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NOTES ON THE HERPETOFAUNA
OF COASTAL MONTEREY COUNTY, CALIFORNIA. Robert
George Sprackland, Ph.D.
Abstract
Monterey County has been undergoing rapid development and human growth
since 1987. The available habitat for many local reptiles and amphibians has
been reduced. Nevertheless, most species appear as abundant today as they were
in the late 1980s.
Monterey
County is a heavily populated region southwest of California's Silicon Valley,
with much of the human growth in the area a direct result of the booming
electronics industry. Though the region has been sampled for herpetofauna during
much of the twentieth century, there have been few comprehensive reports on the
herpetofauna for any single time period. Thus, we know about short-term studies
conducted on particular species, or have distribution records that have
subsequently become reduced as human development of the area increased (e.g.
Smith, 1946)
This study recounts data for specimens observed or collected over the
period 1987-1999 by the author and various assistants. Study sites were chosen
during 1987-88, and visited annually or more as possible during the ensuing
years. Materials
and methods.
Reptiles were observed in
situ and
collected as required to confirm identity of species. Specimens were generally
released on site, but some specimens were kept for additional lab studies. All
collected animals were taken under appropriate California permits issued by the
Department of Game and Fish. Observations were made in all months, but most taxa
were seen between February and April; the fewest site visits took place in
August, November, and December.
Study sites were chosen and visited at irregular intervals. Sites
include: ·
Zmudowski
State Beach, north of Elkhorn Slough;
Figure
1. Map of Monterey Bay with study localities marked. Faunal
content. 1.
Amphibia.
Ensatina eschscholtzii eschscholtzii, ensatina. The typical taxon is a predominantly
unpatterned member of the best-studied ring species in herpetology. Two
specimens were observed, in 1998 and 1999. Both came from the same area, in the
hills above highway 1, east of the 17-mile drive. They were taken under almost
dry bark on the ground. Nearby plants were primarily pines, and the soil was a
sandy loam. The subadult found in June 1998 was orange-brown with a pale orange
venter. An adult male photographed in April 1999 was more brick-orange dorsally
with a pinkish venter. The eyes were black.
Batrachoseps
pacificus, Pacific slender salamander. A common species found in a
variety of habitats from sand dunes (under wooden debris) to mountainside pine
fields. In all cases, pine trees and short dune grasses were nearby. Two
specimens were taken from under plywood debris on sand at Asilomar Dunes. Three
other salamanders were taken from beneath moist bark litter on mulchy soil.
Additional specimens were taken within a 2 km. Radius of Asilomar Conference
Center, on and near Center grounds, but never at elevations above 25 meters.
Their choice of habitat suggests that they are more salt tolerant than many
other amphibians. They are strictly seasonal, found only in the winter months
(late October-early April, depending on rainfall).
Aneides
lugubris, arboreal salamander. This salamander is ecologically sympatric with Batrachoseps
pacificus, and almost as
common in the same habitats and localities. One specimen was taken from under a
board at the base of a sand dune at Asilomar Conference Center, within 12 feet
of a Batrachoseps pacificus
and in virtually identical conditions. Three specimens were observed in April,
shortly after the rains halted, and one was taken from deep within a fallen tree
in mid June. The interior wood was largely rotten and powdery. The salamander
shared this refugium with several centipedes and pillbugs.
Pseudacris
regilla,
Pacific treefrog. Monterey County’s most ubiquitous amphibian is found in
almost every freshwater habitat, especially in roadside ditches. The frogs are
more likely to be heard than seen, as the males call during most of the year,
from February until October. However, they rarely call at temperatures below 55°
F, and typically start the season during the first warm rains. They have been
heard calling on bright days as early as 1400 hrs, but more generally start
about an hour after sunset. 2.
Reptilia.
Anniella
pulchra pulchra, silvery legless lizard. This species, which has been
recorded as far north as San Francisco, is now unknown along the coast north of
Zmudowski State Beach. In fact, only two specimens were observed at the Beach
(1989) and none seen since, despite hundreds of man hours searching. I have
visited more northerly historic sites, and in all cases find the dunes largely
covered by Mediterranean ice plant. In study sites where ice plant has been
introduced, Anniella
becomes less easy to encounter. It is suggestive, though by no means conclusive,
that ice plant proliferation has an adverse effect on the microenvironmental
needs of legless lizards.
Anniella
pulchra nigra, black legless lizard. This taxon is generally considered a
subspecies, but several workers are now examining the validity of that
assumption. Both Federal and California regulations list black legless lizards
as Endangered, and there has been little monitoring of these lizards in the past
two decades. Confounding survey results is the fact that subadults of A.
p. nigra may be
identical in coloration to A.
p. pulchra.
Considerable information about distribution and microhabitat utilization of
black legless lizards has been accumulated by Patti Kreiberg during her
long-term collection and reintroduction work for the state of California. The
lizards are found from about 8 km south of Elkhorn Slough southward to the
Carmel River, and inland as far as 12 km. Though found near the surface in
loose, loamy or sandy soils, typically under mock lupine and other low, broad
plants, they are absent from habitats that are home to local scorpions. Elgaria multicarinata, southern alligator lizard. Rarely encountered, but two adults and two subadults were sighted (one photographed), and five shed skins were encountered during the surveys. Observed lizards were seen very near the ocean, taking refuge in holes excavated by local ground squirrels. One was seen near the north entrance to17-mile Drive.
Sceloporus occidentalis occidentalis, western fence lizard. Easily the most plentiful
reptile in the county, found in almost all suitable habitats from coastal sand
dunes into mountain clearings and hillsides. Females are generally more colorful
dorsally, displaying tiny flecks of turquoise on each scale. Males and young are
slatey gray. Sceloporus is
an adept sand swimmer, and many specimens were taken after watching a small
"gopher track" progress in the sand between mock lupine bushes.
Thamnophis sirtalis
fitchi,
garter snake. Widely distributed, but rarely encountered, this species is found
in every habitat that was surveyed, with the exception of on the beach itself.
The predominant color pattern seen in Monterey County is dark black, lacking
lateral markings, and with a distinct yellow vertebral line. The snakes are
active at temperatures as low as 55° F and as high as 90° F, though they are
rarely seen basking in direct sunlight for long. Acknowledgements.
I am grateful for the help of my wife, Teri, during innumerable hours in
the field, at libraries, and in editing sessions. Other people who contributed
to fieldwork are Richard Bartlett, Geoffrey N. Swinney, Andy and Jane Rowell,
and Patrick and Christopher Gardner. Tom Moss arranged a study permit for work
at Asilomar Conference Center. Special thanks to Patti Kreiberg for sharing her
extensive knowledge of the ecology of black legless lizards, collected under
State permits for a reintroduction project. Rossman,
Douglas, Neil Ford and Richard Seigel. 1996. The garter snakes: evolution and ecology.
University of Oklahoma Press. Smith,
Hobart. 1946. Handbook
of the lizards of the United States and of Canada. Comstock
Publishing.
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