|Taxonomic Notes: This species was divided into three species by Bingham et al. 2018 Bulletin of the Museum of Comparative Zoology 161:403-427 (https://mczbase.mcz.harvard.edu/specimen_images/publications/Bulletin_161_10.pdf). See accounts of Hydromantes samweli and Hydromantes wintu.|
© 2018 William Flaxington (1 of 60)
Hydromantes shastae Gorman and Camp, 1953
David B. Wake1
1. Historical versus Current Distribution. Shasta salamanders (Hydromantes shastae) were discovered prior to 1915 but not described formally until their rediscovery in 1950 (Gorman and Camp, 1953), north of the current Shasta Reservoir in northern California. Subsequently, they have been found in a number of sites in the vicinity of the Reservoir, east and west of the Sacramento River, and both north and south of the Pit River arm of the Reservoir. However, the total range of the species is < 35 km in greatest dimension. The species ranges between about 300 and 900 m in elevation.
2. Historical versus Current Abundance. There is no indication that either the size of the range or the density of this species have undergone any substantive changes, although construction of Shasta Dam, road building, and mining all have impacted the species in the past. Development, mining, and other human activities continue to threaten the species, but most of the range of the species is on national forest lands that have little timber value.
3. Life History Features.
A. Breeding. Reproduction is terrestrial.
i. Breeding migrations. Unknown and unlikely.
ii. Breeding habitat. Caves have been the only sites where eggs have been found (Gorman, 1956); it is not known whether salamanders breed in other areas.
i. Egg deposition sites. Egg deposition has not been observed. The only eggs discovered were deposited in a cave (Gorman, 1956).
ii. Clutch size. Gorman (1956) studied two clutches of nine eggs each.
C. Direct Development. Gorman (1956) described late stages of development. Hatching of these clutches would have occurred in late October to early November had the eggs been left where found.
D. Juvenile Habitat. Unlikely to differ from adult habitat use. Juveniles and adults are found together on the surface during the winter.
E. Adult Habitat. Although the species was originally described from a cave and considered to be a cave species, individuals are commonly encountered on the surface from late autumn to early spring. Most populations occur in areas where limestone outcrops occur, and individuals are active on moist rock faces by night. Salamanders are found under rocks and logs and in leaf litter in lightly to densely forested areas, as well as in small to large caves. The forest is dominated by oaks (Quercus kelloggii) and pines (Pinus sp.).
F. Home Range Size. Unknown.
G. Territories. Unknown.
H. Aestivation/Avoiding Dessication. As summer progresses into higher elevations, surface activity is curtailed as the animals move into below-ground microhabitats. Whether they aestivate or simply move away from the surface is unclear. They have been found on the walls of caves during the summer. In August 1978, over 20 individuals were observed in a single small cave.
J. Torpor (Hibernation). Unknown and unlikely, because the winter is mild and they are active throughout.
K. Interspecific Associations/Exclusions. A common associate are Oregon salamanders (Ensatina eschscholtzii oregonensis). Less commonly encountered but with broadly overlapping distributions are black salamanders (Aneides flavipunctatus), rough-skinned newts (Taricha torosa sierrae), and Pacific giant salamanders (Dicamptodon tenebrosus).
L. Age/Size at Reproductive Maturity. Unknown.
M. Longevity. Unknown, but longer than 3 yr and possibly much longer.
N. Feeding Behavior. Members of this genus have highly specialized tongue projection capability, and can project the tongue both far and fast (e.g., Deban et al., 1997).
O. Predators. Unknown.
P. Anti-Predator Mechanisms. Adults respond to being handled or being touched with a sharp object by raising and undulating the tail (Brodie, 1977).
Q. Diseases. Unknown.
R. Parasites. Unknown.
S. Comments. This species shows great genetic substructuring, especially unusual given its small geographic range (Wake et al., 1978). The genetic data were analyzed by Larson et al. (1984), who found that the species conforms to a genetic structure and pattern of gene flow in accordance with an island model and a value of Nm (Slatkin, 1981) of 0.125, which means that effectively no species-wide gene flow is taking place now or in the recent past. Their distribution has been carefully mapped (Papenfuss and Brouha, 1979). General species accounts have been provided by Stebbins (1951, 1985), Gorman (1964, 1988), and Petranka (1998).
The three species of Hydromantes in California are closely related (Wake et al., 1978; Jackman et al., 1997), and this species appears to be a close relative of Mt. Lyell salamanders (H. platycephalus), from which they differ in elevational zonation and habitat characteristics. This species shows strong geographic differentiation in both allozymes and albumin (Wake et al., 1978).
4. Conservation. Shasta salamanders are considered State Threatened by the California Department of Fish and Game (www.dfg.ca.gov); with this protection they may not be taken or possessed at any time. Much of the distribution of Shasta salamanders is on national forest land, and there is little reason to be concerned for their survival. However, a number of populations are small and isolated, and human activities could easily lead to their destruction by relatively small amounts of habitat disturbance.
1David B. Wake
2Theodore J. Papenfuss
Literature references for Amphibian Declines: The Conservation Status of United States Species, edited by Michael Lannoo, are here.
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Citation: AmphibiaWeb. 2018. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 20 Sep 2018.
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