California Tiger Salamander Sam Jones

Greg Damron © www.wildvinestudios.com

California Tiger Salamander, Sonoma County Distinct Population Segment

(Ambystoma californiense)

Description and Ecology

 

Brandon Amrhein © www.fws.gov 

The California Tiger Salamander is a large, stocky terrestrial amphibian (Ambystomatidae family) with a wide round snout and eyes that protrude from its head. Adults have black bodies with white or yellow markings and are anywhere between 16-24 inches long, while larvae are pale. They are reclusive in nature and spend up to 90% of the year underground living in the burrows of small mammals, but also have the second longest dispersal distance reported for any salamander (1,840 feet per year). While they live most of their lives underground, it is imperative that these burrows are near vernal pools or seasonal ponds as that is where these salamanders breed. The life cycle of the California Tiger Salamander is split into two phases; the aquatic life stage and underground life stage. As larvae in the aquatic stage these salamanders eat invertebrate prey such as phytoplankton, small crustaceans, and insects. Less is known about the underground life stage; however, adults likely eat crickets, moths and larger invertebrates as that is what is commonly found in burrows. The California Tiger Salamander of Sonoma County is a distinct population segment (DPS) as it is geographically isolated and genetically different from the Santa Barbara and Central California DPSs.

Geographic and Population Changes

The Sonoma County DPS is endemic to the Santa Rosa Plain and San Joaquin-Sacramento River valleys and foothills. Their historical range included the Plain and the Petaluma lowlands, totaling over 100,000 acres. Before human interference the Plain had numerous vernal pools and was ideal upland and aquatic habitat for this salamander. Sadly, by the mid 1990s, the vernal pool population was estimated to have been reduced by over 80%. Their current range is now limited to only about 18,000-20,000 acres of fragmented habitat.

Little is known about the historic population abundance of the California Tiger Salamander, due mainly to their reclusive nature and that individuals spend most of their lives underground. What is known, is that populations are typically small, with less than a few dozen breeding pairs. Populations with over 100 breeding individuals are extremely rare. This salamander experiences high variability in the number of breeding adults, as well as the number of larvae produced in a year. Research suggests that increasing variability could be, in part, due to the decreasing number of vernal pools as breeding grounds.

www.fws.gov

Listing Date and Type of Listing

Currently all California Tiger Salamanders are listed, but as three different entities; the Sonoma County DPS, the Santa Barbara DPS, and the Central California DPS. The Sonoma County DPS was listed as Endangered on July 22, 2002.

Cause of Listing and Threats to its Continued Existence

The primary cause of population declines, and listing is due to habitat destruction and fragmentation. Much of the area that is ideal habitat for this salamander has been altered by humans and used for urbanization or farming. The invasion of humans brought other things that currently affect these salamanders.

Humans introduced bullfrogs to the area for fish bait that eat the salamander larvae effectively bringing population growth to a halt. Rodent control in the area is a huge problem for the salamander for two reasons. First, the decreasing populations of ground squirrels reduces the number of burrow habitat for the salamanders and second, the poison used to kill the squirrels and other rodents seeps into the water and soil, and is absorbed by the salamanders’ permeable skin.

© Gary Nafis http://www.californiaherps.com

Description of Recovery Plan

The recovery plan for the Sonoma County DPS of the California Tiger Salamander focuses on minimizing habitat loss and fragmentation. The U.S. Fish and Wildlife Service plan to do this by purchasing 15,000 acres of breeding ponds and nearby land. The intent is to “preserve high-quality habitat that promotes connectivity and reduces fragmentation… [as well as] stop further development on those lands” (U.S Fish and Wildlife Service). The plan also states that it will restore breeding habitats, as well as reduce the risk of non-native predators and disease. The habitat restoration and protection is estimated to cost at least $379,608,000; this does not include proposed research into lesser known habitat areas.

www.fws.gov

What can you do?
After reading all of that now you might be wondering “What can I do?” The first step is getting informed, which you’ve already done by reading the information above! Information is power, and we can’t save a species that we don’t even know is endangered. Next, there are some simple things you can do to help the California Tiger Salamander. Don’t pour any harmful chemicals or drugs down the drain. Salamanders have permeable skin, meaning that whatever is in the water or soil surrounding them will be absorbed into their bodies through their skin. By reducing the amount of harmful substances in the earth we can reduce the contamination and disease to the salamanders. Another small act is to refrain from using rodenticides. Small rodents make burrows in the ground that are perfect habitat for the salamanders, reducing the number of small rodents reduces habitat for these adorable amphibians.

© Dante B. Fenolio www.arkive.org

If you want more information on the California Tiger Salamander, or want to get involved, check out these other resources!
Species Profile - California Tiger Salamander
Sacramento Fish and Wildlife Service - California Tiger Salamander
Santa Rosa Plain Recovery Plan
Summary of Santa Rosa Recovery Plan







Sources

Service, U.S. Fish and Wildlife. “California Tiger Salamander (Ambystoma Californiense).”Species Profile for California Tiger Salamander (Ambystoma Californiense), U.S. Fish and Wildlife Service, ecos.fws.gov/ecp0/profile/speciesProfile.action?spcode=D01T.

“California Tiger Salamander.” U.S. Fish and Wildlife Service, www.fws.gov/sacramento/es_species/Accounts/Amphibians-Reptiles/ca_tiger_salamander/.

“Recovery Plan for the Santa Rosa Plain.” U.S. Fish and Wildlife Service, U.S. Fish and Wildlife Service, 31 May 2016, Recovery Plan for the Santa Rosa Plain, https://ecos.fws.gov/docs/recovery_plan/06012016_Final%20Santa%20Rosa_RP_signed_1.pdf.