Gehyra mutilata was reported in San Diego in 1982 by Smith & Brodie, and mentioned on the 2000 S.S.A.R. Herpetological Circular No. 29 scientific and common names list: "This species is also established in San Diego, California (Smith and Kohler, 1978, Trans. Kansas Acad. Sci. 80: 1–24 and references therein) " The population is no longer thought to be extant, possibly a result of their inability to survive cold winters.

Wickipedia
lizard© William Flaxington
Sceloporus cyanogenis - Blue Spiny Lizard  
(= Sceloporus serrifer)

According to Robert Stebbins in California Amphibians and Reptiles, 1972, this species, native to southern Texas and northeastern Mexico, could be found at the base of the Palms to Pines Highway above Palm Springs. Whether or not it was established and breeding was unknown. It does not appear that they remain in the area.

Wickipedia
Blue Spiny Lizard
   
Alien Turtles No Longer Established in California
   
Gopherus berlandieri - Texas Tortoise  
According to Robert Stebbins in California Amphibians and Reptiles, 1972, this species, native to southern Texas and northeastern Mexico, could be found occasionally in the desert where it was released as an unwanted pet. Whether it became established anywhere was then unknown, but it is doubtful now that they are established anywhere in the state.

Wickipedia
Texas Tortoise
Malaclemys terrapin - Diamondback Terrapin  
Attempts were made to establish Diamondback Terrapins in the San Francisco Bay, but they did not succeed.
See my notes above.
Red-eared Slider
© 2011 Todd Pierson
   

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