California Reptiles & Amphibians

Batrachoseps gregarius - Gregarious Slender Salamander



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Range in California
: Red

Range Map of Southern Sierra
Nevada Slender Salamanders







 
Adult, Kern County
 
Adult, Madera County
Underside of adult, Madera County
Adult, Tulare County
   
 
These salamanders were found underneath ground debris along with some eggs. As their name indicates. this species often forms communial nests, but the females typically leave the site after laying. Male and subadult salamanders will often still be found under the same cover as the eggs. © 1998 Duncan Parks
 
Comparisons with some similar sympatric Slender Salamanders
Comparison of B. diabolicus and B. gregarius
Comparison of B. simatus and B. gregarius
Comparison of B. gregarius with B. relictus (bottom.) Note the larger, more robust body and limbs on B. relictus.
© 2004 Brad Alexander
 
Comparison of B. gregarius (top) sympatric B. kawia (bottom) Note the larger, more robust body and limbs on B. kawia
Comparison of B. kawia and B. gregarius

 
Habitat
Habitat, Kern County
Habitat, 1,200 ft. Mariposa County
Habitat, 3,800 ft. Kern County
   
 
Habitat, 4,700 ft. Mariposa County


 
Description
Size
Adults are 1 1/5 - 1 4/5 inches long (3 - 4.6 cm) from snout to vent.
Appearance
A small slim salamander with 17-19 costal grooves. Short limbs, a long slender body with a narrow head and a 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.) The ground color is dark blackish-brown with a lighter brownish dorsal stripe with tan highlights and dark flecks. Many small white spots mark the ground color. The venter is lighter, dark to pale gray.
Behavior and Natural History
Breathes through smooth moist thin skin instead of lungs.

Surface-active from the beginning of the fall rains until the end of the rainy period, which is typically from late Octorber or November to March or April. It is presumed that they go underground to avoid the extreme temperatures of winter and summer. Typically found under rocks, logs, bark, and other debris.

Typical of most Slender Salamanders, when disturbed, this salamander may coil up and remain still, relying on cryptic coloring to avoid detection. It might also uncoil quickly and spring away, repeatedly bouncing over the ground, or drop its tail to distract a predator. The tail is easily broken off, but it can be regenerated.

Feeding behavior is not known, but other Batrachoseps species are sit-and-wait predators that use a projectile tongue to catch prey.
Diet
Most likely eats a variety of small invertebrates.
Reproduction and Young
Reproduction is terrestrial.  Breeding and egg laying occurs with the beginning of fall rains, which varies from year to year and with elevation (typically November to early January at lower elevations, and late March to late April at higher elevation locations.)

Females lay eggs in communal nests in the spring (fall in southern populations) in moist places under rocks, logs, bark, or leaf litter. Females then abandon the nests. Nest sites have been found with from 10 - 300 eggs. Females at the northen end of the range lay more eggs - an average of 15.3 eggs, than those at the southern end of the range who average 7.3 eggs, according to a 1997 study by Jockusch and Mahoney. Young hatch fully formed.
Range
Endemic to California. Occurs along the west slope of the central and southern Sierra Nevada Mountains from the southern boundary of Yosemite National Park almost to the kern River.

Occurs in sympatry with B. kawia, and possibly with B. relictus, B. regius, B. attenuatus, and B. diabolicus.
Habitat
Mostly found in oak woodlands in the foothills, but they are also found in high-elevation coniferous forests, and grasslands on the floor of the Central Valley, including very hot and dry habitats at the southern end of its range.
From around 1000 - 5,900 ft. (300 - 1800 m.)
Taxonomic Notes
Prior to its description in 1998, B. gregarius was recognized as B. nigriventris. Lower elevation southern populations are more slender, live in much drier habitats, lay fewer eggs than those in the north, and lay eggs in the fall. Future studies may establish that these are two different forms.
Conservation Issues  (Conservation Status)
Listed as imperiled by one organization, though there are no apparent issues with this salamander other than some possible loss of habitat at the eastern edge of the Central Valley to development and agriculture.

Taxonomy
Family Plethodontidae Lungless Salamanders
Genus Batrachoseps Slender Salamanders
Species


gregarius Gregarious Slender Salamander
Original description
Jockusch, E. L., D. B. Wake, and K. P. Yanev. "New species of slender salamanders, Batrachoseps
(Amphibia: Plethodontidae), from the Sierra Nevada of California." Contributions in Science, Natural History
Museum of Los Angeles County, #472 1998.

Meaning of the Scientific Name
Batrachoseps: Greek - amphibian, frog lizard - describes lizard-like appearance.
gregarius: Latin - flock or herd, referring to the habit of laying eggs communally.

from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz

Alternate Names
Formerly recognized as Batrachoseps nigriventris - Black-bellied Slender Salamander.

Similar Neighboring Salamanders
B. diabolicus
B. regius
B. kawia
B. relictus

More Information and References
Natureserve Explorer

California Dept. of Fish and Game

AmphibiaWeb

Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003.

Behler, John L., & F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992.

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.


Conservation Status

The following status listings come from the Special Animals List which is published several times each year by the California Department of Fish and Game.


Organization
Status Listing
U.S. Endangered Species Act (ESA) None
California Endangered Species Act (CESA) None
California Department of Fish and Game None
Bureau of Land Management None
USDA Forest Service None
Natureserve Global Conservation Status Ranks G2G3 S2S3 Imperiled
World Conservation Union - IUCN Red List




IUCN:LC Least Concern
 


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