COMMISSION

Bat Monitoring Program
In 2014, a monitoring program for bats was initiated and bat surveys conducted by a bat
biologist consultant occurred in July and August 2014.
Due to the variety of habitat types, the expansive study site, and
the potential for numerous species’ microhabitat requirements
that could be investigated, visual encounter surveys and passive
acoustic surveys are conducted at a few selected locations in
both the SVRA riding area and the Tesla-Alameda property.
Site visits were conducted on July 17, 24, 31, and August 11,
2014. Visual encounter surveys were conducted by examining
the external features of and entering the cavities of mines, large
rock cracks (e.g., small caves), and natural caves. Evidence of
guano, food debris piles, urine stains, roosting bats, carcasses
of dead bats, and any detectable audio signatures were noted
during each visit. Passive acoustic surveys began July 24 and
ended August 11, 2014. These surveys were conducted for
one or two week periods at Hidden Pond, Mitchell Ravine Pond, Tyson’s Basin, one cattle
trough located at a park residence, Lime Kiln Cave, and one large mine adit.
Passive acoustic devices consisted of the Wildlife Acoustics SM2 Bat meter. Units were
placed adjacent to the site of focus with a cabled microphone mounted on a PVC pole and
placed within the stock pond targeted for data collection. Alternatively, units were placed
within the opening of caves/mines such that the microphone head was mounted from the
roof of the structure. Units were set to collect data beginning at one hour before sunset
for five hours, and then for 30 minutes each hour until one hour after sunrise. Data were
analyzed using Kaleidoscope 2.0.7 software (Wildlife Acoustics). Acoustic signatures
that were not identifiable were ambiguous, or which overlapped significantly with another
species were discarded (de Silva and Meisel 2015, 49).
Clay Pit SVRA
Clay Pit SVRA is located two miles west of Oroville in Butte County. The Oroville Municipal
Airport, ranch lands, and a CDFW shooting range and wildlife area surround the SVRA’s
220 acres. The bowl-shaped topography has largely been created by past excavation of
clay minerals used in the construction of the Oroville Dam. The area was also mined for
gold, and dredge tailings remain, primarily in the southeastern corner of the park. A shallow
canal partially bisects the northern one-third of the park. The northern, upstream end of
the canal is fed by a very small, seasonal drainage that originates outside the park to the
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California State Parks, Off-Highway Motor Vehicle Recreation Commission