Ensatina
Ensatina eschscholtzii
![[Ensatina]](/images/121ds.jpg)
Description
Physical
A small stocky salamander with a relatively large head, adults reach a size of approximately 7.5cm (3 inches) snout to vent. Typically has 12 to 13 costal grooves, and a distinctive tail constriction at the base of tail that readily distinguishes this species from any other species. Young can be quite small, the costal grooves and tail constriction may not be readily visible.
Ensatinas have four toes on the front feet, five on the rear.
Ensatinas are member of the Plethodonidae family, which is a chiefly New World family of salamanders that lacks lungs. They breathe through their skin. Extreme care should be taken when observing these salamanders to avoid chemical contamination of their skin. If at all possible, do not use lotions or bug spray and wear latex gloves, and keep any handling to a minimum.
Color and Pattern
A highly variable species. All specimens have yellow, greenish yellow, or orange on all four limbs from the base of the limb to the elbow, color seems to be more vibrant in young. Brown to nearly black above, often with light speckling. Small orange blotches may be visible on adults, especially in the south eastern part of the county where they are more heavily influenced by the Sierra Nevada Ensatina.
Sexual Dimorphism
Males have longer more slender tails than females.
Habitat
Like all western lungless salamanders, Ensatinas are a terrestrial species that avoids submersion in water.
Primarily a forest salamander, Ensatinas like well forested areas with rotting bark and leaf litter they can use for cover, often found near streams. They avoid warm and dry conditions, taking refuge underground or in rotting stumps when the climate is too hot or dry.
Ensatinas are easiest to locate in the spring or fall when it has recently rained.
Diet
Ensatinas feed on invertebrates such as sowbugs, spiders, and a variety of insects.
Distribution Range
General range map taken from CWHR, modified.
Museum records taken from following institutions: CAS Herps, MVZ Herps.
Throughout most of Shasta County except the drier eastern part, absent from the lower Sacramento River Valley.
Typical Elevation
Based on records in our database, in Shasta County the Ensatina is typically found at elevations from 330m to 1492m (1081ft to 4893ft).
Reproduction and Young
Typically breeds in the spring, may breed in the early summer and/or fall in some areas. Lays eggs in clusters of 8 to 16 eggs typically in rotting logs or burrows, females are maternal and guard the eggs until they hatch, which can take up to six months.
Like other lungless salamanders, no larval stage takes place outside the eggs. The eggs hatch into smaller versions of adults.
Additional Information
Notes
The CWHR range map data for this species has been modified. The CWHR range included the valley floor, which is incorrect. To get the range showed, first I subtracted the range of the California Red-legged Frog (Rana draytonii) as it is lower elevation species. Then I manually modified the result to encompass all museum records that fell outside the result. This solution is not as good as proper niche modeling would likely produce, but it is a lot better than the original range.
Almost all Ensatina in Shasta County are considered to be intergrades between multiple subspecies. Our Ensatinas are part of a large “bridge” population that has contact and gene flow with Ensatinas from Oregon, the Coast Range Mountains, and the Sierra Nevada Mountains.
Intergrade does not mean the convergence of multiple formerly isolated subspecies coming together, though it sometimes does happen that way. Usually however it means that specimens in the integrade zone express intermediary characteristics from the described distinct subspecies that contact the intergrade zone.
Virtually all of our Shasta County Ensatinas exhibit traits identified with the Oregon Ensatina (Ensatina eschscholtzii oregonensis) and the Sierra Nevada Ensatina (Ensatina eschscholtzii platensis). In extreme south eastern part of the county, some appear to be “pure” Sierra Nevada Ensatina.
Ring Species
The Ensatina is an excellent example of a ring species, demonstrating evolutionary speciation without isolation in action.
Generally, if two groups of similar animals come in contact yet are reproductively isolated, they are considered to be distinct species. For example, the Western Fence Lizard (Sceloporus occidentalis) and the Common Sagebrush Lizard (Sceloporus graciosus) are quite similar and frrquently share habitat here in Shasta County at higher elevations. However, they do not hybridize or share gene flow with each other, they are reproductively isolated and therefore fit the Biological Species Concept definition of distinct species.
As the Ensatina species moved down from Oregon into California, the species did not find the great valley to their liking, so the range of the species forked as it moved south, down the Coast Range Mountains and down the Sierra Nevada Mountains. When the species finally reached the southern side of the great valley, the populations converged again. However, when they converged again, Ensatinas on the Coast Range side of the valley had evolved differently enough from Ensatinas on the Sierra side of the valley that they very rarely hybridize in the contact zone.
In this contact zone, the Monterey Ensatina (Ensatina eschscholtzii eschscholtzii) shares habitat with but is reproductively isolated from the Yellow-blotched Ensatina (Ensatina eschscholtzii croceater).
However, the Monterey Ensatina is not reproductively isolated from the Yellow-eyed Ensatina where they come into contact as they move towards San Francisco Bay Area, which is not reproductively isolated from the Ensatina as the range moves north of the San Francisco Bay Area and around the north side of the valley, which is not reproductively isolated from the Sierra Nevada Ensatina as the Ensatina goes down the Sierras, which is not reproductively isolated from the Yellow-blotched Ensatina back down at the bottom of the great valley.
Were it not for the continued presence of the Ensatina between the Coast Range and Sierra population to the north of the valley, the Coast Range and Sierra populations likely would be classified as distinct species. However, since Ensatinas of both sides of the valley are not reproductively isolated from the Oregon Ensatina, they are all classified as a single species. Since our Ensatinas are part of the population that glues the Coast Range and Sierra Ensatinas together, they are in my mind kind of special.
Images
Unless otherwise noted, all images are of wild specimens in Shasta County.
Please be kind, do not hotlink images and do not use images without permission of the copyright owner.
![[Ensatina]](/images/12sm.jpg)
![[Ensatina]](/images/95sm.jpg)
©Michael A. Peters
Very young, quite probably bred earlier this year. Boulder Creek Drainage, Whiskeytown National Recreation Area.
![[Ensatina]](/images/121sm.jpg)
©Michael A. Peters
Adult. Notice the constriction at the base of tail that readily identifies this species. Tamarack Road, Shasta County, CA.
Habitat Shots
Unless otherwise noted, these habitat shots are from within Shasta County where this species is known to occur.
![[Ensatina habitat]](/images/13sm.jpg)
![[Ensatina habitat]](/images/122sm.jpg)
©Michael A. Peters
An adult Ensatina was found under one of the rocks in the foreground. Tamarack Rd, Shasta County, CA.
Similar Species
Adult Ensatinas can be readily distinguished from other Shasta County salamanders by the distinctive constriction at the base of their tail. Young Ensatinas however may not yet express that distinctive trait. The characteristics below deal with young Ensatinas.
Shasta Black Salamander and Black Salamander
Young Shasta Black Salamanders (Aneides iëcanus) and Black Salamanders (Aneides flavipunctatus) tend to have a greenish tint, a more triangular head, and a much longer tail in proportion to the body. While yellow may be present at the base of the limbs, if present it generally consists of small dots and is nowhere as extensive as in the Ensatina where it generally extends almost to the joint with lower limb.
Shasta Salamander
Young Shasta Salamanders (Hydromantes shastae) do not have the distinctive yellow or green on upper part of limbs and frequently have yellow on the tail.
Long-toed Salamander
Long-toed Salamanders (Ambystoma macrodactylum) have a distinctive bright yellow irregular dorsal stripe and yellow spots on the head.
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