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5.7 Biological Resources

Disturbance and loss of large colony roost sites during the maternity and hibernation
seasons are considered primary factors that may negatively impact the Townsend’s big-
eared bat in California (CDFW 2014). There are no known maternity or significant roosting
sites for the Townsend’s big-eared bat on or in the vicinity of the Project site. The oak
woodlands in western portions of the Project site may provide temporary roost sites for
individual Townsend’s big-eared bats. Potential foraging habitat is expected to be limited to
edge habitats along streams and areas adjacent to and within the oak woodlands in western
portions of the Project site outside the Project’s impact footprint; therefore, Project
implementation is not expected to impact the Townsend’s big-eared bat and no mitigation is
required. The loss of individual Townsend’s big-eared bats, however, may be considered
significant under Section 15380 of the State CEQA Guidelines. Implementation of MM 7-9 for
pre-construction bat surveys, MM 7-3 for biological monitoring during construction, and
MM 7-4 for clear demarcation of disturbance limits are recommended to avoid taking of
solitary roosting individuals that may be present within the Project’s impact footprint.

The Project site provides potentially suitable foraging habitat for both the pallid and western
mastiff bats, but limited roosting opportunities for pallid bats and no roosting opportunities
for western mastiff bats. Project implementation would result in the loss of roughly 7,000
acres of potentially suitable foraging habitat for these 2 bat species. This loss is small relative
to the amount of foraging habitat available to these two species elsewhere in the region;
therefore, the loss of potential foraging habitat for the pallid bat and western mastiff bat is
considered to be adverse but less than significant and no mitigation is required. The loss of
individual pallid bats, however, may be considered significant under Section 15380 of the
State CEQA Guidelines. Implementation of MM 7-3 for biological monitoring during
construction, MM 7-4 for clear demarcation of disturbance limits, and MM 7-9 for pre-
construction bat surveys are recommended to avoid taking of roosting individuals that may
be present within the Project’s impact footprint.

The Tehachapi pocket mouse has been reported in the vicinity of the Project site at points
across the Tehachapi foothills within grassland and desert shrub. One individual of this
species was also detected on the Project site during focused surveys. It is expected to occur,
albeit in very low numbers, within arid annual grassland and desert shrub vegetation types
on the site. The only area where this species was detected is outside the Project’s disturbance
limits. However, there is reasonable opportunity for this species to occur in very low
numbers within impact areas of potentially suitable habitat. Based on current known
distribution, this species is likely to occupy much of the Tehachapi foothill south facing slope
stretching from the project site to the northeast for some distance. Although small mammal
trapping surveys in the region are fairly limited, CNDDB records from recent years (2000
and up) provide evidence of this projected distribution. The loss of potentially suitable
habitat for this species would be considered adverse, however, substantial adverse effects
on the regional population are not expected to occur due to the relative abundance of mostly
contiguous habitat across the southern slope of the Tehachapi Mountains. The loss of
potentially suitable habitat is therefore considered less than significant. The loss of
individuals, however, may be considered significant under Section 15380 of the State CEQA
Guidelines. Implementation of MM 7-3 for biological monitoring during construction is
recommended to relocate individuals from the Project’s impact footprint if detected.

R:\Projects\PAS\CEN\000306\Draft EIR\5.7 Bio_051117.docx 5.7-152 Centennial Project
Draft EIR