Atherton City Council
September 18, 2024

MONK & ASSOCIATES
Environmental Consultants
1136 Saranap Ave., Suite Q  Walnut Creek  California  94595 (925) 947-4867

BIOLOGICAL CONSTRAINTS ANALYSIS REPORT

TOWN OF ATHERTON GENERAL PLAN

HOUSING ELEMENT UPDATE PROJECT

ATHERTON, CALIFORNIA
November 30, 2023
Prepared for
M-Group
51 E Campbell Avenue #1247
Campbell, California 95009
Attention: Mr. Adam Petersen
Email: [email protected]
Prepared by
Monk & Associates, Inc.
1136 Saranap Avenue, Suite Q
Walnut Creek, California 94595
Contact: Mr. Mark Jasper
[email protected]
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TABLE OF CONTENTS

1. INTRODUCTION ............................................................................................................................1

2. SUBJECT PARCEL LOCATIONS AND SETTING.....................................................................1

3. ANALYSIS METHODS ..................................................................................................................4

4. SPECIAL-STATUS SPECIES.........................................................................................................4

4.1 Definitions................................................................................................................................4

5. CNDDB SEARCH AND DESKTOP REVIEW RESULTS...........................................................6

5.1 Potential Special-Status Plants on the Subject Parcels...........................................................6

5.1.1 CONGDON’S TARPLANT...........................................................................................................7

5.1.2 CRYSTAL SPRINGS LESSINGIA .................................................................................................7

5.1.3 SMALL-FLOWERED MONOLOPIA..............................................................................................7

5.1.4 WHITE-RAYED PENTACHAETA................................................................................................8

5.1.5 FRAGRANT FRITILLARY ...........................................................................................................8

5.1.6 SAN FRANCISCO COLLINSIA.....................................................................................................9

5.1.7 WESTERN LEATHERWOOD .......................................................................................................9

5.2 Potential Special-Status Animals on the Project Site .............................................................9

5.2.1 WESTERN BURROWING OWL..................................................................................................10

5.2.2 WHITE-TAILED KITE ..............................................................................................................10

5.2.3 PALLID BAT ............................................................................................................................11

5.2.4 SAN FRANCISO DUSKY-FOOTED WOODRAT..........................................................................12

5.2.5 NESTING BIRDS ......................................................................................................................12

6. STATE AND FEDERAL REGULATIONS PERTINENT TO THE SUBJECT PARCELS .....13

6.1 Federal Migratory Bird Treaty Act .......................................................................................13

6.1.1 APPLICABILITY TO THE PROPOSED PROJECT........................................................................13

6.2 California Fish and Game Code § 3503, 3503.5, 3511, and 3513.......................................13

6.2.1 APPLICABILITY TO THE PROPOSED PROJECT ........................................................................13

6.3 The Clean Water Act.............................................................................................................14

6.3.1 SECTION 404 OF THE CLEAN WATER ACT ............................................................................14

6.3.2 SECTION 401 OF THE CLEAN WATER ACT ............................................................................14

6.3.3 APPLICABILITY TO THE PROPOSED PROJECT ........................................................................15

6.4 Town of Atherton Tree Ordinance........................................................................................15

6.4.1 HERITAGE TREES TO BE IMPACTED BY THE PROPOSED PROJECT ........................................19

7. RECOMMENDATIONS................................................................................................................19

8. LITERATURE CITED...................................................................................................................23 Biological Constraints Report
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FIGURES
(At Back of Report)
Figure 1. Town of Atherton General Plan Housing Element Update Project Regional Map Figure 2. Town of Atherton General Plan Housing Element Update Project Location Map Figure 3A and 3B. Aerial Photographs of the Subject Parcels, Town of Atherton General Plan Housing Element Update Project
Figure 4A. Known CNDDB Records for Special-Status Plant Species Within 5 Miles of Atherton’s Town Limits
Figure 4B. Known CNDDB Records for Special-Status Wildlife Species Within 5 Miles of Atherton’s Town Limits
TABLES
(At Back of Report)
Table 1. Special-Status Plant Species Known to Occur within 5 Miles of Atherton’s Town Limits Table 2. Special-Status Wildlife Species Known to Occur within 5 Miles of Atherton’s Town Limits
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1. INTRODUCTION
Monk & Associates, Inc. (M&A) has prepared this Biological Constraints Analysis Report discussing M&A’s search of the California Department of Fish and Wildlife’s (CDFW) California Natural Diversity Database (CNDDB) for records of special status species within 5 miles of Atherton’s town limits as well as other biological resources and their associated constraints to development on the 25 parcels (hereinafter collectively referred to as the “subject parcels”) proposed for residential development or redevelopment as part of the Town of Atherton General Plan Housing Element Update Project (“the project”) (Figures 1, 2, 3A, 3B).

Biological resources include common plant and animal species, and special-status plants and animals as designated by the U.S. Fish and Wildlife Service (USFWS), California Department of Fish and Wildlife (CDFW), National Marine Fisheries Service (NMFS), and other resource organizations including the California Native Plant Society. Biological resources also include waters of the United States (U.S.) and State, as regulated by the U.S. Army Corps of Engineers (Corps), California Regional Water Quality Control Board (RWQCB), and CDFW.

2. SUBJECT PARCEL LOCATIONS AND SETTING
The subject parcels are all within Atherton’s town limits (Figure 2). The Town of Atherton is an incorporated town in San Mateo County bounded by Redwood City on the north, Menlo Park on the east and south, and Woodside on the west. The Town has an area of approximately 3,600 acres or 5.6 square miles; 89% of which is residential, 5% parks and open space, and 6% public and private schools and municipal facilities. The Town has been primarily developed with lower density residential uses, with very few commercial or industrial uses.

For each of the 25 subject parcels proposed for future development, Table A below lists, for each subject parcel, the habitats visible on Google Earth aerial imagery, the potential for “heritage trees” to be present, and the biological constraints to proposed development. Tree inventories were only available for previous tree surveys conducted at MFO-8, V1, and V4. The other parcels were only reviewed using Google Earth aerial imagery for potential to have heritage trees onsite. Subject parcels with trees visible on aerial imagery may have heritage trees onsite, while parcels with no trees visible in aerial imagery are unlikely to have heritage trees.

Table A. Atherton Housing Element Update Subject Parcels Subject Parcel Habitats Housing
Element
Zoning Action
Heritage
Trees
Present?1
Biological
Constraints
23 Oakwood
Developed,
landscaped, ruderal
herbaceous
Municipal code
amended site
Likely
Nesting bird
and bat survey
MC Site 1
Developed Municipal code
amended site
Possible, but
unlikely
None
1 Based on review of Google Earth aerial imagery. Note that tree inventories were only available for MFO-8, V1 and V4.

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Subject Parcel Habitats Housing
Element
Zoning Action
Heritage
Trees
Present?
Biological
Constraints
MC Site 2
Developed Municipal code
amended site
Possible, but
unlikely
None
MC Site 3
Developed,
landscaped
Municipal code
amended site
Likely Nesting bird
and bat survey
MFO-1
Developed,
landscaped
Multi-family
housing site
Likely Nesting bird
and bat survey
MFO-2
Developed,
landscaped
Multi-family
housing site
Likely Nesting bird
and bat survey
MFO-3
Developed,
landscaped
Multi-family
housing site
Likely Nesting bird
and bat survey
MFO-4
Developed,
landscaped
Multi-family
housing site
Likely Nesting bird
and bat survey
MFO-5
Developed,
landscaped
Multi-family
housing site
Likely Nesting bird
and bat survey
MFO-6
Developed,
landscaped
Multi-family
housing site
Likely Nesting bird
and bat survey
MFO-7
Developed,
landscaped
Multi-family
housing site
Likely Nesting bird
and bat survey
MFO-8
Developed,
landscaped
Multi-family
housing site
13 Nesting bird
and bat survey
MFO-9
Developed Multi-family
housing site
Likely Nesting bird
and bat survey
MFO-10
Developed, annual
grassland
Multi-family
housing site
Likely Rare plant
survey, nesting
bird and bat
survey,
Burrowing Owl
survey
MS Site 1
Developed Municipal code
amended site
Likely Nesting bird
and bat survey
MS Site 2
Developed Municipal code
amended site
Likely Nesting bird
and bat survey
Sacred Heart
School
Developed,
landscaped
Municipal code
amended site
Likely Nesting bird
and bat survey
V1
Landscaped
(planted trees),
annual herbaceous
Vacant site –
no zoning code
change
26 Rare plant
survey, nesting
bird and bat
survey
V2
Developed,
landscaped
Vacant site –
no zoning code
change
Likely Nesting bird
and bat survey
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Subject Parcel Habitats Housing
Element
Zoning Action
Heritage
Trees
Present?
Biological
Constraints
V3
Developed,
landscaped, ruderal
herbaceous,
oak/hardwood
woodland
Vacant site –
no zoning code
change
Likely Nesting bird
and bat survey,
rare plant
survey
V4
ruderal herbaceous,
oak/hardwood
woodland
Vacant site –
no zoning code
change
At least 4 Nesting bird
and bat survey,
rare plant
survey,
woodrat
midden surveys
V5
ruderal herbaceous,
oak/hardwood
woodland
Vacant site –
no zoning code
change
Likely Nesting bird
and bat survey,
rare plant
survey,
woodrat
midden surveys
V6 ruderal herbaceous,
oak/hardwood
woodland
Vacant site –
no zoning code
change
Likely Nesting bird
and bat survey,
rare plant
survey,
woodrat
midden surveys
V7 Developed, ruderal
herbaceous,
fragmented mixed
oak/hardwood
forest
Vacant site –
no zoning code
change
Likely Nesting bird
and bat survey,
rare plant
survey
V8 Developed, ruderal
herbaceous,
cropland
Vacant site –
no zoning code
change
Likely Nesting bird
and bat survey,
rare plant
survey
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3. ANALYSIS METHODS
Prior to preparing this Biological Constraints Report, M&A researched the most recent version of California Department of Fish and Wildlife’s (CDFW) Natural Diversity Database (CNDDB) (RareFind 6 application) for records of special-status plants and wildlife within five miles of Atherton’s town limits (CNDDB 2021). The CNDDB is a database maintained by the CDFW that provides historic and recent records of special-status plant and animal species known from the state of California. M&A also searched the 2021 electronic version of the California Native Plant Society’s (CNPS) Inventory of Rare and Endangered Plants of California (CNPS 2001) for records of special-status plants known in the vicinity of the subject parcels.

M&A reviewed all individual parcels subject to the Housing Element Update within the planning area on Google Earth and ESRI ArcMap to determine, visually, if there are or could be suitable habitats on any of the subject parcels that need further investigation (on the ground) and/or have constraints to development. All special-status species records were compiled in tables (Tables 1, 2). M&A examined all known record locations for special-status species to determine if specialstatus species could occur on any of the subject parcels or within an area of affect. The results of our literature research and desktop review are provided in the sections below.

4. SPECIAL-STATUS SPECIES

4.1 Definitions
For purposes of this analysis, special-status species are plants and animals that are legally protected under the California and Federal Endangered Species Acts (CESA and FESA, respectively) or other regulations, and species that are considered rare by the scientific community (for example, the CNPS). Special-status species are defined as:
• plants and animals that are listed or proposed for listing as threatened or endangered under the CESA (Fish and Game Code §2050 et seq.; 14 CCR §670.1 et seq.) or the FESA (50 CFR 17.12 for plants; 50 CFR 17.11 for animals; various notices in the Federal Register [FR] for proposed species);
• plants and animals that are candidates for possible future listing as threatened or endangered under the FESA (50 CFR 17; FR Vol. 64, No. 205, pages 57533-57547, October 25, 1999); and under the CESA (California Fish and Game Code §2068); • plants and animals that meet the definition of endangered, rare, or threatened under the CEQA (14 CCR §15380) that may include species not found on either CESA or FESA lists;
• plants occurring on Ranks 1A, 1B, 2A, 2B, 3, and 4 of the CNPS’ electronic Inventory (CNPS 2001). The CDFW recognizes that Ranks 1A, 1B, 2A and 2B of the CNPS inventory contain plants that, in the majority of cases, would qualify for State listing, and the CDFW requests their inclusion in EIRs. Plants occurring on CNPS Ranks 3 and 4 are "plants about which more information is necessary," and "plants of limited distribution," respectively (CNPS 2001). Such plants may be included as special-status species on a Biological Constraints Report
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case by case basis due to local significance or recent biological information (more on CNPS Rank species below);
• migratory nongame birds of management concern listed by the USFWS (Migratory Nongame Birds of Management Concern in the United States: The list 1995; Office of Migratory Bird Management; Washington D.C.; Sept. 1995); • animals that are designated as "species of special concern" by the CDFW (2023); • animal species that are “fully protected” in California (Fish and Game Codes 3511, 4700, 5050, and 5515).
• bat species that are designated on the Western Bat Working Group’s (WBWG) Regional Bat Species Priority Matrix as: “RED OR HIGH.” This priority is justified by the WBWG as follows: “Based on available information on distribution, status, ecology, and known threats, this designation should result in these bat species being considered the highest priority for funding, planning, and conservation actions. Information about status and threats to most species could result in effective conservation actions being implemented should a commitment to management exist. These species are imperiled or are at high risk of imperilment.”
In the paragraphs below we provide further definitions of legal status as they pertain to the special-status species discussed in this report or in the attached tables.

Federal Endangered or Threatened Species. A species listed as endangered or threatened under the FESA is protected from unauthorized “take” (that is, harass, harm, pursue, hunt, shoot, trap) of that species. If it is necessary to take a federally-listed endangered or threatened species as part of an otherwise lawful activity, it would be necessary to receive permission from the USFWS prior to initiating the take.

State Threatened Species. A species listed as threatened under the CESA (§2050 of California Fish and Game Code) is protected from unauthorized “take” (that is, harass, pursue, hunt, shoot, trap) of that species. If it is necessary to “take” a State-listed threatened species as part of an otherwise lawful activity, it would be necessary to receive permission from the CDFW prior to initiating the “take.”
California Species of Special Concern. These are species in which their California breeding populations are seriously declining and extirpation from all or a portion of their range is possible.

This designation affords no legally mandated protection; however, pursuant to the CEQA Guidelines (14 CCR §15380), some species of special concern could be considered “rare.” Pursuant to its rarity status, any unmitigated impacts to rare species could be considered a “significant effect on the environment” (§15382). Thus, species of special concern must be considered in any project that will, or is currently, undergoing CEQA review, and/or that must obtain an environmental permit(s) from a public agency.

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CNPS Rank Species. The CNPS maintains an “Inventory” of special-status plant species. This inventory has four lists of plants with varying rarity. These lists are: Rank 1, Rank 2, Rank 3, and Rank 4. Although plants on these lists have no formal legal protection (unless they are also State or federally-listed species), the CDFW requests the inclusion of Rank 1 species in environmental documents. In addition, other State and local agencies may request the inclusion of species on other lists as well. The Rank 1 and 2 species are defined below:
• Rank 1A: Presumed extinct in California;
• Rank 1B: Rare, threatened, or endangered in California and elsewhere; • Rank 2A: Plants presumed extirpated in California, but more common elsewhere; • Rank 2B: Rare, threatened, or endangered in California, but more common elsewhere.

All of the plants constituting Rank 1B meet the definitions of Section 1901, Chapter 10 (Native Plant Protection Act) or Sections 2062 and 2067 (CESA) of the Fish and Game Code and are eligible for State listing (CNPS 2001). Rank 2 species are rare in California, but more common elsewhere. Ranks 3 and 4 contain species about which there is some concern and are reviewed by the CDFW and maintained on “watch lists.”
Additionally, in 2006, the CNPS updated their lists to include “threat code extensions” for each list. For example, Rank 1B species would now be categorized as Rank 1B.1, Rank 1B.2, or Rank 1B.3. These threat codes are defined as follows:
• .1 is considered “seriously endangered in California (over 80% of occurrences threatened/high degree and immediacy of threat)”;
• .2 is “fairly endangered in California (20-80% of occurrences threatened)”; • .3 is “not very endangered in California (less than 20% of occurrences threatened or no current threats known).”
Under the CEQA review process only CNPS Rank 1 and 2 species are considered since these are the only CNPS species that meet CEQA’s definition of “rare” or “endangered.” Impacts to Rank 3 and 4 species are not regarded as significant pursuant to CEQA.

Fully Protected Birds. Fully protected birds, such as the White-tailed Kite (Elanus leucurus), are protected under California Fish and Game Code (§3511). Fully protected birds may not be “taken” or possessed (i.e., kept in captivity) at any time.

5. CNDDB SEARCH AND DESKTOP REVIEW RESULTS

5.1 Potential Special-Status Plants on the Subject Parcels Figure 4A provides a graphical illustration of the closest known records for special-status species within 5 miles of the Atherton town limits and helps readers visually understand the number of sensitive species that occur in the vicinity. No special-status plants have been mapped on or adjacent to any of the subject parcels. However, according to the CNPS’ Inventory and the CDFW’s CNDDB, a total of twenty-six (24) special-status plant species are known to occur within 5 miles of Atherton’s town limits (Table 1). Most of these plants occur in specialized habitats such serpentinite, chaparral, coastal dunes, vernal pools, and alkaline soil grasslands which are not present on any of these urban infill sites. Below is a discussion of special-status Biological Constraints Report
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plants that have potential to occur on one or more of the subject parcels. Please refer to Table 1 for information on the habitats these special-status plants are found in and the probability that each of these plants could be found on each of the subject parcels.

5.1.1 CONGDON’S TARPLANT
Congdon’s tarplant (Centromadia parryi ssp. congdonii) is a CNPS Rank 1B.1 species. It has no state or federal status. This annual member of the sunflower family is found in alkaline soils in grassland habitats from 0 to 755 feet of elevation. It flowers from May through November. This species is severely threatened by development.

The only CNDDB occurrence (Occurrence #54) of this species within 5 miles of Atherton’s Town limits documents 17 plants observed in 2001 in a flat, ruderal grassland area roughly 4.2 miles northeast of subject parcel V1. The annual herbaceous/grassland habitats at 23 Oakwood Boulevard, MFO-10, V1, and V3-V8 could serve as suitable habitat for this species if alkaline soil conditions are present. However, this is very unlikely due to the lack of wetland conditions or aquatic habitats at any of these subject parcels. However, special status plant surveys should be conducted by a qualified botanist during this species’ blooming period (May through November) prior to the start of any ground disturbing activities on these parcels.

If this species is observed on any of these parcels, project development plans shall consider avoidance to the extent practicable. If avoidance is not practicable while otherwise obtaining the project’s objectives, then other suitable measures and mitigation shall be implemented. Please see this report’s Recommendations section below for details.

5.1.2 CRYSTAL SPRINGS LESSINGIA
Crystal Springs lessingia (Lessingia arachnoidea) is a CNPS Rank 1B.2 species. It has no state or federal status. This annual member of the sunflower family grows primarily in serpentine grasslands but has also been found along roadsides and in cismontane woodland and coastal scrub in elevations between 195 and 655 feet.

The only CNDDB occurrence (Occurrence #7) of this species within five miles of Atherton’s town limits documents an unknown number of plants observed in May 2001 just west of Edgewood County Park roughly 0.3 mile south of the junction of Edgewood Road and I-280.

The MFO-10 site is at roughly 185 feet of elevation but all the other subject parcels with annual grassland or woodland habitats are below 150 feet. Special status plant surveys should be conducted at MFO-10 by a qualified botanist during this species’ blooming period (July through October) prior to the start of any ground disturbing activities. If this plant is found and cannot be avoided by site development, then mitigation would need to be implemented. See the Recommendations section below for details.

5.1.3 SMALL-FLOWERED MONOLOPIA
Small-flowered monolopia (Monolopia gracilens) is a CNPS Rank 1B.2 species. It has no state or federal status. This annual herb of the sunflower family is found in serpentine grassland, open chaparral, and oak and coniferous woodlands in elevations between 330 and 3,935 feet. It flowers between March and July.

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The nearest CNDDB occurrence (Occurrence #38) of this species within the last 30 years documents 11-50 plants observed in 2023 in serpentine chaparral with gravelly soils roughly 3.8 miles northwest of subject parcel MFO-10. The annual grassland habitat at MFO-10 could provide suitable habitat for this species; therefore, the presence of this plant cannot be dismissed without conducting special status plant surveys. Special status plant surveys should be conducted by a qualified botanist during this species’ blooming period (March through July) prior to the start of any ground disturbing activities on MFO-10. If this plant is found and cannot be avoided by site development, then mitigation would need to be implemented. See the Recommendations section below for details.

5.1.4 WHITE-RAYED PENTACHAETA
White-rayed pentachaeta (Pentachaeta bellidiflora) is a federal and state listed endangered species. It is also a CNPS List 1B.1 species. This slender annual herb in the sunflower family is found in grassy or rocky areas in woodlands or grassland habitats, often in serpentine soils on elevations between 115 and 2,035 feet. It blooms from March through May.

The only CNDDB occurrence (Occurrence #1) of this species within five miles of Atherton’s Town limits documents a population originally observed in 1978 and last observed in 2004 in a rocky, bare area in serpentine soils roughly four miles northwest of subject parcel MFO-10. The annual grassland areas at MFO-10, V1, and V3-V8 could provide suitable habitat for this species if there are rocky exposed areas that are not choked by annual grasses. Special status plant surveys should be conducted by a qualified botanist during this species’ blooming period (March through May) prior to the start of any ground disturbing activities on these subject parcels to determine if this plant is present or absent. If this plant is found and cannot be avoided by site development, then mitigation would need to be implemented. See the Recommendations section below for details.

5.1.5 FRAGRANT FRITILLARY
Fragrant fritillary (Fritillaria liliacea) is a CNPS Rank 1B.2 species. This plant has no federal or state status. This perennial member of the lily family is found in cismontane woodlands, coastal prairie, coastal scrub, and valley and foothill grasslands, often in serpentine soils in elevations from 10 to 1,345 feet. Fragrant fritillary is an early bloomer, flowering between February and April. It is threatened by grazing, agriculture, urbanization, and non-native plants.

The nearest CNDDB occurrence (Occurrence #35) of this species documents 25 plants observed in 2015 in a serpentine annual grassland area roughly 2.2 miles northwest of subject parcel MFO-10. Though this species is typically found in serpentine soils, the annual grassland habitat on MFO-10, V1, and V3-V8 could provide marginally suitable habitat for this species. Special status plant surveys should be conducted by a qualified botanist during this species’ blooming period (February through April) prior to the start of any ground disturbing activities at these subject parcels to determine if this plant is present or absent. If this plant is found and cannot be avoided by site development, then mitigation would need to be implemented. See the Recommendations section below for details.

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5.1.6 SAN FRANCISCO COLLINSIA
San Francisco collinsia (Collinsia multicolor) is a CNPS List 1B.2 species. It has no federal or state status. This annual plant is found in moist, shady scrub and forest habitats, sometimes in serpentine soils. It blooms between March and May and is found in elevations ranging from 100 to 900 feet.

The nearest CNDDB occurrence (Occurrence #10) of this species documents roughly 300 plants observed in 2015 in mixed foothill woodland and broadleaf forest on a steep slope roughly 4.3 miles west of subject parcel MFO-10. Potentially suitable habitat for this species is present on the annual grassland areas on MFO-10, V1, and V3-V8; its presence cannot be dismissed without conducting formal special status plant surveys. Special status plant surveys should be conducted by a qualified botanist during this species’ blooming period (March through May) prior to the start of any ground disturbing activities at these subject parcels. If this plant is found and cannot be avoided by site development, then mitigation would need to be implemented. See the Recommendations section below for details.

5.1.7 WESTERN LEATHERWOOD
Western leatherwood (Dirca occidentalis) is not a federally or California state listed species. It is a CNPS List 1B.2 species. This plant can be found in chaparral, cismontane woodlands, riparian woodlands, closed cone coniferous forest, north coast coniferous forest, riparian forests, and broad-leafed upland forest (elevation 50-395 meters). The flowering period for this deciduous shrub is from January through April.

The nearest CNDDB occurrence (Occurrence #5) of this species documents 12-50 plants observed in 2020 in thin, rocky, moist soil between foothill woodland and chaparral habitat roughly 1.5 miles south of subject parcel MFO-10. The woodland/forest habitats on MFO-10 and parcels V3-V8 may provide suitable habitat for this species. Special status plant surveys should be conducted by a qualified botanist during this species’ blooming period (January through April) prior to the start of any ground disturbing activities on these subject parcels. If this plant is found and cannot be avoided by site development, then mitigation would need to be implemented. See the Recommendations section below for details.

5.2 Potential Special-Status Animals on the Project Site Figure 4B provides a graphical illustration of the closest known records for special-status wildlife species within 5 miles of Atherton’s town limits helps readers visually understand the number of sensitive species that occur in the vicinity of the subject parcels. No special-status animal records have ever been mapped on or adjacent to any of the subject parcels. However, a total of 30 special-status animal species are known to occur in the region of the project site (Table 2). Due to the dense residential development surrounding all of the subject parcels, only four species have any possibility of occurring on any of them: Western Burrowing Owl (Athene cunicularia hypugaea), White-tailed Kite (Elanus caeruleus), pallid bat (Antrozous pallidus), and San Francisco dusky-footed woodrat (Neotoma fuscipes annectens). These species are discussed in further detail below.

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5.2.1 WESTERN BURROWING OWL
The Western Burrowing Owl (Athene cunicularia hypugaea) is a California species of special concern.” Its nest, eggs, and young are also protected under California Fish and Game Code (§3503, §3503.5 and §3513). The Burrowing Owl is also protected from direct take under the Migratory Bird Treaty Act (50 CFR 10.13). Finally, based upon this species’ rarity status, any unmitigated impacts to rare species would be considered a “significant effect on the environment” pursuant to §21068 of the CEQA Statutes and §15382 of the CEQA Guidelines.

Thus, this owl species must be considered in any project that will, or is currently, undergoing CEQA review, and/or that must obtain an environmental permit(s) from a public agency. When these owls occur on project sites, typically, mitigation requirements are mandated in the conditions of project approval from the CEQA lead agency.

Burrowing Owl habitat is usually found in annual and perennial grasslands, characterized by low-growing vegetation. Often, the burrowing owl utilizes rodent burrows, typically ground squirrel burrows, for nesting and cover. They may also on occasion dig their own burrows or use man-made objects such as concrete culverts or rip-rap piles for cover. They exhibit high site fidelity, reusing burrows year after year. Occupancy of suitable Burrowing Owl habitat can be verified at a site by observation of these owls during the spring and summer months or, alternatively, its molted feathers, cast pellets, prey remains, eggshell fragments, or excrement (whitewash) at or near a burrow. Burrowing Owls typically are not observed in grasslands with tall vegetation or wooded areas because the vegetation obscures their ability to detect avian and terrestrial predators. Since Burrowing Owls spend most of their time sitting at the entrances of their burrows, grazed grasslands seem to be their preferred habitat because it allows them to view the world at 360 degrees without obstructions.

The nearest CNDDB record of this species (Occurrence #27) documents one adult observed in winter of 2000 and 2003 above a trail through the restored San Mateo landfill area in San Mateo Shoreline Park roughly three miles east of subject parcel MFO-10. The annual grassland habitat at the north end of MFO-10 could provide suitable wintering or breeding burrows for this species.

Based on records for Western Burrowing Owl in this area and the potential habitat found on subject parcel MFO-10, a preconstruction survey for burrowing owls should be conducted prior to commencement of ground disturbing activities. See the Recommendations section below for details.

5.2.2 WHITE-TAILED KITE
The White-tailed Kite (Elanus caeruleus) is a “Fully Protected” species under the California Fish and Game Code (§3511). Fully protected birds may not be “taken” or possessed (i.e., kept in captivity) at any time. It is also protected under the federal Migratory Bird Treaty Act (50 CFR

10.13) and its eggs and young are protected under California Fish and Game Code (§3503, 3503.5). The White-tailed Kite is typically found foraging in grassland, marsh, or cultivated fields where there are dense-topped trees or shrubs for nesting and perching. They nest in a wide variety of trees of moderate height and sometimes in tall bushes, such as coyote bush (Baccharis pilularis). Native trees used are live and deciduous oaks (Quercus spp.), willows (Salix spp.), cottonwoods (Populus spp.), sycamores (Platanus spp.), maples (Acer spp.), toyon (Heteromeles Biological Constraints Report
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arbutifolia), and Monterey cypress (Cupressus macrocarpa). Although the surrounding terrain may be semi-arid, kites often reside near water sources, where prey is more abundant. The particular characteristics of the nesting site do not appear to be as important as its proximity to a suitable food source. Kites primarily hunt small mammals, with California meadow voles accounting from between 50-100% of their diet (Shuford 1993).

The nearest CNDDB record (Occurrence #87) for this species is located approximately 4.0 miles northwest of the subject parcel MFO-3. This record is from 1971 and documents three nesting pairs observed in an area of coyote brush surrounded by salt marsh habitat. This species could be encountered on any of the subject parcels that have suitable nesting trees in proximity to food and water sources.

Prior to any tree removal or earthwork that would be conducted during the nesting season (February 1 through August 31), M&A recommends that a nesting bird survey be conducted on any of the subject parcels within 15 days of the commencement of work. If active bird nests are identified, then mitigation would need to be implemented. See the Recommendations section below for details.

5.2.3 PALLID BAT
The pallid bat (Antrozous pallidus) is a California “species of special concern.” It has no federal status. The “species of special concern” status designation does not provide any special legally mandated protection for this bat species. However, this status designation likely meets the definition of “rare” pursuant to the California Environmental Quality Act (CEQA) (14 CCR §15380(2)(A)). As such, potential impacts to this bat species should be considered during any CEQA review. Any unmitigated impacts to this species would likely be regarded as a significant adverse impact pursuant to CEQA (§21068).

This bat is a locally common species of low elevations in California. It occurs throughout California except for the high Sierra Nevada from Shasta to Kern Counties, and the northwestern corner of the state from Del Norte and western Siskiyou counties to northern Mendocino County.

It occurs in a wide variety of habitats. It is most common in open, dry habitats with rocky areas for roosting. Day roosts are in caves, crevices, mines, and occasionally in hollow trees and buildings. Roost must protect bats from high temperatures. Night roosts may be in more open sites such as porches and open buildings. Pallid bat is a social species that roosts in groups of 20 or more.

The closest known CNDDB record (Occurrence #297) for the pallid bat is from 1960 and documents one male adult collected in woodland habitat roughly 1.7 miles west of subject parcel MFO-10. As abandoned buildings and trees can provide suitable roosting habitat for this species, impacts to pallid bat cannot be ruled out. Preconstruction bat surveys should be conducted by a qualified biologist prior to development or building demolition on any of the subject parcels. If this species is found during preconstruction surveys, then mitigation would need to be implemented. See the Recommendations section below for details.

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5.2.4 SAN FRANCISO DUSKY-FOOTED WOODRAT
Hooper (1938) described 11 subspecies of the dusky-footed woodrat. The San Francisco duskyfooted woodrat (Neotoma fuscipes annectens) is one of the 11 described subspecies. The duskyfooted woodrat is found in forested, wooded, and riparian habitats throughout much of California, the Willamette Valley of Western Oregon, and northern Baja California (Carraway and Verts 1991). In the San Francisco Bay Area, they have particular affinities with poison oak in riparian settings but are also frequently found in the South San Francisco Bay area high in California live oak canopies typically towards the outer branches (S. Lynch pers. observations).

Nests are typically constructed on or just off the ground in thick poison oak, willows, or other within other dense vegetation.

Dusky-footed woodrats are medium-sized rodents ranging from 200- 400g. The head and body length range from 7 3/5 to 9 inches (193-229 mm) long with a tail length of 6 4/5 to 8 2/3 inches (173-220 mm). The body coloring is brown/grey with white/grey underside and white/dusky coloring on feet. Dusky-footed woodrats have a hairy, brown tails with light undersides, and large ears (Burt and Grossenheider 1980).

Woodrats are, for the most part, generalist herbivores. They consume a wide variety of nuts and fruits, fungi, foliage, and some forbs (Linsdale and Tevis, Jr. 1951). Dusky-footed woodrats are sometimes called packrats attributable to their behavior of collecting bobbles, bottle caps, pieces of deflated shiny helium balloons, and other man-made objects. These artifacts are placed within their relatively large stick nests, some of which can last for twenty or more years.

The closest known CNDDB record for this species (Occurrence #21) is from 2016 and documents seven nesting adult woodrats captured and relocated in riparian and ruderal grassland habitat along a drainage channel roughly 3.4 miles south of subject parcel V6. The forest and woodland habitats on subject parcels V4, V5, and V6 could provide suitable nesting habitat for this rodent species. Preconstruction woodrat midden surveys should be conducted prior to commencement of ground disturbing activities or vegetation removal on subject parcels V4, V5, and V6. If this species is found during preconstruction surveys, then mitigation would need to be implemented. See the Recommendations section below for details.

5.2.5 NESTING BIRDS
Passerine birds (songbirds) and raptors (i.e., birds of prey), their active nests, eggs, and young are protected under California Fish and Game Code (§3503 and §3503.5). Thus, prior to any tree removal or earthwork that would be conducted during the nesting season (February 1 through September 1) that could disturb nesting birds (for example, ground vibrations from grading equipment will cause some birds to abandon their nests), M&A recommends that preconstruction nesting bird surveys be conducted within 7 days prior to any proposed ground disturbance (grading, paving, building demolition) or vegetation removal (including grubbing and brush clearing) on subject parcels requiring nesting bird surveys as indicated on Table A if this disturbance would occur between February 1st and September 1st (the nesting season).

If active bird nests are identified onsite during preconstruction surveys, then mitigation would need to be implemented. See the Recommendations section below for details.

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6. STATE AND FEDERAL REGULATIONS PERTINENT TO THE SUBJECT

PARCELS
There are many state and federal regulations in place that protect our waterways, native plants and wildlife, and endangered species. Those regulations relevant to the subject parcels and the proposed project are discussed below. There is not a discussion of the Federal or California Endangered Species Acts in this report because the subject parcels do not provide habitat for any federally- or state-listed species, as stated above.

6.1 Federal Migratory Bird Treaty Act
The Migratory Bird Treaty Act of 1918 (16 U.S.C. §§ 703-712, July 3, 1918, as amended 1936, 1960, 1968, 1969, 1974, 1978, 1986 and 1989) makes it unlawful to “take” (kill, harm, harass, shoot, etc.) any migratory bird listed in Title 50 of the Code of Federal Regulations, Section

10.13, including their nests, eggs, or young. Migratory birds include geese, ducks, shorebirds, raptors, songbirds, wading birds, seabirds, and passerine birds (such as warblers, flycatchers, swallows, etc.).

6.1.1 APPLICABILITY TO THE PROPOSED PROJECT
Raptors such as White-tailed Kite, Red-tailed Hawk, and Red-shouldered Hawk could nest on the subject parcels that still contain natural habitats. These raptors (birds of prey) would be protected by the Migratory Bird Treaty Act. Also, common songbirds that nest on man-made structures proposed for demolition or on the subject parcels with natural habitats would be protected pursuant to this Act. As long as there is no direct mortality of species (including their eggs or young) protected pursuant to this Act caused by development of any of the subject parcels, there should be no constraints to development. To comply with the Migratory Bird Treaty Act, preconstruction surveys would have to be conducted for nesting birds (including raptors) if any work is proposed on the subject parcels during the nesting season (February through August) and all active nest sites (nests with viable eggs or young) would have to be avoided while such birds were nesting. Upon completion of nesting, the work could commence as otherwise planned.

6.2 California Fish and Game Code § 3503, 3503.5, 3511, and 3513 California Fish and Game Code §3503, 3503.5, 3511, and 3513 prohibit the “take, possession, or destruction of birds, their nests or eggs.” Disturbance that causes nest abandonment and/or loss of reproductive effort (killing or abandonment of eggs or young) is considered “take.” Such a take would also violate federal law protecting migratory birds (Migratory Bird Treaty Act).

All raptors (that is, hawks, eagles, owls) their nests, eggs, and young are protected under California Fish and Game Code (§3503.5). Additionally, “fully protected” birds, such as the white-tailed kite and golden eagle, are protected under California Fish and Game Code (§3511). “Fully protected” birds may not be taken or possessed (that is, kept in captivity) at any time.

6.2.1 APPLICABILITY TO THE PROPOSED PROJECT
Raptors that could be impacted by the project include White-tailed Kite, Red-tailed Hawk, and Red-shouldered Hawk. These raptors and many common passerine birds could nest on the subject parcels. If any tree removal or site work would happen between February 1 and Biological Constraints Report
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September 1st, preconstruction surveys would have to be conducted for nesting birds (including raptors) to ensure that there is no direct take of these birds, or their eggs or active nests, as applicable, during the construction of the proposed project. Any active nests that are found during preconstruction surveys would have to be avoided by the proposed project. Suitable nondisturbance buffers would be established around nest sites until the nesting cycle is complete.

6.3 The Clean Water Act

6.3.1 SECTION 404 OF THE CLEAN WATER ACT
Congress enacted the Clean Water Act “to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters” (33 U.S.C. §1251(a)). Pursuant to Section 404 of the Clean Water Act (CWA) (33 U.S.C. 1344), the U.S. Army Corps of Engineers (Corps) regulates the disposal of dredged or fill material into “waters of the United States” (33 CFR Parts 328 through 330). This requires project applicants to obtain authorization from the Corps prior to discharging dredged or “fill” materials into any water of the United States.

In the published 2023 rule from the Federal Register, the term “waters of the United States” is defined as:

1. Waters which are:
a. currently used, or were used in the past, or may be susceptible to use in interstate or foreign commerce, including all waters which are subject to the ebb and flow of the tide;
b. The territorial seas; or
c. Interstate waters;

2. Impoundments of waters otherwise defined as waters of the United States under the definition, other than impoundments of waters identified under paragraph (a)(5) of this section;

3. Tributaries of waters identified in (a)(1) or (2), (4), or (6) of this section that are relatively permanent, standing or continuously flowing bodies of water;

4. Wetlands adjacent to the following waters:
i. Waters identified in paragraph (a)(1) of this section; or ii. Relatively permanent, standing or continuously flowing bodies of water identified in paragraph (a)(2) or (a)(3) of this section and with a continuous surface connection to those waters;

5. Intrastate lakes and ponds not identified in paragraphs (a)(1) through (4) of this section that are relatively permanent, standing or continuously flowing bodies of water with a continuous surface connection to the waters identified in paragraph (a)(1) or (a)(3) of this section.

6.3.2 SECTION 401 OF THE CLEAN WATER ACT
The State Water Resources Control Board (SWRCB) and the California Regional Water Quality Control Board (RWQCB) regulate activities in "waters of the State" (which includes wetlands) through Section 401 of the Clean Water Act. While the Corps administers a permitting program that authorizes impacts to waters of the U.S., including wetlands and other waters, any Corps permit authorized for a proposed project would be inoperative unless it is a Nationwide Permit Biological Constraints Report
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(NWP) that has been certified for use in California by the SWRCB, or if the RWQCB has issued a project specific certification of water quality. Where a project will result in dredge or fill of nonfederal waters of the State (that is, a water outside of the Corps’ jurisdiction), the RWQCB will authorize those fills through waste discharge requirements issued under the Porter Cologne Water Quality Control Act.

On April 2, 2019, the SWRCB adopted a State-level definition of “wetlands,” which definition is broader than the federal definition in that unvegetated areas may be considered a wetland water of the State. As a part of the same policy, the SWRCB adopted permit procedures and standards governing the discharge of dredged or fill material into wetlands and other waters of the State. The policy includes, among other things, requirements for analyses to identify the least environmentally damaging practicable alternative (LEDPA) and compensatory mitigation standards including a minimum 1:1 ratio for wetlands and streams, and full functional replacement of all waters on top of this minimum where applicable.

6.3.3 APPLICABILITY TO THE PROPOSED PROJECT
M&A reviewed Google Earth aerial imagery, U.S. topographic maps, and the USGS’s Inventory Wetlands Mapper (USFWS 2003) to look for any evidence of wetland or “other waters of the U.S./State on any of the subject parcels. No evidence of aquatic resources of any kind on any of the subject parcels was found. Based on this review, M&A does not believe that any of these subject parcels have any Corps or RWQCB jurisdictional features.

6.4 Town of Atherton Tree Ordinance
Section 8.10 of the Town of Atherton Municipal Code provides for the protection and preservation of “Heritage trees” in the Town of Atherton, and removal or destruction of a Heritage tree requires a permit issued in accordance with section 8.10.040 of the Municipal Code (Title 8, Chapter 8.10 Removal of and Damage to Heritage Trees).

Section 8.10.020 defines a “Heritage tree” as:

1. A tree meeting any of the following conditions:
a. An oak tree (Quercus lobata, Quercus agrifolia or Quercus douglasii) located anywhere on a lot, that has a minimum trunk circumference of forty-eight inches or diameter of fifteen and two-tenths inches (15.2 inches diameter at breast height), as measured at fifty-four inches above the natural grade.
b. A tree located outside the main buildable area that has a minimum trunk circumference of forty-eight inches or diameter of fifteen and two-tenths inches, as measured at fifty-four inches above the natural grade.
c. A split trunk or low-branching tree located outside the main buildable area that has a minimum trunk circumference of forty-eight inches or diameter of fifteen and twotenths inches, as measured at fifty-four inches above the natural grade. If the trunk branches or splits below this point, the smallest circumference or diameter below the lowest branch shall be measured.
d. A multi-stemmed tree located outside the main buildable area that has a total trunk circumference of forty-eight inches or total diameter of fifteen and two-tenths inches Biological Constraints Report
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when calculated as follows: considering all the branches at fifty-four inches above natural grade, add the measurement of the largest branch to one-half the measurement of each additional branch. Reference the Guide for Plant Appraisal authored by representatives to the Council of Tree and Landscape Appraisers.

2. A tree so designated by the city council, based upon findings that the particular tree is unique and of importance to the public due to its unusual age, appearance, location or other factors;

3. A tree that has been removed without a permit that cannot be measured pursuant to subsection (L)(1) of this section will be presumed to have been a heritage tree if it meets any of the following criteria:
a. The tree has a stump of at least seventeen and three-quarters inches in diameter as measured at the natural grade;
b. The tree is a native oak with a minimum of seventy-five years of age; c. The tree is any other species of tree with a minimum of forty-five years of age, unless otherwise specified in this section;
d. The tree is a redwood with a minimum age of thirty years of age; e. In the absence of remaining physical evidence, photographs and other circumstantial evidence of characteristics, including but not limited to height, canopy dimensions, and similar trees in the immediate area may be used to create a presumption that the tree was a heritage tree.

4. Exemptions. The trees listed below shall not be classified as heritage trees, regardless of their size or age, nor shall they be used for replacement plantings:
a. Bailey acacia (Acacia bailenyana)
b. Green wattle (Acacia decurrens)
c. Black acacia (Acacia melanoxylon)
d. Tree of heaven (Ailanthus altissima)
e. Mimosa (Albizia julibrissin)
f. Eucalyptus—Any species
Section 8.10.030 Prohibitions and protections
A. No person shall remove a heritage tree unless a permit has first been issued in accordance with Section 8.10.040.

B. All heritage trees must be shown and designated on every plot map that may be required by the town in connection with any application for a subdivision, variance, use permit, special structures permit, or building permit. In addition, a heritage tree protection and preservation plan may be required with each application, as determined by the town arborist.

The heritage tree protection and preservation plan shall adhere to the specifications found in the town’s current heritage tree preservation standards and specifications document. Said plan shall also show heritage trees which border the development area but are on a Biological Constraints Report
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neighboring property or share a border within fifteen feet of the property line and shall include neighbor notification as prescribed in the town’s current heritage tree preservation standards and specifications document.

C. No person shall disturb and/or damage a heritage tree by any means whatsoever, including, without limitation, those actions defined in Section 8.10.020(I), or conduct any prohibited activities within the defined TPZ as specified in the town’s current tree preservation standards and specifications document, unless a permit has first been issued by the town. Staff-level decisions about the TPZ may be appealed to the planning commission within ten days of the decision in writing to the town.

D. The provisions of this chapter shall not be deemed to repeal or otherwise affect the provisions of Chapter 8.08, relating to dead or dangerous trees (Ord. 641 § 1 (Exh. A (part)), 2020; Ord. 547 § 1, 2004; Ord. 533 § 2, 2002; Ord. 522 § 1, 2001; Ord. 444 § 3, 1989).

8.10.040 Permit process.

A. The application for a heritage tree removal permit shall be filed with the building department on a prescribed form. The building department may require the applicant, at the applicant’s expense, to furnish a written report from a certified arborist.

B. If the heritage tree which is the subject of an application meets the requirements as set forth in this section and is determined by staff to be a dead or dangerous tree as defined in Section 8.10.020(E) and pursuant to Chapter 8.08, based upon a review of the permit application and the inspection report, then the building department shall grant the permit and attach reasonable conditions to ensure compliance with the intent and purpose of this chapter such as, but not limited to, requiring replacement of the tree or trees removed with plantings acceptable to the building department. Such replacements shall not require submittal of a bond.

C. If the building department determines that the tree does not meet the requirements of a dead or dangerous tree and if the applicant requests planning commission review for removal and/or relocation, then the application shall be referred to the planning commission for consideration at a public meeting, noticed in accordance with Section 17.06.080(B). Each application for a heritage tree removal permit shall be accompanied by a fee in an amount as set by resolution of the city council sufficient to cover all costs of processing the permit. The application for planning commission review shall contain all requested information in order to be deemed complete.

D. Planning commission shall hear all evidence presented, and shall grant the heritage tree removal permit unless it finds that the removal of the subject heritage tree would be contrary to the purpose and intent of the general plan of the town, while considering the following criteria:

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1. The probability of failure which is a function of heritage tree and site conditions such as, but not limited to, structural defects, presence of disease, species history, age or remaining life span, and varying weather conditions;

2. The probability of a public safety hazard, personal injury or significant property damage as a function of proximity to existing structures and objects of value and interference with utility services;

3. The number, species, size and location of existing trees in the area and the effect of the requested removal upon shade, noise buffers, protection from wind damage, air pollution, historic value, scenic beauty, health, safety and general welfare of the area and town as a whole;

4. Good forestry practices such as, but not limited to, the age, number of healthy trees a given parcel of land will support and/or the long-term benefits of a proposed reforestation plan relative to existing site conditions;

5. The necessity to remove or relocate the heritage tree(s) to allow for operation of existing solar panels that were installed prior to the planting of the heritage tree(s) on the subject or adjoining property; and

6. The necessity to remove the heritage tree(s) to allow reasonable use or other enjoyment of the property when there is no demonstrated feasible alternative to the removal while meeting other adopted goals and policies of the general plan to the greatest extent feasible.

E. At the discretion of the planning commission, for each heritage tree permitted to be removed the permittee may be required to plant three trees of fifteen-gallon container size, or two trees of twenty-four-inch box container size, or one tree of fifteen-gallon container size and one tree of thirty-six-inch container size. Replacement trees shall not be those listed as disfavored trees above. Where heritage oak trees are allowed to be removed from within the buildable area, they shall each be replaced with one or more trees of forty-eight-inch container size of oak species at a location approved by the planning commission. The planning commission may also attach other reasonable conditions to ensure compliance with the intent and purpose of this chapter.

F. Any person required to plant replacement trees and/or relocate a heritage tree(s) pursuant to this section shall maintain such trees in a good and healthy condition to ensure permanent establishment of said trees, to the satisfaction of the town arborist. Such person shall execute a maintenance agreement with the town for a duration of between one year and three years, at the discretion of the town arborist. Such person shall also post a maintenance bond or security deposit equal to the appraised value of each tree that is planted and/or relocated. If the condition of the replacement planting(s) is not satisfactory to the town arborist during the term of the maintenance agreement, the town may take additional steps to ensure permanent establishment of replacement trees, including planting of new trees and/or an extension of the Biological Constraints Report
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maintenance agreement and bond/security deposit. This requirement shall not apply to dead or dangerous trees.

The maintenance bond/security deposit shall be returned at permittee’s request at the termination of the maintenance agreement, subject to the approval of the town arborist. The town shall attempt to notify permittee at the address on file. If no response is received from initial town attempt by thirty days from notification, then the town shall attempt a second time to notify the permittee. If after three years from the termination of the maintenance agreement the permittee has not requested the return of the maintenance bond/security deposit, the funds shall be considered forfeited and shall be deposited into the town’s general fund and shall be purposed for projects and/or improvements as identified in the town’s current adopted capital improvement plan (CIP) and/or other adopted town plan or program.

6.4.1 HERITAGE TREES TO BE IMPACTED BY THE PROPOSED PROJECT M&A reviewed a tree survey and report completed for the property at 97 Santiago Avenue (Subject Parcel V1 on Table 1 above) in April 2022 by Kielty Arborist Services, LLC. The report states that 26 Heritage trees were observed on the property or on neighboring properties, the majority of which are native oak trees. M&A also reviewed a tree survey and report conducted at 95 Faxon Road (Subject Parcel V4 on Table 1 above) in May 2023. At the request of the landowner, that survey and report only analyzed 5 coast live oaks on the property; 4 out of the 5 trees surveyed were concluded to be Heritage trees. A Town tree inventory was also taken at the Gilmore House (MFO-8 in Table 1) and at least 13 Heritage trees were noted. No known tree surveys or reports have been conducted at any of the other subject parcels, but it is likely that several of the subject parcels contain trees that would qualify as Heritage trees under the Town of Atherton’s tree ordinance.

Tree removal permits should be obtained prior to removal of any trees that may qualify as Heritage trees based on meeting any of the conditions listed in Section 8.10.020 of the Town of Atherton’s Municipal Code (listed above).

7. RECOMMENDATIONS

1. Preconstruction nesting bird surveys should be conducted within 7 days prior to any proposed ground disturbance (grading, paving, building demolition) or vegetation removal (including grubbing and brush clearing) on subject parcels requiring nesting bird surveys as indicated on Table A if this disturbance would occur between February 1st and September 1
st, the nesting season. The nesting bird surveys should include an examination of all buildings onsite and all trees and shrubs onsite and within 200 feet of the entire subject parcel (i.e., within a zone of influence of nesting birds), not just trees slated for removal. The zone of influence includes those areas outside the project site where birds could be disturbed by earth- moving vibrations and/or other constructionrelated noise. If any active bird nests are identified onsite or within a zone of influence, a non-disturbance buffer would have to be erected around the nesting site and fenced.

The nest buffer should be staked with orange construction fencing. The buffer must be of sufficient size to protect the nesting site from construction-related disturbance and should be established by a qualified ornithologist or biologist with extensive experience working Biological Constraints Report
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with nesting birds near and on construction sites. Typically, adequate nesting buffers are 50 feet from the nest site or nest tree dripline for small birds and up to 300 feet for sensitive nesting birds that include several raptor species known from the region of the project site. Upon completion of nesting surveys, if nesting birds are identified on or within a zone of influence of the subject parcel, a qualified ornithologist/biologist that frequently works with nesting birds should prescribe adequate nesting buffers to protect the nesting birds from harm while the project is constructed.

No construction or earth-moving activity should occur within any established nest protection buffer prior to September 1 unless it is determined by a qualified ornithologist/biologist that the young have fledged (that is, left the nest) and have attained sufficient flight skills to avoid project construction zones, or that the nesting cycle is otherwise completed. In this region, most species complete nesting by mid-July. This date can be significantly earlier or later and would have to be determined by the qualified biologist. At the end of the nesting cycle, and fledging from the nest by its occupants, as determined by a qualified biologist, temporary nesting buffers may be removed, and construction may commence in established nesting buffers without further regard for the nest site.

2. The Town of Atherton has a Tree Ordinance that requires acquisition of a tree removal permit prior to removal of any potential “heritage trees.” A tree removal permit should be obtained prior to removal of any trees with a minimum trunk circumference of forty-eight inches or diameter of fifteen and two-tenths inches, as measured at fifty-four inches above the natural grade, excluding the following species: Bailey acacia (Acacia bailenyana), Green wattle (Acacia decurrens), Black acacia (Acacia melanoxylon), Tree of heaven (Ailanthus altissima) and Mimosa (Albizia julibrissin).

3. Based on records for Western Burrowing Owl in this area and the potential habitat found on subject parcel MFO-10, a preconstruction survey for burrowing owls should be conducted at MFO-10 prior to commencement of ground disturbing activities. The CDFW’s Staff Report on Burrowing Owl Mitigation (CDFG 2012) states that take avoidance (preconstruction) surveys should be conducted 14 days prior to ground disturbance. As Burrowing Owls can recolonize a site after only a few days, time lapses between project activities trigger subsequent take avoidance surveys including but not limited to a final survey conducted within 24 hours prior to ground disturbance to ensure absence of the species.

If burrowing owls are detected during preconstruction surveys, the following restricted activity dates and setback distances are recommended per the CDFG’s Staff Report on Burrowing Owl Mitigation (CDFG 2012).
a. From April 1 through October 15, low disturbance and medium disturbance activities should have a 200-meter buffer while high disturbance activities should have a 500-meter buffer from occupied nests.

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b. From October 16 through March 31, low disturbance activities should have a 50- meter buffer, medium disturbance activities should have a 100-meter buffer, and high disturbance activities should have a 500-meter buffer from occupied nests. c. No earth-moving activities or other disturbance should occur within the aforementioned buffer zones of occupied burrows. These buffer zones should be fenced as well. If Burrowing Owls were found in the proposed project area, a qualified biologist would also need to delineate the extent of Western Burrowing Owl habitat on the site.

4. The forest and woodland habitats on subject parcels V4, V5, and V6 could provide suitable nesting habitat for Dusky-footed woodrats. Prior to commencement of ground disturbing activities or vegetation removal on these subject parcels, a qualified biologist should survey all oak/bay woodland and forested habitats for evidence of nesting San Francisco dusky-footed woodrats (i.e., large stick nests). Since woodrats use their nests year-round, surveys for woodrat nests may be conducted at any time of the year. If woodrat nests are identified, they will be flagged in the field and delineated on project site maps. For any woodrat nest identified on a subject parcel, the mitigation listed below should be implemented.

If any woodrat nests are identified, CDFW should be contacted immediately to coordinate mitigation. A qualified biologist should conduct a pre-construction survey for San Francisco dusky-footed woodrat nests no more than 30 days prior to the onset of site grubbing/grading or construction activities within 50 feet of construction zones.

Identified nests should be avoided, where possible. If avoidance is not possible, the nest(s) should be manually deconstructed when helpless young are not present, typically during the non-breeding season (October through January). If it is determined that young may be present during the pre-construction survey, a suitable buffer, depending on the type of proposed impact, nest location and topography of where the nest is located, shall be established by the qualified biologist (typically ranges between 20-50 feet). This nondisturbance buffer should remain in place around the nest until the young are independent enough to successfully move from the nest to be deconstructed.

5. The trees and buildings on the subject parcels may provide roosting and maternity habitat for special-status bats including the pallid bat (Antrozous pallidus). In order to avoid impacts to roosting pallid bat or other special-status bats, building or tree removal should only be conducted during seasonal periods of bat activity: between August 31 and October 15, when bats would be able to fly and feed independently, and between March 1 and April 1st to avoid hibernating bats, and prior to the formation of maternity colonies.

Then a qualified biologist, one with at least two years of experience surveying for bats, should do preconstruction surveys for roosting bats within 14 days of starting work. If the qualified biologist finds evidence of bat presence during the surveys, then he/she should develop a plan for removal and exclusion, when there are not dependent young present.

6. Prior to the Town of Atherton’s approval of development on MFO-10, V1, and V3-V8, special-status plant surveys should be conducted in appropriate habitats during the appropriate period in which the species discussed above are most identifiable. Project Biological Constraints Report
Town of Atherton General Plan Housing Element Update Project Atherton, California
22 Monk & associates
construction should not be initiated on these subject parcels until all special-status plant surveys are completed and subsequent mitigation, if necessary, is implemented.

If special-status plant species are found during these surveys, those individuals or populations should be avoided to the maximum degree possible. If avoidance is not possible while otherwise obtaining the project’s objectives, then other suitable measures and mitigation shall be developed in consultation with the agencies that are responsible for protection of that plant species based on its protection status [i.e., Town of Atherton (for plants protected by CEQA), CDFW (plants protected by California law/regulation), or USFWS (protected by federal law/regulation)]. Appropriate mitigation prescriptions for impacts on special-status plants should be included as conditions of project approval.

Biological Constraints Report
Town of Atherton General Plan Housing Element Update Project Atherton, California
23 Monk & associates

8. LITERATURE CITED
Baldwin D.H, Goldman D.H., Keil D.J., Patterson R, Rosatti T.J., Wilken D.H. (ed.). 2012. The Jepson Manual Vascular Plants of California: Second Edition. University of California Press, Berkeley. 1568 pps.

Burt, W.H. and R.P. Grossenheider 1980. Peterson field guide to mammals. Houghton Mifflin Company, 289 pp.

Carraway, L. N., and B. J. Verts. 1991. Neotoma fuscipes. Mammalian Species 386:1-10.

CDFG (California Department of Fish and Game). 2012. Staff report on burrowing owl mitigation.

March 7, 2012. 15 pages plus appendices.

CNDDB (California Natural Diversity Data Base). 2021. RareFind 6. Computer printout for special-status species within a 3-mile radius of the project site. California Natural Heritage Division, California Department of Fish and Wildlife, Sacramento, CA.

CNPS (California Native Plant Society). 2001. Inventory of rare and endangered plants of California (sixth edition). Rare plant scientific advisory committee, David P. Tibor, convening editor. California Native Plant Society. Sacramento, CA. 338 pps.

Hooper, E.T. 1938. Geographical variation in wood rats of the species Neotoma fuscipes. Univ.

Calif. Publ. Zool., 42, 213-246.

Linsdale, J. M., and L. P. Tevis, Jr. 1951. The dusky-footed wood rat. Univ. California Press, Berkeley and Los Angeles, 664 pp.

Shuford, W.D. 1993. The Marin County Breeding Bird Atlas: A Distributional and Natural History of Coastal California Birds. California Avifauna Series 1. Bushtit Books, Bolinas, California.

U. S. Fish and Wildlife Service. National Wetlands Inventory website. https://www.fws.gov/program/national-wetlands-inventory/wetlands-mapper. U.S.

Department of the Interior, Fish and Wildlife Service, Washington, D.C. Accessed on October 30, 2023.

Habitat Probability on Project Site
Family
TaxonCommon Name Status* Flowering Period
Table 1
Special-Status Plant Species Known to Occur within 5 Miles of Atherton’s Town Limits

MONK & ASSOCIATES
Area Locations
Alismataceae
Sagittaria sanfordii Fed: -
State: -
CNPS: Rank 1B
Marshes and swamps (assorted shallow freshwater).

None. No habitat. No impacts expected. Sanford's arrowhead May-October Species occurs within 5 miles of City limits.

Alliaceae
Allium peninsulare franciscanum Fed: -
State: -
CNPS: Rank 1B.2
Cismontane woodland; valley and foothill grassland [clay, often serpentine]. 100-300 m.

None. No serpentinite likely on these urban infill parcels. No impact expected. Franciscan onion May-June Species occurs within 5 miles of City limits.

Apiaceae
Eryngium aristulatum hooveri Fed: -
State: -
CNPS: Rank 1B.1
Vernal pools. None. No vernal pool habitats or
seasonal wetland habitats within the project area. No impact expected.

Hoover's button-celery
July-July Species occurs within 5 miles of City limits.

Eryngium jepsonii Fed:

State:CNPS: Rank 1B.2
Occurs on clay in vernal pools and grassland
None. No vernal pools or seasonal wetland habitats within the project area. No impact expected. Button-celery April-August Species occurs within 5 miles of City limits.

Asteraceae
Centromadia parryi congdonii Fed: -
State: -
CNPS: Rank 1B.2
Valley and foothill grassland (alkaline).

Unlikely. Needs alkaline wetland conditions. No impact expected. Congdon's tarplant May-November Species occurs within 5 miles of City limits.

Habitat Probability on Project Site
Family
TaxonCommon Name Status* Flowering Period
Table 1
Special-Status Plant Species Known to Occur within 5 Miles of Atherton’s Town Limits

MONK & ASSOCIATES
Area Locations
Cirsium fontinale fontinale Fed: FPE
State: CE
CNPS: Rank 1B
Chaparral (openings); valley and foothill grassland; [serpentinite seeps].

None. No habitat present. No impact expected. Fountain thistle June-October Species occurs within 5 miles of
City limits.

Cirsium praeteriens Fed:

State:CNPS: Rank 1A
Biennial or perennial herb Unlikely. Only known from
historic occurrences (1897 and 1901). Believed to be extirpated. No impact expected. However, this plant will be searched for during preconstruction surveys of Palo Alto thistle
June-July Species occurs within 5 miles of City limits.

Lessingia arachnoidea Fed: -
State: -
CNPS: Rank 1B
Cismontane woodland; coastal scrub; valley and foothill grassland; [serpentinite, often roadsides].

Low. No serpentinite in the project areas but this plant has been found in other habitats and along roadcuts. Surveys necessary prior to grading/site development on MFO-10. See text.

Crystal Springs lessingia
July-October Species occurs within 5 miles of City limits.

Monolopia gracilens Fed:

State:CNPS: Rank 1B.2
Coniferous and broadleafed upland forest openings, chaparral openings, and serpentine valley and foothill grassland. Elevation 100-1200 m.

Low. MFO-10 may provide suitable habitat. Surveys necessary prior to site grading or development. See text.

Small-flowered monolopia
March-July Species occurs within 5 miles of City limits.

Pentachaeta bellidiflora Fed: FE
State: CE
CNPS: Rank 1B
Valley and foothill grassland (often serpentinite).

Low. MFO-10 may provide habitat. Surveys necessary prior to site grading or development. See text.

White-rayed pentachaeta
March-May Species occurs within 5 miles of City limits.

Boraginaceae
Plagiobothrys chorisianus chorisianus Fed: -
State: -
CNPS: Rank 1B
Chaparral; coastal prairie; coastal scrub; [mesic].

None. No chaparral, coastal prairie, or scrub habitats present on any of the subject parcels. No impact expected.

Choris's popcornflower
April-June Species occurs within 5 miles of City limits.

Habitat Probability on Project Site
Family
TaxonCommon Name Status* Flowering Period
Table 1
Special-Status Plant Species Known to Occur within 5 Miles of Atherton’s Town Limits

MONK & ASSOCIATES
Area Locations
Caryophyllaceae
Silene verecunda verecunda Fed: -
State: -
CNPS: Rank 1B
Coastal bluff scrub; chaparral; coastal prairie; coastal scrub; valley and foothill grassland.

Low. Habitats onsite not ideal but MFO-10 may provide suitable habitat. Surveys necessary. See text.

San Francisco campion
March-June Species occurs within 5 miles of
City limits.

Chenopodiaceae
Suaeda californica Fed: FE
State: -
CNPS: Rank 1B
Marshes and swamps (coastal salt).

None. No marshes on any of the subject parcels. No impact expected. California sea-blite July-October Species occurs within 5 miles of City limits.

Ericaceae
Arctostaphylos andersonii Fed: -
State: -
CNPS: Rank 1B
Broadleaf upland forest; north coast coniferous forest (openings and edges) None. No habitat present. No impact expected. Santa Cruz manzanita January-April Species occurs within 5 miles of City limits.

Arctostaphylos regismontana Fed: -
State: -
CNPS: Rank 1B
Broad-leaved upland forest; chaparral; north coast coniferous forest; [granitic or sandstone].

None. No habitat present. No impact expected. Kings Mountain manzanita January-April Species occurs within 5 miles of City limits.

Fabaceae
Astragalus tener tener Fed: -
State: -
CNPS: Rank 1B.2
Playas; mesic grasslands (adobe clay), vernal pools (alkaline).

None. No aljaline soils or vernal pools on the project site. No impact expected. Alkali milkvetch March-June Species occurs within 5 miles of
City limits.

Habitat Probability on Project Site
Family
TaxonCommon Name Status* Flowering Period
Table 1
Special-Status Plant Species Known to Occur within 5 Miles of Atherton’s Town Limits

MONK & ASSOCIATES
Area Locations
Lamiaceae
Acanthomintha duttonii Fed: FE
State: CE
CNPS: Rank 1B
Chaparral; valley and foothill grassland [serpentinite].

Low. Sighting is from 1977 and this plant is known from serpentine grassland and chaparral which is unlikely to occur on any of these urban infill parcels. No impact expected.

San Mateo thorn-mint
April-June Species is located with City limits (Occ. 2). 1977 Liliaceae
Fritillaria liliacea Fed: -
State: -
CNPS: Rank 1B.2
Coastal prairie; coastal scrub; valley and foothill grassland; [often serpentinite].

Low. Typically found on serpentine substrates. MFO-10 may provide marginal habitat. Surveys necessary prior to site grading/development.

Fragrant fritillary
February-April Species occurs within 5 miles of City limits.

Linaceae
Hesperolinon congestum Fed: FT
State: CT
CNPS: Rank 1B.1
Chaparral; valley and foothill woodland; [serpentinite].

None. No serpentinite present in the project area boundaries. No impact expected. Marin dwarf flax April-July Species occurs within 5 miles of City limits.

Malvaceae
Malacothamnus arcuatus Fed: -
State: -
CNPS: Rank 4
Chaparral. None. No chaparral within
project area. Very unlikely to occur. No impact expected. Arcuate bush mallow April-July Species occurs within 5 miles of City limits.

Orobanchaceae
Chloropyron maritimum palustre Fed: -
State: -
CNPS: Rank 1B.2
Marshes and swamps (coastal salt).

None. No habitat present. No impact expected. Point Reyes salty bird's-beak June-October Species occurs within 5 miles of
City limits.

Habitat Probability on Project Site
Family
TaxonCommon Name Status* Flowering Period
Table 1
Special-Status Plant Species Known to Occur within 5 Miles of Atherton’s Town Limits

MONK & ASSOCIATES
Area Locations
Plantaginaceae
Collinsia corymbosa Fed: -
State: -
CNPS: Rank 1B
Coastal dunes. None. No habitat present. No
impact expected. Round-headed Chinese houses April-June Species occurs within 5 miles of City limits.

Collinsia multicolor Fed: -
State: -
CNPS: Rank 1B
Closed-cone coniferous forest; shady scrub forest, coastal scrub.

Low. Though the habitat is not ideal, MFO-10 may provide suitable habitat. Surveys needed prior to site grading/development. See text.

San Francisco collinsia
March-May Species occurs within 5 miles of City limits.

Thymelaeaceae
Dirca occidentalis Fed: -
State: -
CNPS: Rank 1B.2
Chaparral; riparian, broadleaf, and coniferous woodlands and forests; [mesic locations].

Low. MFO-10 may provide woodland habitat necessary for this plant. Surveys necessary prior to site grading/development.

Western leatherwood
January-April Species occurs within 5 miles of City limits.

Habitat Probability on Project Site
Family
TaxonCommon Name Status* Flowering Period
Table 1
Special-Status Plant Species Known to Occur within 5 Miles of Atherton’s Town Limits

MONK & ASSOCIATES
Area Locations
*StatusFederal:FE - Federal EndangeredFT - Federal ThreatenedFPE - Federal Proposed EndangeredFPT - Federal Proposed ThreatenedFC - Federal Candidate State:CE - California EndangeredCT - California ThreatenedCR - California RareCC - California CandidateCSC - California Species of Special Concern CNPS Continued:Rank 2 - Plants rare, threatened, or endangered in California, but more common elsewhereRank 2A - Extirpated in California, common elsewhereRank 2B.1 - Seriously endangered in California, but more common elsewhere Rank 2B.2 - Fairly endangered in California, but more common elsewhere Rank 2B.3 - Not very endangered in California, but more common elsewhereRank 3 - Plants about which we need more information (Review List) Rank 3.1 - Plants about which we need more information (Review List) Seriously endangered in CaliforniaRank 3.2 - Plants about which we need more information (Review List) Fairly endangered in CaliforniaRank 4 - Plants of limited distribution - a watch list Rank 4.2 - Plants of limited distribution; fairly threatened in CaliforniaRank 4.3 - Plants of limited distribution; not very threatened in California CNPS:Rank 1A - Presumed extinct in CaliforniaRank 1B - Plants rare, threatened, or endangered in California and elsewhereRank 1B.1 - Seriously endangered in California (over 80% occurrences threatened/ high degree and immediacy of threat)Rank 1B.2 - Fairly endangered in California (20-80% occurrences threatened)Rank 1B.3 - Not very endangered in California (<20% of occurrences threatened or no current threats known)

*Status Habitat Closest Locations Probability on Project Site Table 2
Special-Status Wildlife Species Known to Occur Within 5 Miles of Atherton’s Town Limits Species

MONK & ASSOCIATES
Insects
Bombus crotchii
Species occurs within 5 miles of City
limits.

None. No suitable habitat on any of the subject
parcels.

Fed:

State: CC
Inhabits grassland and scrub areas, with select
food plants: Antirrhinum, Phacelia, Clarkia,
Dendromecon, Eschscholzia, and Eriogonum.

Nests underground, often in abandoned rodent
dens.

Crotch bumble bee
Other:

Bombus occidentalis
Species occurs within 5 miles of City
limits.

None. No suitable habitat on any of the subject
parcels.

Fed:

State: CC
Confined to high elevation sites and north
coast. Inhabits grassland with select food
plants: Melilotus, Cirsium, Trifolium,
Centaurea, Chrysothamnus, and Eriogonum.

Typically nests underground in abandoned
rodent burrows or other cavities.

Western bumble bee
Other:

Euphydryas editha bayensis
Species occurs within 5 miles of City
limits.

None. No suitable habitat on any of the subject
parcels.

Fed: FT
State: -
Found in serpentine grasslands around San
Francisco Bay. Dwarf plantain (Plantago
erecta) is the larvae's host plant. Owl's-clover
(Castilleja spp.) is a nectar source.

Bay checkerspot butterfly
Other:

Fish
Acipenser medirostris
Species occurs within 5 miles of City
limits.

None. No suitable aquatic habitat on any of the
subject parcels.

Fed: FT
State: -
Found in rivers, estuaries, and marine waters.

Spawns in the Sacramento River and Klamath
River. Prefers lower reaches of large rivers for
spawning. Needs swift currents and large
cobble.

Green sturgeon - Southern DPS
Other:

Spirinichus thaleichthys
Species occurs within 5 miles of City
limits.

None. No suitable aquatic habitat on any of the
subject parcels.

Fed: --
State: CT
Endemic to the Sacramento-San Joaquin River
system. Inhabits open waters in the Delta and
Suisun Bay. After spawning, larvae are
carried downstream to brackish nursery areas.

Longfin smelt
Other:

*Status Habitat Closest Locations Probability on Project Site Table 2
Special-Status Wildlife Species Known to Occur Within 5 Miles of Atherton’s Town Limits Species

MONK & ASSOCIATES
Amphibians
Aneides flavipunctatus niger
Species occurs within 5 miles of City
limits.

None. No suitable habitat on or near any of the
subject parcels.

Fed:

State:

Occurs in mixed deciduous woodland,
coniferous forests, coastal grasslands. Found
under rocks near streams, in talus, under damp
logs, and other objects. Rarely encountered
very far from water.

Santa Cruz black salamander
Other: CSC
Ambystoma californiense
Species occurs within 5 miles of City
limits.

None. No suitable aquatic breeding or upland
dispersal habitiat on any of the subject parcels.

Residential development surrounding subject
parcels serves as barriers to movement of this
species.

Fed: FT
State: CT
Found in grassland habitats of the valleys and
foothills. Requires burrows for aestivation and
standing water until late spring (May) for
larvae to metamorphose.

California tiger salamander (Cntrl CA DPS)
Other:

Dicamptodon ensatus
Species occurs within 5 miles of City
limits.

None. No suitable aquatic habitat on or near any
of the subject parcels.

Fed:

State: CSC
Inhabits wet coastal forests in or near clear,
cold permanent and semi-permanent streams
and seepages. Found from Santa Cruz County
to Mendocino County in two to three isolated
regions.

California giant salamander
Other:

Rana draytonii
Species is located with City limits (Occ.
640). 2016
None. No suitable aquatic habitat on or near any
of the subject parcels and the residential
development surrounding them serve as barriers
to movement of this species.

Fed: FT
State: CSC
Occurs in lowlands and foothills in deeper
pools and streams, usually with emergent
wetland vegetation. Requires 11-20 weeks of
permanent water for larvae development.

California red-legged frog
Other:

Rana boylii
Species occurs within 5 miles of City
limits.

None. No suitable aquatic habitat on or near any
of the subject parcels.

Fed: --
State: CE
Found in partially shaded, shallow streams
with rocky substrates. Requires perenial pools
or flowing water. Needs some cobble-sized
rocks as a substrate for egg laying. Requires
water for 15 weeks for larval transformation.

Foothill yellow-legged frog **
Other:

Reptiles
Emys marmorata
Species occurs within 5 miles of City
limits.

None. No suitable aquatic habitat on or near any
of the subject parcels.

Fed: -
State: CSC
Uncommon to common in suitable aquatic
habitat throughout CA, west of the SierraCascade crest and absent from desert regions, except the Mojave River. Associated with
permanent or nearly permanent water in a
wide variety of habitat types.

Western pond turtle
Other:

*Status Habitat Closest Locations Probability on Project Site Table 2
Special-Status Wildlife Species Known to Occur Within 5 Miles of Atherton’s Town Limits Species

MONK & ASSOCIATES
Thamnophis sirtalis tetrataenia
Species is located with City limits (Occ.
75). 1922
None. No suitable marsh or aquatic habitat on or
near any of the subject parcels.

Fed: FE
State: CE
Found in freshwater marshes, ponds, and slowmoving streams on the San Francisco peninsula. Prefers dense cover and water
depths of at least one foot.

San Francisco garter snake
Other:

Birds
Elanus leucurus
Species occurs within 5 miles of City
limits.

Very low. Preconstruction surveys will be
conducted priot to development.

Fed:

State: FP
Found in lower foothills and valley margins
with scattered oaks and along river
bottomlands or marshes adjacent to oak
woodlands. Nests in trees with dense tops.

White-tailed Kite
Other:

Haliaeetus leucocephalus
Species occurs within 5 miles of City
limits.

None. No suitable nesting habitat on any of the
subject parcels. Regardless, preconstruction
nesting bird surveys will be conducted prior to
development.

Fed: -
State: CE
Ocean shorelines, lake margins, and river
courses for both nesting and wintering. Most
nests within one mile of water.

Bald eagle
Other:

Circus hudsonius
Species occurs within 5 miles of City
limits.

None. No suitable marsh habitat on or near any
of the subject parcels. Preconstruction surveys
will be conducted prior to development.

Fed: -
State: CSC
Nests on the ground or in shrubby vegetation
typically in grasslands, fallow farm lands, near
freshwater and salt water marshes.

Northern Harrier
Other:

Coturnicops noveboracensis
Species occurs within 5 miles of City
limits.

None. No suitable marsh habitat on or near any
of the subject parcels.

Fed: -
State: CSC
Summer resident in eastern Sierra Nevada in
Mono County. Fresh-water marshlands.

Yellow rail
Other:

Laterallus jamaicensis coturniculus
Species occurs within 5 miles of City
limits.

None. No suitable marsh habitat on or near any
of the suibject parcels.

Fed: --
State: CT
Inhabits salt marshes bordering larger bays.

Prefers tidal salt marshes of pickleweed.

California Black Rail
Other:

*Status Habitat Closest Locations Probability on Project Site Table 2
Special-Status Wildlife Species Known to Occur Within 5 Miles of Atherton’s Town Limits Species

MONK & ASSOCIATES
Rallus obsoletus obsoletus
Species occurs within 5 miles of City
limits.

None. No suitable marsh habitat on or near any
of the subject parcels.

Fed: FE
State: CE
Inhabits salt water and brackish marshes with
tidal sloughs in San Francisco Bay. Prefers
dense pickleweed for cover, but forages for
invertebrates along mud-bottomed sloughs.

California Ridgway's rail
Other:

Charadrius alexandrinus nivosus
Species occurs within 5 miles of City
limits.

None. No suitable habitat on or near any of the
subject parcels.

Fed: FT
State: CSC
Prefers sandy beaches, salt pond levees, and
shores of large alkali lakes. Requires sandy,
gravelly, or friable soil for nesting.

Western snowy plover
Other:

Sterna antillarum brownii
Species occurs within 5 miles of City
limits.

None. No suitable habitat on or near any of the
subject parcels.

Fed: FE
State: CE
Breeds colonially along the coast from San
Francisco Bay to Northern Baja California.

Nests on bare or sparsely vegetated flat
substrates, such as beaches, alkali flats,
landfills, or paved areas.

California least tern
Other:

Athene cunicularia hypugaea
Species occurs within 5 miles of City
limits.

Very low. Grassland areas on MFO-10 and V1
may have marginally suitable habitat.

Preconstrucion surveys will be conducted prior
to developent of these two subject parcels.

Fed: --
State: CSC
Found in open, dry annual or perennial
grasslands, deserts and scrublands
characterized by low-growing vegetation.

Subterranean nester, dependent upon
burrowing mammals, most notably, the
California ground squirrel.

Western Burrowing Owl
Other:

Asio flammeus
Species occurs within 5 miles of City
limits.

None. No suitable habitat on any of the subject
parcels.

Fed: --
State: WL
Found in fresh and saltwater marshes; lowland
meadows; irrigated alfalfa fields. Tule
patches/ tall grass needed for nesting/daytime
seclusion. Nests on dry ground in depression
concealed in vegetation.

Short-eared owl
Other:

Geothlypis trichas sinuosa
Species occurs within 5 miles of City
limits.

None. No suitable marsh habitat on or near any
of the subject parcels.

Fed: -
State: CSC
Resident of freshwater and salt water marshes
in the San Francisco Bay region. Requires
thick, continuous cover for foraging and tall
grasses, tules, or willows for nesting.

Salt Marsh Common Yellowthroat
Other:

*Status Habitat Closest Locations Probability on Project Site Table 2
Special-Status Wildlife Species Known to Occur Within 5 Miles of Atherton’s Town Limits Species

MONK & ASSOCIATES
Melospiza melodia pusillula
Species is located with City limits (Occ.
38). 1914
None. No suitable marsh habitat on or near any
of the subject parcels.

Fed: --
State: CSC
Found in Salicornia marshes in the southern
arm of San Francisco Bay. Nests in low
Grindelia bushes and in Salicornia.

Alameda Song Sparrow
Other:

Mammals
Sorex vagrans halicoetes
Species occurs within 5 miles of City
limits.

None. No suitable marsh habitat on or near any
of the subject parcels.

Fed: --
State: CSC
Tidal salt marshes of the south San Francisco
Bay. Medium high marsh 6-8 ft above sea
level where abundant driftwood is scattered
amoung pickleweed.

Salt marsh wandering shrew
Other:

Corynorhinus townsendii
Species occurs within 5 miles of City
limits.

None. No suitable roosting habitat on any of the
subject parcels. This species is extremely
sensitive to disturbance and not expected to
occur on these urban infill sites.

Fed: --
State: CSC
Occurs in humid coastal regions of northern
and central California. Roosts in limestone
caves, lava tubes, mines, and buildings.

Extremely sensitive to disturbance.

Townsend's big-eared bat
Other: -
Antrozous pallidus
Species occurs within 5 miles of City
limits.

Very low. Preconstruction surveys will be
conducted prior to development. See text.

Fed: -
State: CSC
Occurs in deserts, grasslands, shrublands,
woodlands, and forests. Most common in dry
habitats with rocky areas for roosting. Roosts
in caves, crevices, mines, and occasionally
hollow trees. Night roosts in open areas such
as porches and open buildings.

Pallid bat
Other:

Reithrodontomys raviventris
Species occurs within 5 miles of City
limits.

None. No suitable marsh habitat on or near any
of the subject parcels. No impacts expected.

Fed: FE
State: CE
Inhabits saline marshes in the San Francisco
Estuary. Prefers pickleweed marshes.

Requires higher areas for escaping high water.

Salt marsh harvest mouse
Other:

Neotoma fuscipes annectens
Species occurs within 5 miles of City
limits.

Low. Marginally suitable habitat in the forested
areas on V4, V5, and V6. Preconstruction
surveys will be conducted prior to development.

See text.

Fed: --
State: CSC
Inhabits forests, woodlands, and chaparral
with a moderate canopy and moderate to
dense understory. Uses shredded grass, leaves,
and other material for nests.

San Francisco dusky-footed woodrat
Other:

*Status Habitat Closest Locations Probability on Project Site Table 2
Special-Status Wildlife Species Known to Occur Within 5 Miles of Atherton’s Town Limits Species

MONK & ASSOCIATES
Taxidea taxus
Species is located with City limits (Occ.
130). 1894
None. No suitable habitat on or near any of
these urban infill sites.

Fed: -
State: CSC
Most abundant in drier open stages of most
shrub, forest, and herbaceous habitats, with
friable soils. Need sufficient food, friable
soils & open, uncultivated ground. Prey on
burrowing rodents. Dig burrows.

American badger
Other:
*Status
Federal:

FE - Federal Endangered
FT - Federal Threatened
FPE - Federal Proposed Endangered
FPT - Federal Proposed Threatened
FC - Federal Candidate
FPD - Federally Proposed for delisting
State:

CE - California Endangered
CT - California Threatened
CR - California Rare
CC - California Candidate
** This frog is listed as “endangered” in the east/southern Sierra, west/central, and southern California coasts and “threatened” in the Northern Sierra and Feather River. This frog is not protected pursuant to CESA on the northern coast of California (all counties from Marin and Solano Counties north to Oregon boarder).

State:

CSC - California Species of Special Concern
FP - Fully Protected
WL - Watch List. Not protected pursuant to CEQA