Palm Canyon habitat, access courtesy of Eddie Konno CDFW
In the spring of 2006 I was allowed to hike down into a protected canyon to assist the California Department of Fish and Game in a survey for Desert Slender Salamanders. When we arrived, we could see where water from an unusually heavy rain storm the previous October had poured down the cliff above the canyon and washed away a great deal of vegetation, including the area where the salamanders have been found. In a casual search under available cover, we were unable to locate any salamanders, but Desert Slender Salamanders most likely continue to survive in this location since they have been subjected to such flooding over the millenia, (including a severe storm in 1976.)
Desert surrounding the restricted canyon habitat, Riverside County.
Adults are 1 1/4 - 2 inches long (3.1-5 cm) from snout to vent.
A fairly broad-headed and long-legged slender salamander with a relatively short tail and 16-19 costal grooves (usually 18).
There are 3.5 - 6.5 costal folds between adpressed limbs.
Short limbs, a narrow head, long slender body, very long tail, and conspicuous costal and caudal grooves give this species the worm-like appearance typical of most Slender Salamanders.
There are four toes on the front and hind feet, which is also typical of Slender Salamanders.
(Other California salamanders have five toes on the hind feet.)
Color and Pattern
Adults have a pale grey, white or pink coloration dorsally due to a suffusion of silver or brassy flecks.
The underside of the tail is paler than the dark belly.
Young lack the speckling of the adults.
Life History and Behavior
A member of family Plethodontidae, the Plethodontid or Lungless Salamanders.
Plethodontid salamanders do not breathe through lungs. They conduct respiration through their skin and the tissues lining their mouth. This requires them to live in damp environments on land and to move about on the ground only during times of high humidity. (Plethodontid salamanders native to California do not inhabit streams or bodies of water but they are capable of surviving for a short time if they fall into water.)
Plethodontid salamanders are also distinguished by their naso-labial grooves, which are vertical slits between the nostrils and upper lip that are lined with glands associated with chemoreception.
All Plethodontid Salamanders native to California lay eggs in moist places on land.
The young develop in the egg and hatch directly into a tiny terrestrial salamander with the same body form as an adult.
(They do not hatch in the water and begin their lives as tiny swimming larvae breathing through gills like some other types of salamanders.)
Although it occurs amidst one of the harshest climates in the world, B. m. aridus has been found during every month of the year - even in the middle of summer - which indicates that they are active whenever surface conditions are favorable.
Most of the specimens of this salamander exhibited a defensive behavior unique to slender salamanders when they were uncovered in the field. They coiled their body while elevating their tail. The combination of these two behaviors has not been observed in any other species of slender salamander.
Diet and Feeding
Most likely eats a variety of small invertebrates. Salamanders have been observed feeding at night capturing small insect with their projectile tongue.
Reproduction is terrestrial.
Little is known of the reproductive habits of this salamander.
Females of other Batrachoseps species lay eggs in moist places on land.
It is presumed that eggs are laid in deep moist limestone crevices.
Young develop completely in the egg and hatch fully formed.
In Hidden Palm Canyon, B.m. aridus inhabits a moist cliff and the talus beneath it, as well as associated springs at the oasis. The cliff has a year-round seep covered in Maidens-Hair Fern, and shaded by California Fan Palms and Willow trees.
The habitat surrounding the canyon is dry sonoran desert scrub.
Salamander sites are shaded and do not get much direct sunlight.
Endemic to California. B.m.aridus has one of the most limited geographic distributions of any North American amphibian.
So far it is only known from two localities on the east slope of the Santa Rosa Mountains: Hidden Palm Canyon (a tributary to Deep Canyon) at an elevation of 2,800 ft., (850 m) and Guadalupe Canyon, about 4.5 miles - 8 km (by air) to the south-east. The numbers of salamanders found at a given locality within Guadalupe Canyon have been fewer than those found in Hidden Palm Canyon.
Notes on Taxonomy
Discovered in 1969 and formerly recognized as a full species, Batrachoseps aridus.
Based on a recommendation by Wake and Jockusch, B.aridus was synonymized with Batrachoseps major in 2002.
In 2000, using DNA studies, Jockusch and Wake * reduced Batrachoseps aridus to a subspecies of Batrachoseps major - B. m. aridus, making the rest of B. major, the subspecies B. major major.
Some texts do not use this taxonomy because B. aridus is a federally-protected endangered species.
Robert W. Hansen and David B. Wake in Lanoo, 2005, retain the use of B. aridus Brame, 1970 - Desert Slender Salamander
The habitat of this salamander is very fragile. The Hidden Palm Canyon site is a State Ecological Preserve that can only be entered with a permit. This salamander is currently protected by California law.
A U.S. Fish and Wildlife Service study published June 17, 2009 reports that no salamanders have been found during CDFG searches since 1996, but these searches have only been casual cursory searches of surface cover, because a more thorough search would damage the fragile habitat. Since the salamanders most likely remain deep in limestone crevices by day, emerging at night to feed, a night survey would be the best search method.
The study also mentions that the salamander habitat could have been damaged if the hydrology of the area was modified by highway construction that resulted in more damaging flows during storms. Climate change could also be causing increased evaporation leaving less moisture for salamander habitat. Introduced water-hungry Tamarisk trees may also be a threat to the Guadalupe Canyon population.
Brame, A. H., Jr. "A new species of Batrachoseps (slender salamander) from the desert of southern California." Contributions in Science. Los Angeles County Museum, 200. 1970
Thelander, C. G., ed., 1994. Life on the Edge: A Guide to California's Endangered Natural Resources Volume I: Wildlife. Biosystems Books, Santa Cruz, California.
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 Amphibians of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2009.
Bishop, Sherman C. Handbook of Salamanders. Cornell University Press, 1943.
Lannoo, Michael (Editor). Amphibian Declines: The Conservation Status of United States Species. University of California Press, June 2005.
Petranka, James W. Salamanders of the United States and Canada. Smithsonian Institution, 1998.
* Jockusch, Elizabeth and David Wake. Detecting Species Borders Using Diverse Data Sets. Pp. 95-119. In Bruce, Jaeger and Houck (editors). The Biology of Plethodontid Salamanders. Kluwer Academic/Plenum Publishers, New York, 2000.
The following conservation status listings for this animal are taken from the October 2021 California "Special Animals List" and the October 2021 "State and Federally Listed Endangered and Threatened Animals of California" list, both of which are produced by multiple agencies and available here: https://www.wildlife.ca.gov/Data/CNDDB/Plants-and-Animals. You can check the link to see if there are more recent lists.
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 go to the NatureServe and IUCN websites to check their rankings.
NatureServe Global Ranking
Species Apparently Secure.
Subspecies Critically Imperiled