LSA ASSOCIATES, INC. FRESNO RIVERSIDE 20 EXECUTIVE PARK, SUITE 200 949.553.0666 TEL BERKELEY PALM SPRINGS ROCKLIN IRVINE, 92614 949.553.8076 FAX CARLSBAD PT. RICHMOND SAN LUIS OBISPO

August 30, 2016

Eric Borstein Santa Susana Estates, LLC 11766 Wilshire Boulevard, # 820 Los Angeles, CA 90025

Subject: Results of Daytime Habitat Assessment and Nighttime Bat Emergence Survey at 10811, 10821, 10877, and 10921 Old Santa Susana Pass Road, Community of Chatsworth, Los Angeles, California

Dear Mr. Borstein:

This letter documents the results of a daytime bat habitat assessment and nighttime bat emergence survey performed on August 9, 2016, by LSA Associates, Inc. (LSA) on four undeveloped parcels (hereinafter referred to as the “study area”) located at 10811, 10821, 10877, and 10921 Old Santa Susana Pass Road in the community of Chatsworth, Los Angeles, California (see Figure 1, attached). The four parcels are contiguous to each other and have a cumulative area of approximately 11.52 acres. The study area is located between Old Santa Susana Pass Road and Farralone Avenue, which is just west of Topanga Canyon Boulevard and approximately one-half mile south of State Route 118 (SR-18).

The daytime assessment was conducted to locate potential bat roosting sites in various structures, mature trees, and any other potential roosting areas present throughout the study area, while the nighttime emergence survey was performed immediately following the daytime assessment to allow for the detection of any that might emerge from potential roosting sites shortly after dusk and to identify any bats present with acoustic monitoring. Furthermore, this assessment and nighttime survey were performed during the recognized bat maternity season (April 1–August 31 in southern California) to determine whether any maternity colonies or maternity roost sites are present in the study area.

INTRODUCTION Day roosts serve to protect bats from predators and the elements during the day while resting and/or rearing their young; in human-made structures such as buildings and bridges, these roosts are usually in small cavities or crevices. Bat species that commonly utilize human-made structures for roosting in southern California1 include the Mexican free-tailed bat (Tadarida brasiliensis), big brown bat (Eptesicus fuscus), Yuma myotis (Myotis yumanensis), and pallid bat (Antrozous pallidus). Other bat species that occasionally use human-made structures for roosting include small-footed myotis (Myotis

1 Townsend’s big-eared bat (Corynorhinus townsendii), a state Candidate for listing as threatened or endangered, is also known to use buildings; however, this species has been omitted from this list because it is sensitive to disturbance and would not be expected to roost in urban or semi-urban environments such as that where the study area is located.

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PLANNING | ENVIRONMENTAL SCIENCES | DESIGN LSA ASSOCIATES, INC.

ciliolabrum), California myotis (Myotis californicus), and canyon bat (Parastrellus hesperus). Although bat roosts in structures can be relatively easy to identify, tree roosts are more cryptic and require close examination. Some species of bats (e.g., western yellow bat [Lasiurus xanthinus], western red bat [Lasiurus blossevillii], and hoary bat [Lasiurus cinereus]) day roost in the foliage of trees while other bat species (e.g., big brown bat) day roost in crevices or cavities found in mature trees and snags.

Some types of day roosts where bats are particularly vulnerable to disturbance include maternity colonies in which female bats congregate to give birth and raise young, and hibernacula, where bats congregate to enter a period of hibernation during the winter months. A night roost, on the other hand, refers to a natural or human-made structure or structural feature (e.g., crevices, cavities, corners, and recessed open spaces that are sheltered from the wind) in which bats roost during the evening between foraging bouts. Night roosts are typically situated in or near a foraging area and play an important role in the energetics and social interaction of bats. Since bats have separate roosting and foraging habitat requirements, it is expected that some bats may utilize one area for foraging and another for roosting. While more extensive and direct impacts to bats occur through roost removal, destruction, or disturbance, indirect impacts such as a decline of prey base due to loss or modification of foraging habitat can also be substantial. Therefore, when assessing an area with regard to proposed alterations to habitat, a landscape-level approach is required to adequately determine potential impacts to bats.

STUDY AREA The study area is surrounded by vacant lots, low-density single-family residential homes, and equestrian-use properties (Figure 2). The study area consists of small to moderate horse pastures with scattered trees. The pastures appear to have been recently mowed. The majority of trees in the study area are large and mature and often occur along property boundaries, fence lines, and around the houses. In addition, several old structures, many of which have not been actively used for years, are present in the study area. These include houses, garages, storage and equipment sheds, and horse stables. A concrete-lined flood control channel extends across a portion of the study area.

Much of the study area consists of ruderal nonnative grassland and ornamental landscape vegetation. The ruderal grassland is heavily disturbed, frequently littered with scattered trash or debris, and consists primarily of nonnative grasses. The trees occurring in the study area consist of an assortment of native species such as mature coast live oak (Quercus agrifolia var. agrifolia) and blue elderberry (Sambucus nigra ssp. caerulea), as well as nonnative species such as Peruvian pepper (Schinus molle), common olive (Olea europaea), and various ornamental palms.

METHODS On the afternoon and evening of August 9, 2016, LSA Senior Biologist and Bat Specialist Jill Carpenter and LSA Biologist Lonnie Rodriguez conducted a daytime bat habitat assessment and nighttime emergence survey at the proposed project site. The daytime component of the bat habitat assessment consisted of walking throughout the entire study area on foot to locate any potential bat roosting sites on or around the various uninhabited structures (e.g., storage sheds and vacant houses) as well as among the trees. Inhabited buildings were not examined during this assessment. Potential bat

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roosting sites were identified by examining the structures for any features such as crevices or recessed spaces that may be suitable for use as day- or night-roosting habitat, as well as for the presence of bats or bat sign (e.g., guano, urine staining, or vocalizations) that would indicate current or past use of an area by roosting bats. Trees and snags were also examined for any cavities or crevices that might be used for day roosting.

Although bat roosts in human-made structures can be relatively easy to identify, tree roosts are more cryptic and require close examination, particularly in the case of foliage-roosting bats. Due to the nature of this roosting behavior (i.e., bats tend to roost singly, beneath leaves, and may roost in a different location each night), roosting activity in trees is typically difficult to confirm during a daytime assessment. Therefore, to increase the likelihood of finding any roosting bats present within the study area, a nighttime emergence survey was performed immediately following the daytime assessment to permit detection of any bats that might emerge from the trees or structures at dusk.

The nighttime emergence and acoustic portion of the survey was initiated 30 minutes before sunset and continued until one full hour after sunset. The biologists remained on site during the entire emergence period, and watched the various uninhabited buildings where potential bat roosting habitat was observed as well as the skyline around the trees for emerging bats in order to obtain an estimate of the number of roosting bats present as well as to correlate the recorded acoustic data with visual observations. Acoustic detectors (specifically, a combination of Pettersson D240X and Wildlife Acoustics EchoMeter 3+ ultrasound detectors operating in time expansion mode) were deployed near clusters of trees at five locations throughout the survey area to detect any bat echolocation calls and activity that might indicate the presence of roosting bats. The locations where acoustic detectors were deployed are shown on Figure 2. The data collected from these acoustic detectors consist of full- spectrum sonograms of echolocation calls, the files of which were subsequently analyzed using SonoBat 2.9 acoustic analysis software. Species identifications were made by comparing call recordings with a library of “voucher” calls from known hand-released bats.

At the conclusion of the emergence period 1 hour after sunset, all of the structures that had been identified as potential night-roosting sites were briefly re-examined for the presence of night-roosting bats.

RESULTS Most of the storage sheds within the study area are constructed from wood and corrugated metal and lack any crevices or cavity features suitable for day roosting. In addition, many of the storage sheds lack walls on all four sides, rendering them relatively open to the elements and therefore less desirable for use as day- or night-roosting sites. The horse stables also lack crevice features, but due to their more enclosed nature could provide night-roosting habitat for bats. Bat guano, consistent in size and deposition pattern with one of the Myotis species, was observed in one of the storage sheds near the horse stables in the middle of the property. This storage shed is small and is enclosed on multiple sides, which increases the thermal capacity of the structure and increases its desirability as a roost site. Although the structural features above the observed guano are suitable for day and/or night roosting, since no bats were present within that structure during the daytime assessment it is likely used for night roosting and not as a day roost or maternity roost.

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Although no day-roosting or maternity-roosting habitat was observed in any of the other structures within the study area, including the vacant residences, it should be noted that the attic spaces of the two vacant white houses and the houses occupied by tenants at the time of the survey have not been inspected to determine the presence or absence of roosting bats. These attic spaces are the only sites identified within structures throughout the study area that could potentially support maternity roosting.

Mature native trees (e.g., coast live oaks) and nonnative trees (e.g., palm trees) that could provide roosting habitat for foliage-roosting bats such as western yellow bat and hoary bat are present throughout the site. Small crevices and cavities within the oaks or any tree snags throughout the study area could also provide roosting habitat for a variety of bat species. These trees as well as other trees and shrubs throughout the study area may also provide foraging habitat for bats.

A concrete-lined flood control channel bisects a portion of the study area. The periodic presence of water within this channel attracts and provides foraging habitat for bats, and the concrete bridge that spans the channel may provide roosting opportunities.

During the nighttime emergence survey, no bats were observed emerging from any of the trees or snags, and no tree-roosting bat species were observed or acoustically detected during the nighttime survey. In addition, no bats were observed emerging from any of the structures, including the concrete bridge. The first bats acoustically detected were canyon bats, which likely emerged from the rock outcrops and boulders in the adjacent hillsides. Other bats observed foraging in the study area (including along the flood control channel) during the nighttime survey included small-footed myotis, Mexican free-tailed bat, big brown bat, California myotis, and possibly Yuma myotis.1 No large concentrations of bats were observed, and none of the observed bats appeared to originate from anywhere within the study area itself.

No night-roosting bats were observed in any of the structures (e.g., storage sheds) examined for bats after the conclusion of the emergence period 1 hour after sunset.

CONCLUSIONS AND RECOMMENDATIONS No bats were observed emerging from or entering any of the various structures during the nighttime survey. The majority of bats observed and identified acoustically were canyon bats, which commonly roost in rock outcrops and boulders such as those found in the hillsides adjacent to the study area and only occasionally roost in human-made structures such as buildings. The other bat species observed and identified during the nighttime survey included small-footed myotis, Mexican free-tailed bat, big brown bat, California myotis, and possibly Yuma myotis. Although these species do roost in human- made structures, the observed bats did not seem to originate from the study area and likely emerged from roosts in buildings or natural roost features (e.g., rocks or mature trees) on adjacent parcels.

1 Both California myotis bats and Yuma myotis bats produce a similar call terminating at 50 kilohertz (kHz). Conclusive determination of some of the call sequences could not be made due to characteristics in the call structures that overlap both species; however, at least a few of the several 50 kHz sequences recorded during the August 9, 2016, survey were diagnostic for California myotis.

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None of the bats observed during the survey are special-status species. Database records from the 1950s revealed the occurrence of two special-status bat species (i.e., California leaf-nosed bat [Macrotus californicus] and western mastiff bat [ perotis californicus]) in reasonably close proximity to the study area; however, no suitable roosting habitat for California leaf-nosed bats is present within the study area. In addition, the California leaf-nosed bat is now considered extirpated from that portion of its range. The western mastiff bat was also not detected during the nighttime survey and is not expected to roost in the study area; however, it is possible that this species may occasionally forage above the study area. Although no special-status bat species were observed in the study area or immediately adjacent areas during the focused survey for bats, there is moderate potential for western yellow bat, a California Department of Fish and Wildlife (CDFW) species of special concern that roosts in palm trees, to occur in the study area.

Although the mature oak trees and ornamental trees such as palms present within the survey area are suitable for roosting by foliage-roosting species such as hoary bats and western yellow bats, no bats were observed emerging from the trees, and no tree-roosting bat species were acoustically detected during the nighttime emergence survey. Based on these survey results, there is no evidence that bats are currently utilizing any of the trees within the study area for day roosting; however, it should be noted that since bats are highly mobile species, it is possible that although they are currently absent from the study area, foliage-roosting bats may roost within suitable trees at any time.

Therefore, to avoid potential direct mortality to flightless young bats, LSA recommends that tree trimming/removal activities associated with the proposed project be conducted outside the recognized bat maternity season, which occurs from April 1 through August 31 in southern California. This period also coincides with the bird nesting season of February 15 through September 1. If trees must be trimmed or removed during the bat maternity season referred to above, LSA recommends conducting a bat survey of those trees within 2 to 3 days prior to the trimming or removal. If any bat roosting is detected, no tree removal or trimming activities will occur within 100 feet of the roosting location until the bats have completed their roosting activities.

Bat guano consistent in size and deposition pattern with one of the Myotis species was observed in one of the storage sheds near the middle of the property. Although the structural features above the observed guano are suitable for day and/or night roosting, since no bats were present within that structure during the daytime assessment, it is more likely used for night roosting and not as a day roost or maternity roost. Based on the results of the daytime assessment and nighttime survey, in which no bats appeared to emerge from any of the structures and large concentrations of bats were not observed, there is no evidence that bats are currently utilizing any of the structures within the study area for day roosting or for maternity roosting. It should be noted, however, that the attic spaces of the two vacant white houses and the houses occupied by tenants at the time of the survey have not been inspected to determine the presence or absence of roosting bats, so this possibility cannot be entirely ruled out. Potential entry points were observed in the gable vents of the two vacant white houses. In addition, since bats are highly mobile species, it is possible that bats may roost within any suitable roost feature at any time.

Therefore, to avoid potential direct mortality to roosting bats, LSA recommends that the attic spaces of the various houses be examined for the presence of bats within 2 to 3 days prior to demolition of those structures. These attic spaces are the only sites identified within structures throughout the study area that could potentially support maternity roosting by large numbers of bats. If maternity-roosting bats

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are found, LSA recommends that a humane eviction and exclusion be performed outside of the recognized bat maternity season (April 1–August 31 in southern California) to prevent potential direct impacts to roosting bats, including flightless young, and that alternate roosting structures (e.g., “bat houses”) be installed to mitigate for the loss of habitat. However, unless bats are found roosting within the attic spaces of the various residences, no extensive loss of bat day-roosting habitat is anticipated from the removal of structures within the study area.

If you have any questions regarding this report or would like to discuss the project further, please contact me at [email protected] or at (949) 553-0666.

Sincerely,

LSA ASSOCIATES, INC.

Jill Carpenter Senior Biologist Bat Specialist

Attachment: Figure 1: Project Location Figure 2: Bat Survey Study Area

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Ã14 Ã126 à ¨¦§5 Ventura Project County Location

Ã118 ¨¦§210 Ã23 ¨¦§405 Ã170 ¤£101 Ã134 Ã27 Los Angeles County Ã2

LEGEND FIGURE 1 Project Boundary

0 1000 2000 Chatsworth Property FEET Project Location SOURCE: Esri World Topographic Map (2016) I:\BRS1601\GIS\Project_Location.mxd (8/29/2016) Service Layer Credits: Image courtesy of USGS Image courtesy of LAR-IAC Earthstar Geographics SIO © 2016 Microsoft Corporation © 2010 NAVTEQ © AND

LEGEND FIGURE 2 Project Site Boundary S" Acoustic Detector Location

0 100 200 Chatsworth Property FEET Bat Survey Study Area SOURCE: Bing Maps (2014); LSA (8/2016) I:\BRS1601\GIS\BatSurveyStudyArea.mxd (8/29/2016)