Biological Diversity


"Don't hate me because I'm beautiful, dahlin'..."

This image courtesy
http://www.biologicaldiversity.org/swcbd/species/ctigersal/


Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Caudata
Family: Ambystomatidae
Genus: Ambystomata

Species: Californiense


Distribution of Ambystoma californiense
Image courtesy http://www.npwrc.usgs.gov/narcam/idguide/acalif.htm

 

Conservation Organizations

Frogs.org
This is the website of Amphibian Conservation Alliance, an education organization dedicated to the preservation of amphibian populations. Despite the name, the organization represents all kinds of amphibians. Clicking here will take you to an article in the website specifically about Ambystoma californiense.

FrogWeb
This website examines recent amphibian decline, giving the issue thorough examination. It looks at the problem and discusses the possible reasons. The sections on habitat loss and invasive species are especially relevent to our species.

AmphibiaWeb
This is the most comprehensive website available on the topic of amphibians. It discusses every species of amphibian individually, including conservation status. It also discusses the widespread problem of amphibian decline


Some Fun Salamander Links!

Image courtesy http://www.thenetnet.com/

Autodax: Salamander Feeding
This a neat collection of movies showing various species of salamanders eating. The movies take some time to load, but they're worth it!

Neuromechanical Simulations of Salamander Locomotion
The author of this site created realistically moving computer simulated salamanders. An example is shown below.


"Hey man! I'm walkin' here!"


Cool Cali Tiger Salamander Pics!!!


"I'm blue, da ba dee, da ba die..."
image courtesy of http://elib.cs.berkeley.edu/imgs/128x192/0000_0000/0901/0483.jpeg



"What chu lookin' at?!"

Image Courtesy of http://www.biologicaldiversity.org/swcbd/species/ctigersal/


"Put me down, already...you smell!"
Image courtesy of http://desfbay.fws.gov/TigSalam.htm

Image courtesy of
http://www.rain.org/~audubon/sbasspecies.html


"Hey there baby...what's your sign?"
Image courtesy of http://www.metroactive.com/papers/metro/11.24.99/gifs/species2-9947.jpg

Ambystoma californiense

California Tiger Salamander

Introduction

Distribution: The California Tiger Salamander makes its home, not surprisingly, solely in California. This species' distribution is limited to the Central Valley and the adjacent foothills, in Coastal Ranges, and the Santa Rosa Plain in Sonoma County (Center, 2001).
Habitat: The California Tiger Salamander lives, primarily, in underground refuges, abandoned rodent burrows in grassland or oak environments. During the breeding season, the California Tiger Salamander migrates to nearby vernal/seasonal ponds (Center, 2001).
Physical Characteristics: A. californiense is a rather bulky amphibian. While the average adult may range in length from 4 to 6.5 inches, there have been findings of this species that have grown to roughly 9 inches in length (Northern, 2001). They are of a unique color pattern, similar to the unique fingerprints in human beings. They are primarily dark (black or royal blue) with light, creamy-yellow spots. Their bellies are grey (Northern, 2001). Recent observations have shown that the males have predominantly longer tails than the females (Edwards, 2001).
Reproduction: In order for successful breeding to occur A. californiense mates and deposits its eggs in vernal pools. The migration to the vernal pools happens during California's winter rainy season. A single female can lay approximately 400 to 1300 eggs per season. The justation period of the eggs lasts about 10 to 14 days (Center, 2001). In late spring or early summer, the postmetamorphic juveniles leave the breeding sites at night.


A vernal pool, the kind California Tiger Salamanders use to deposit their eggs.
Image courtesy of http://science.kennesaw.edu/~mlaposat/amphib/wwphibs/

Developement and Lifespan: The larvae of the California Tiger Salamander feed primarily on algae, small srustaceans and mosquito larvae. Larger larvae feed on aquatic insects, assorted invertebrates, and small tadpoles of various Pacific Tree Frog species (Ceneter, 2001). Larvae require a full 3 to 4 months to complete their metamorphosis (Northern, 2001).


"Those Pesky Californian Tiger Salamanders, they keep eating my babies! Ribbit!"
Image courtesy of http://elib.cs.berkeley.edu/imgs/128x192/8253_3202/3493/0074.jpeg

Behavior: Not much is actually known with the regard to A. californiense's behavior due to the fact that it spends the majority of its life in underground refuges and burrows. The amphibian will not breed until it reaches maturity, perhaps 4 to 6 years of age. It is also known that slightly less than 50% of all California Tiger Salamanders usually will not breed more than once in their entire life. This may be due to instabilities in weather patterns during the winter-rainy season, for example the climate might be too dry and the conditions would be wrong for breeding (Kucera, 2001).

Conservation Status

Ambystoma californiense is listed on the United States Endangered Species Act list as Endangered. On the ICUN Red List, it is VU A2c, which means it is Vulnerable, and that a population reduction estimated of 20% or more is expected in the next 3 generations or 10 years, mainly due to the decline of habitat quantity and quality.

Conservation Issues

Habitat Loss and Fragmentation: Due to human expansion, urban development in California has caused drastic reduction of suitable habitat for A. californiense (Natureserve, 2001). Conversion of land into agriculture has also depleted former breeding sites of this salamander. Once moderate grazing areas where vernal pools existed, are now heavily farmed fields (Natureserve, 2001). In addition to habitat loss, the fragmentation of habitats along the coast of California are beginning to effect the movement of california tiger salamanders to more suitable breeding areas (LaMonte, 2001). Vehicular-related mortality to the salamander populations further support fragmentation and loss of mobility (Center, 2001b; Natureserve, 2001). Click here for a map of known A. californiense range within California counties (Center, 2001). Click here for a comparison A. californiense historic and current ranges within Sonoma County, CA (Center, 2001).

Introduced Exotic Predators and Aliens: Predatory fish, such as the Mosquitofish (Gambusia affinis), introduced to help control mosquito levels, threaten the stability of california tiger salamander population (LaMonte, 2001). Pesticides may also be contaminiating food sources in vernal pools. Other introduced predators, such as bullfrogs and crayfish, are threatening this endemic species by occupying their breeding grounds (Lardner and Sidenmark, 1996; NatureServe, 2001). The Red Eye Bass, pictured below, was introduced in the 1960s to stock California waters for sportfishing, but its species has negatively affected A. californiense (Fuller, 2001). Also a threat are salamanders released into the wild, thought to be owned as pets, which breed with A. californiense. These aliens threaten to compromise Tiger salamanders' genetic composition, as well as spread new diseases (Center, 1999; NatureServe, 2001).


A Red Eye Bass, one of the invasive species thought to be partially responsible for the decline of Ambystoma californiense
Image courtesy
http://nas.er.usgs.gov/fishes/accounts/centrarc/mi_coosa.html

Global Trends and Future Management: It is estimated that globally, A. californiense has been eliminated from 55-58% of historic breeding sites, and that worldwide 75% of historical vernal pools habitats suitable for breeding have been destroyed (Natureserve, 2001). While these alarming statistics seem to point towards a rapid extinction rate, the ICUN Red List only rates A. californiense as Vulnerable. This may be in part to areas of California that still harbor the salamander; areas where the salamander is deemed as locally common. The threat of fragmentation, however, significantly impacts the future success of this endemic species. Local management methods such as builiding underroad tunnels to increase salamander mobility have been proposed. Maintenance of water levels in vernal pools during the summer would also aid in complete larvae metamorphosis, ensuring the success of future generations (Natureserve, 2001). Conservation efforts such as these will help to limit anthropogenic extinction, and hopefully ensure the survival of biodiversity.

Literature Cited

Center for Biological Diversity. 2001 November 13. California tiger salamander (Ambystoma californiense).
http://www.biologicaldiversity.org/swcbd/species/ctigersal/ Accessed 2001 November 13

Center for Conservation Biology. Stanford University. 1999. California Tiger Salamander Ambystoma californiense http://ccb.stanford.edu/sunri/cts1-1.html Accessed 15 November 2001.

Center for Conservation Biology. Stanford University. 2001. http://www.stanford.edu/group/CCB/Biodiv/CTS.html Accessed 2001 November 15.

Edwards, D. San Francisco Bay National Wildlife Refuge. 2001 August 26. California tiger salamander. http://desfbay.fws.gov/TigSalam.htm Accessed 2001 November 13.

Fuller, P. Florida Caribbean Science Center, United States Geological Survey. 2001 June 15. http://nas.er.usgs.gov/fishes/accounts/centrarc/mi_coosa.html Accessed 2001 November 15, 2001

Kucera T. California Wildlife Habitat Relationships System California Tiger Salamander Ambystoma californiense. http://www.dfg.ca.gov/whdab/cwhr/A001.html Accessed 2001 November 13.

LaMonte, G. Amphibia Web. April 18, 2001. Ambystoma Californiense California Tiger Salamander. http://elib.cs.berkeley.edu/photos/fauna/sci-Amphibian.html Accessed 2001 November 15

Lardner, B., Sidenmark, J. Aliens Exterminate Amphibians. 1996, May. http://www2.open.ac.uk/biology/froglog/froglog-17-2.html Accessed 2001 November 15.

NatureServe: An online encyclopedia of life 2001. Version 1.5. Arlington, Virginia, USA: Association for Biodiversity Information. Available: http://www.natureserve.org/ Accessed 2001 November 15.

Northern Prairie Wildlife Research Center. 2001 September 6. California tiger salamander. http://www.npwrc.usgs.gov/narcam/idguide/acalif.htm Accessed 2001 November 13.

Author: Justin Fuller, Molly McMahon, Dara Wentworth
Date Created: 31 October 2001
Last Revised: 15 November 2001


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This website is part of a Biology 26 class project on the conservation of global biodiversity.


Earlham Biology Department Biology 26: Biological Diversity

Copyright -2001 Earlham College. Revised 1 October 2001. Send corrections or comments to mcmahmo@earlham.edu