Eumeces
skiltonianus
(Western Skink)
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Key Characteristics |
Smooth, cycloid scales |
Elongate body |
Light colored lines on a brown ground color |
General
Description:
Western Skinks
are unique among Idaho lizards in that they are covered with smooth, cycloid
scales. These scales give Western Skinks a very glossy appearance. Western Skinks
have a somewhat long, slim body and a tail that may be a bright blue color.
The tail coloration fades to a gray
in adulthood, but usually retains some hint of blue. Western Skinks readily
autotomize
(lose) their tails, and the bright blue
coloration found on juveniles may add to the wriggling tail's distractability.
The rest of the body is also handsomely colored
with stripes of tan, cream and brown. There is a wide vertebral stripe (runs
down the middle of the back), which is usually a tan color, but on juveniles,
it is often a very dark brown. The vertebral stripe is bordered on either side
by dark (black or brown) stripes (these are not apparent on juveniles, as their
vertebral stripe is the same color). The next stripes are cream or light tan
in coloration and extend dorsolaterally (between the back and sides). These
light colored stripes are bordered on the sides by a fairly wide dark brown
stripe. Finally, there is one more lateral (side) stripe on each side that is
a light cream color, this blends into the light
ventral coloration. All of the stripes originate on the head and extend
onto the base of the tail (Stebbins 1985). Males may have an orange tinge on
their chin and sides of their head during breeding season (Nussbaum et al. 1983).
Western Skinks are small to medium-sized lizards that can attain snout-vent length sizes of 76 mm (3 in.) and 201 mm (7.9 in.) total length (Storm and Leonard 1995).
There is relatively
little known about the reproduction of Western Skink populations in the Northwest.
However, based on information of Western Skinks in Utah, they probably mate
in May or June, and deposit 2-6 eggs in July (Nussbaum et al. 1983). Based on
the observation of recently hatched neonates in August, we can assume that the
eggs hatch sometime during August and perhaps September. One note of interest
concerning the reproductive habits of Western Skinks is that the females display
parental care for the eggs. The female will stay with the eggs, protecting them
against predators, repairing the nest and possibly providing additional heat
by basking
and then returning to the nest (Behler and King 1979), (Nussbaum et al. 1983),
(Storm and Leonard 1995).
Habitat:
Western Skinks
are generally found in a variety of habitats including pinion-juniper forests,
grassy areas, desert
shrub, talus slopes and canyon rims (Storm and Leonard 1995). Stebbins
(1985) mentions that they are often found in areas associated with water (rocky,
brushy areas along streams). I have encountered Western Skinks at sites
that did have water nearby, but as Stebbins states (and based on my own experiences)
this isn't a requirement.
Idaho
Distribution:
Western Skinks
can be found across much of Idaho, with the exception of the southwestern
corner, and the southeastern edge of the state. Ranges from south-central
British Columbia to southern Baja California, and east to western Montana,
Idaho, eastern Utah, north-central Arizona, and southern Nevada. Also found
on some islands off coast of California and Baja California. Isolated populations
exist in California and Nevada.
Diet:
Feeds on variety of insects (crickets,
beetles, grasshoppers, flies, etc.), spiders, and earthworms.
Ecology:
Hibernates
/aestivates
.
Inactive in cold, winter weather; duration of inactive period varies with local
climate. Secretive; ecology and life history are not well known. In Idaho, night
snakes, striped whipsnakes, and raptors are predators.
Reproduction:
In Utah, mating occurs in May or June,
female lays 2-6 eggs in July, and eggs hatch in August. Female guards eggs
and stays with hatchlings until they disperse from nest.
Conservation:
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Status: |
Unprotected nongame species |
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Global Rank: |
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State Rank: |
S5 |