2015 Annual Report for Biological Resources Monitoring€¦ · 2015 Annual Report for Biological Resources Monitoring Desert Sunlight Solar Project, Riverside County BLM CASE FILE

2015 Annual Report for Biological Resources Monitoring

Desert Sunlight Solar Project, Riverside County BLM CASE FILE NUMBER CACA-48649

Biological Opinion# FWS-ERIV-08B0789-11F0041

Prepared for: BUREAU OF LAND MANAGEMENT

Palm Springs – South Coast Field Office 1201 Bird Center Drive

Palm Springs, California 92262

Prepared by: IRONWOOD CONSULTING, INC. 1030 Nevada Street, Suite 201

Redlands, CA 92374

Desert Sunlight Solar Farm 2015 Annual O&M Biological Report ii

Table of Contents 1.0 INTRODUCTION ................................................................................................................................ 1

2.0 DESERT TORTOISE ............................................................................................................................. 2

2.1 Overview ....................................................................................................................................... 2

2.2 Survey/Monitoring Methods ........................................................................................................ 3

2.2.1 Tortoise Fence Inspections .................................................................................................... 3

2.2.2 Monitoring ............................................................................................................................ 3

2.2.3 Vegetation Transects in Tortoise Recipient Site .................................................................... 3

2.2.4 Radio Tracking ....................................................................................................................... 3

2.2.5 Health Assessments .............................................................................................................. 3

2.3 Results and Discussion .................................................................................................................. 4

2.3.1 Tortoise Fence Inspections .................................................................................................... 4

2.3.2 Biological Monitoring ............................................................................................................ 5

2.3.3 Vegetation Transects in Tortoise Recipient Site .................................................................... 5

2.3.4 Tortoise Radio Tracking ......................................................................................................... 5

2.3.5 Health Assessments .............................................................................................................. 6

2.4 Conclusion/Recommendations ..................................................................................................... 6

3.0 SALVAGED VEGETATION ................................................................................................................ 10

3.1 Overview ..................................................................................................................................... 10

3.2 Survey/Monitoring Methods ...................................................................................................... 10

3.2.1 Vegetation Salvage Area ..................................................................................................... 10

3.2.2 Castela Transplants around Visitor Center ......................................................................... 10

3.3 Results and Discussion ................................................................................................................ 10

3.3.4 Vegetation Salvage Area ..................................................................................................... 10

3.3.5 Castela Transplants around Visitor Center ......................................................................... 13

3.4 Conclusion/Recommendations ................................................................................................... 14

4.0 DESERT DRY WASH WOODLAND STUDY ....................................................................................... 14

4.1 Overview ..................................................................................................................................... 14



4.4 Conclusion/Recommendations ................................................................................................... 20

5.0 INTEGRATED WEED MANAGEMENT .............................................................................................. 21

5.1 Overview ..................................................................................................................................... 21

Desert Sunlight Solar Farm 2015 Annual O&M Biological Report iii



5.3.1 Solar Farm ........................................................................................................................... 22

5.3.2 Gen-Tie Line ......................................................................................................................... 23

5.3.3 Herbicide Use ...................................................................................................................... 23

5.4 Conclusions and Recommendations ........................................................................................... 28

6.0 RAVEN MANAGEMENT................................................................................................................... 28

6.1 Overview ..................................................................................................................................... 28


6.2.1 Incidental Sightings ............................................................................................................. 28

6.2.2 Avian Point Count Surveys................................................................................................... 29

6.2.3 Nest Surveys ........................................................................................................................ 29


6.3.1 Incidental Sightings ............................................................................................................. 31

6.3.2 Avian Point Count Survey Results ........................................................................................ 32

6.3.3 Nest Survey Results ............................................................................................................ 36

6.4 Conclusion and Recommendations............................................................................................. 38

REFERENCES ................................................................................................................................................ 39

LIST OF TABLES

Table 1. 2015 Desert Tortoise Task………………………………………………………………………………………………………..2 Table 2. Results from ELISA tests for M. testudenium and M. testudenium (2011-2015)………………….…….9 Table 3. Status of Surviving Salvaged Plants, 2015…………………………………….…………………………………….……11 Table 4. Survivorship Thresholds for Salvaged Plants………………………………………………………………………..….11 Table 5. Status of Crucifixion Thorn (Castela Emoryi), 2015………………………………………………………………....13 Table 6. Desert Dry Wash Study Health and Vigor Results………………………………………….……………………17-18 Table 7. Summary of Weed Survey Dates and Locations, 2015………………………………….…………………….……22 Table 8. Raven Detections during Avian Point Counts 2011-2015…………………………………………………………33 Table 9. Total Number of Ravens Detections at Point Counts Over Time………………………………………………33 Table 10. Raven Density Estimates by Season and Year…………………………………………………………………………34 Table 11. Estimated Density of Common ravens at Desert Center over Time………………………………………..35 Table 12. Comparison of success, failure and total number of raven nests from 2013 through 2015…….37

Desert Sunlight Solar Farm 2015 Annual O&M Biological Report iv

LIST OF FIGURES

Figure 1. Translocatee and Resident Tortoises Last Radio-tracking Locations………………………………………..7 Figure 2. Control Tortoises Last Radio-tracking Locations………………………………………………………………………8 Figure 3. Remaining Surviving Salvaged Plants………………………………………………………………………………………12 Figure 4. DDWW Study Sites ………………………………………………………………………………………………………………..19 Figure 5. Solar Farm Survey Results for Incidental Weeds January-March 2015……………………………………25 Figure 6. Gen-tie Line A-1 Survey Results for Incidental Weeds January-March 2015…………………………….26 Figure 7. Herbicide Use Areas ………………………………………………………………………………………………………….……27 Figure 8. Avian Point Count Locations associated with Desert Sunlight Solar Farm …………………………….…30 Figure 9. Raptor and Raven Nests Detected During 2015……………………………………………………………………..37

LIST OF PHOTOS Photo 1. Erosion post-rain events………………………………………………………………………………………………………….4 Photo 2. Permanent repairs of erosion ………………………………………………………………………………………………...4 Photo 3. Permanent repairs to erosion along tortoise fence inside and outside Project boundary………..5 Photo 4. Front view of 6004 carcass……………………………………………………………………………………………………...6 Photo 5. Lateral view of 6213 carcass…………………………………………………………………………………………………….7 Photo 6. Remaining Castela around the Visitor Center, December 2015………………………………………………13 Photo 7. Repeat Photograph Site #1 Palo Verde #9 - 28 December 2012…………………………………………….15 Photo 8. Repeat Photograph Site #1, Palo Verde #9 - 11 December 2015……………………………………………15 Photo 9. Repeat Photograph Site #3, Smoke Tree #3 - 28 Dec 2012…………………………………………………….16 Photo 10. Repeat Photograph Site #3, Smoke Tree #3 - 11 December 2015………………………………………….16 Photo 11. Dead plants beneath solar arrays………………………………………………………………………………………….23 Photo 12. Dead plants in retention basins…………………………………………………………………………………………….23 Photo 13. Native rubber rabbit bush (Ericameria nauseosa) affected by herbicide use…………………………24 Photo 14. Native creosote (Larea tridentata) affected by herbicide use……………………………………………….24 Photo 15. Common raven pulling apart project trash, while perched on solar panels……………………….….31

Desert Sunlight Solar Farm 2015 Annual O&M Biological Report 1

1.0 INTRODUCTION Desert Sunlight Solar Farm (Project) transitioned from the construction phase of the Project to the

Operations and Management (O&M) phase of the Project beginning on January 1, 2015 under Next Era

Energy. Biological requirements have also been phased into the requirements for O&M per the following

guiding documents of the Project:

Biological Opinion (BO)

Final Environmental Impact Statement (FEIS)

Desert Tortoise Translocation Plan (DTTP)

Vegetation Salvage Plan (VSP)

Desert Dry Wash Woodland Plan (DDWWP)

Integrated Weed Management Plan (IWMP)

Pesticide Use Proposal (PUP) and associated Environmental Assessment (EA)

Raven Management Plan (RMP)

Bird and Bat Conservation Strategy (BBCS)/Avian and Bat Protection Plan (ABPP)

Ironwood Consulting, Inc. (Ironwood) has performed all biological requirements associated with the

above plans throughout 2015 for O&M, with the exception to some tasks of the BBCS (approved in

December 2014) which replaces the older ABPP. A different consulting firm was tasked for the

requirements of the BBCS.

As the Project phased into O&M, regular biological presence also decreased at the site and occurred only

when required biological tasks were necessary. Monthly summary reports of all biological activities

completed by Ironwood were submitted to Next Era at the end of each month of activity, including all the

collected raw, unprocessed data.

Biological requirements for O&M will be discussed in this report per each biological resource.


2.0 DESERT TORTOISE

2.1 Overview

Per the BO and the DTTP, requirements for desert tortoise include tortoise fence inspections, biological

monitoring if necessary, radio tracking, and health assessments. The intention of these tasks are to

monitor the health and activity of translocated tortoises from the project site and prevent any harm to

desert tortoises during the O&M phase of activities. All desert tortoise related tasks conducted in 2015

are summarized in Table 1.

Table 1. 2015 Desert Tortoise Tasks

Time Period

2015 Tortoise Radio Tracking

Tortoise Health

Assessments Tortoise Fence Inspections

January 1/20/15 C. Hackbarth, A. Robinson - 1/20/15 C. Hackbarth, A. Robinson

February 2/17-18/15 B. Sandstrom - 2/17/15 B. Sandstrom

March

3/21-22/2015 P. Flores; 3/25-26/2015 E.

Lockward -

3/3/15 P. Pacheco, B. Sandstrom,

P. Flores

April

4/8-9/15 P. Flores, 4/14-15/15 L.Chow, 4/21-22

L. Chow & K.Hughes; 4/28-29/15 E. Lockward -

4/7/15 P. Flores, 4/22/15 K.

Hughes

May

5/6-5/11B. Sandstrom, K. Kermoian; 5/14-5/15 K.

Hughes; 5/19-5/20 L. Chow; 5/26-/27 E. Lockward

5/6-5/11 K. Kermoian, B.

Sandstrom 5/8 B. Sandstrom

June 6/3-6/4 L. Chow, 6/23-6/24 K. Hughes -

6/21-6/23 B. Sandstrom, P.

Pacheco, P. Flores

July 7/8-7/9 K. Hughes, 7/28 K. Hughes, L. Chow - 7/9, 7/20, 7/31 K. Hughes

August 8/11-8/12, K. Hughes, 8/27-8/28, K. Hughes - 8/10 K. Huges, fence repair

September 9/9-9/10 K. Hughes, 9/28-9/29 L. Chow - 9/10 K. Hughes

October

10/9-10/10 K. Hughes, 10/26 E. Locward, 10/27

K. Hughes

10/30-10/31 B.

Sandstrom, R. Woodard 10/9 K. Hughes

November 11/18-11/19 K. Hughes

11/2-11/3 C. Bedwell, L.

Chow 11/18 K. Hughes

December 12/10 L. Chow - 12/8 P. Pacheco


2.2 Survey/Monitoring Methods

2.2.1 Tortoise Fence Inspections The perimeter tortoise fence was inspected at least once a month by Ironwood biologists throughout the

year. Inspections occurred during visits to the site in conjunction with monthly inner perimeter weed

inspections and tortoise radio-tracking events. After rainstorms, if Ironwood biologists were not nearby,

onsite personnel also inspected the tortoise fence within 24 hours, as required by the BO, and contacted

Ironwood if there were any issues with the tortoise fence.

2.2.2 Monitoring The Biological Opinion states that “Authorized Biologists or Biological Monitors would be present during

all ground-disturbing construction activities that have the potential to disturb soil, vegetation, and

wildlife…to minimize incidental death and injury of desert tortoises residing in or entering the construction

or O&M disturbance areas (e.g., project sites, linear facilities, access roads). Because of this, any work or

repairs that occur outside the biologically cleared solar farm site is required to have a biological monitor.

Prior to beginning any ground disturbing activities outside the Project, biological monitors familiarized

crews with species of wildlife and plants that are of concern for the Project. Biological monitors walked

or drove ahead of crews surveying for wildlife and plants. When areas were cleared biologically, crews

were allowed to access areas and the biological monitor remained present during all ground-disturbing

activities that occurred outside the fenced project boundary to ensure that ground disturbance is minimal

and no species of concern were harmed.

2.2.3 Vegetation Transects in Tortoise Recipient Site Five baseline points were previously established at the Sunlight Recipient Site and the Chuckwalla

Control Site (10 baseline points total) and surveyed annually to measure potential changes in habitat

characteristics. Each baseline point used line-intercept transects heading east and north to record cover

estimates of each plant species detected as well as the plants found within each 5m x 50m plot. Data

was recorded on datasheets.

2.2.4 Radio Tracking There are six translocated, six resident and seven control tortoises associated with the Desert Sunlight

Solar Farm Project. These tortoises were radio tracked per the BO weekly in the spring, twice monthly in

the summer and fall, and once a month in the winter.

2.2.5 Health Assessments Comprehensive health assessments are required per the BO in the spring and fall and were conducted per

US Fish and Wildlife Service guidelines. Health exams were performed by permitted personnel only.


2.3 Results and Discussion

2.3.1 Tortoise Fence Inspections The tortoise fence remained intact throughout most of 2015 during every monthly inspection with the

exception of the summer monsoonal months of July and August. Due to heavy rain events those months,

erosion occurred on the eastern part of the permanent tortoise fence that left a small breach on the

tortoise fence. Onsite personnel inspected the fence after all rain events and temporarily blocked any

gaps in the fence with plywood until those areas could be permanently repaired (see photos 1 and 2). A

biologist also inspected areas where temporary repairs were made for any signs of tortoise entering the

site – no sign was detected.

Photo 1. Erosion post-rain events Photo 2. Permanent repairs of erosion


2.3.2 Biological Monitoring Only one biological monitoring event occurred during 2015 for O&M related to repairs to the permanent

tortoise fence on the eastern side of the Project. The monitoring event occurred on August 10, 2015

following substantial rain events earlier in the week due to some minor breeches in the tortoise fence. A

biological monitor was present to ensure that no sensitive wildlife or plants were harmed outside project

boundaries when the repair crew took equipment off site to the outer eastern boundary of the Project

site. The biological monitor ensured that no wildlife was harmed and the crew remained within the

Project right-of-way as erosion repairs occurred (see photo 3).

Photo 3. Permanent repairs to erosion along tortoise fence inside and outside project boundary

2.3.3 Vegetation Transects in Tortoise Recipient Site Vegetation transects were completed on March 13-14, 2015 by Lead Botanist Michael Honer and two

assistants. There were no significant changes noted, and data will be tabulated when tortoises are

decommissioned and processed with data collected in previous years to note potential changes since

translocation efforts began.

2.3.4 Tortoise Radio Tracking All tortoises appeared to display seasonally appropriate behavior throughout the year and were located

during each radio tracking event, with the exception of 6117, 6004, and 6213 discussed below. The last

tortoise radio tracking locations in 2015 are depicted in Figures 1 and 2.

The only tortoise that was not located during each event was resident tortoise 6117, whose transmitter

may have failed. It was last located in a burrow on April 14, 2015. Since then, the transmitter has not been

heard after much searching within and outside its range, nor has the tortoise been found occupying any

of its historical burrows. Its historical range is not large and there has been some effort during each radio

tracking event to locate the tortoise in its high fidelity burrows, but to date the effort has been

unsuccessful. Total search time for the lost tortoise has exceeded over 50 hours.


Two tortoise mortalities were detected during radio tracking events this year – one was translocatee male

tortoise 6004 and another was control male tortoise 6213. Cause of death was unclear for both tortoises,

but was suspected to be predator related. Both carcasses were left in place per agency instruction and

mortality reports were sent to agencies on August 28, 2015 for tortoise 6004 and on September 30, 2015

for 6213 following the discovery of the mortalities.

Photo 4. Front view of 6004 carcass Photo 5. Lateral view of 6213 carcass

2.3.5 Health Assessments Comprehensive health assessments performed on all transmittered tortoises in the spring and fall of

2015 did not indicate any unusual or troublesome conditions - tortoises were non-symptomatic for

upper respiratory disease, and no recent traumatic injuries were recorded. Results of all ELISA tests

performed by University of Florida for Mycoplasma agassizii and Mycoplasma testudinium are

presented in table 2.

2.4 Conclusion/Recommendations

All tortoise requirements for O&M were met during 2015. Tortoises displayed seasonally appropriate

behavior during radio tracking events, tortoise fence issues were dealt with in a timely manner, and

tortoise health results in 2015 were consistent with previous results. Radio tracking, fence inspections,

and health assessments will continue throughout the next year until decommissioning of the tortoises,

which is expected to occur in fall 2016 with agency approval.



Table 2. Results from ELISA tests for Mycoplasma testudenium and Mycoplasma testudenium (2011-2015)

KEY:

Myco

pla

sm

a

testu

den

ium

Myco

pla

sm

a

ag

gassiz

ii

Myco

pla

sm

a

testu

den

ium

Myco

pla

sm

a

ag

gassiz

ii

Myco

pla

sm

a

testu

den

ium

Myco

pla

sm

a

ag

gassiz

ii

Myco

pla

sm

a

testu

den

ium

Myco

pla

sm

a

ag

gassiz

ii

Myco

pla

sm

a

testu

den

ium

Myco

pla

sm

a

ag

gassiz

ii

Myco

pla

sm

a

testu

den

ium

Myco

pla

sm

a

ag

gassiz

ii

Myco

pla

sm

a

testu

den

ium

Myco

pla

sm

a

ag

gassiz

ii

Myco

pla

sm

a

testu

den

ium

Myco

pla

sm

a

ag

gassiz

ii

Myco

pla

sm

a

testu

den

ium

Myco

pla

sm

a

ag

gassiz

ii

6001 <32 <32 32 <32 <32 32 <32 <32 <32 <32 <32 <32 32 <32 - - - - dead 2014

6002 <32 <32 64 <32 32 32 <32 <32 <32 <32 128 <32 <32 <32 <32 32 <32 <32

6003 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 - <32 <32

6004 <32 <32 128 <32 64 <32 <32 <32 <32 <32 <32 <32 <32 <32 - <32 - - dead 2015

6005 - - 64 <32 <32 <32 <32 <32 <32 <32 <32 <32 - - <32 <32 <32 <32

6006 - - 64 <32 32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 - <32 <32

6007 - - <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 - <32 <32

6111 <32 <32 32 <32 <32 <32 <32 <32 <32 <32 32 <32 <32 <32 <32 <32 <32 <32

6114 <32 <32 <32 <32 <32 <32 <32 <32 <32 32 <32 <32 - - - - - - dead 2014

6115 <32 <32 64 <32 32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 - <32 <32

6116 <32 <32 - - <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32

6117 <32 <32 64 <32 64 32 <32 <32 <32 <32 <32 <32 <32 <32 - - - - dead/lost 2015

6119 <32 <32 - - 64 <32 <32 <32 <32 <32 32 <32 32 <32 <32 <32 <32 <32

6123 <32 <32 64 <32 32 <32 <32 <32 <32 <32 32 <32 <32 <32 <32 <32 <32 <32

6210 - - - - <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32

6211 - - - - <32 <32 <32 <32 <32 <32 32 <32 <32 <32 <32 <32 <32 <32

6212 - - - - <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32

6213 - - - - 32 <32 <32 <32 <32 32 <32 <32 32 <32 - <32 - - dead 2015

6214 - - - - 32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32

6215 - - - - 32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 32 <32 <32

6216 - - - - <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32 <32

T

RA

NSL

OC

ATE

DR

ESID

ENT

CO

NTR

OL

2011

2012

Tortoise IDTortoise

Status

FALL

2015

2014

SPRING FALL SPRING FALL SPRING FALLSPRING FALL

2013

ELIZA TiterMycoplasma

aggassizii RESULT

Mycoplasma

testudenium RESULT

<32 Negative Negative

32 Suspect Suspect

64 Positive Suspect

128 Positive Positive


3.0 SALVAGED VEGETATION

3.1 Overview

This report summarizes the status of all salvaged plants housed in the Vegetation Salvage Area and the

Visitor Center of the Desert Sunlight Solar Farm throughout 2015. These plants were all salvaged per

provisions of the Vegetation Salvage Plan (VSP) and have been in the care of the Ironwood Lead Botanist,

Michael Honer, since construction began. Detailed methods, timing, success thresholds, and adaptive

management have been reported in quarterly and annual reports throughout construction and methods

will remain the same throughout the O&M period.


3.2.1 Vegetation Salvage Area At the beginning of 2015, a total of 85 plants remained on the Vegetation Salvage Area. All of these

plants were extracted per the VSP from the solar site during construction and transplanted to the area.

Many additional plants (mostly cacti) were also extracted during construction, but were subsequently

donated to various entities (detailed in previous year-end reports).

The health and vigor monitoring for the remaining plants onsite was conducted by Ironwood Lead Botanist

Michael Honer at the Vegetation Salvage Area near the Visitor Center.

Salvaged plants were placed in four categories: robust, fair, poor, or dead depending on the percentage

of the plant that appears alive as described in the Vegetation Salvage Plan.

3.2.2 Castela Transplants around Visitor Center Before construction in 2011, vegetative cuttings from several crucifixion thorn plants (Castela emoryi)

were taken from the Desert Sunlight Solar Farm site as well as surrounding areas. These cuttings were

propagated at the Rancho Santa Ana Botanic Garden (RSABG) to appropriate size for transplant. In

November 2014, these crucifixion thorn propagules were brought to the Project’s Visitor Center and

experimentally transplanted following recommendations of RSABG nursery staff.

These plants have been caged against herbivory and RSABG advised against watering these plants until

late spring 2015, so all the dripline emitters near these plants have only been unplugged for a brief period

in May 2015 during the second quarter’s health assessments. Dripline emitters were capped again in

anticipation of summer monsoonal rains and continue to remain capped.


3.3.4 Vegetation Salvage Area All plants appear to have established nicely and should require little maintenance going forward. The

cacti seem to be surviving the severe continuing drought across the region, and should not need

supplemental watering. There were a few scattered summer monsoon events this summer, which

provided adequate natural watering for all the plants, so no additional watering occurred for the

remainder of 2015. The status of surviving plants during the last visit of 2015 is summarized in Table 3.


Table 3: Status of Surviving Salvaged Plants, 2015

Three salvaged plant mortalities were recorded in 2015:

1 Mamillaria tetrancistra was succumbed to rodent herbivory (March 2015)

1 Cylindropuntia echinocarpa succumbed to long-term termite damage (October 2015)

1 Fouquieria splendens succumbed to a boring insect infestation (October 2015)

To date, survivorship thresholds for all salvaged plants remains within the threshold required in the VSP

and is summarized in Table 4.

Table 4. Survivorship Thresholds for Salvaged Plants

Scientific name Common nameTotal

survivingRobust Fair Poor Dead

Cylindropuntia echinocarpa Golden cholla 37 29 7 2 1

Cylindropuntia ramocissima Pencil cholla 14 14

Opuntia basilaris Beavertail cactus 4 3 1

Mammillaria tetrancistra Nipple cactus 4 4 1

Coryphantha alversonii Foxtail cactus 1 1

Fouquieria splendens Ocotillo 22 22 1

TOTAL ALL PLANTS 82 73 8 2 3

DSSF Vegetation Salvage Area - Surviving Transplant Status - December 11, 2015

Salvaged Plants

Original

Number of

Salvaged

Plants

Plant

Mortalities

(2011-2015)

Surviving

Number of

Plants

(December

2015)

Survivorship

Threshold

Required

Survivorship

Achieved to

Date

Cactus 72 12 60 50% 75%

Ocotillo 29 7 22 75% 83%


Figure 3. Remaining Surviving Salvaged Plants


3.3.5 Castela Transplants around Visitor Center To date, 14 of these plants appear to be surviving. General Health and Vigor monitoring as of October 8,

2015 are summarized in Table 3.

Table 5. Status of Crucifixion Thorn (Castela emoryi), 2015

There were significant mortalities of many of these plants over the summer of this year - all of the

smaller plants and some larger plants died. Although watering of these plants occurred in May 2015,

and several monsoonal storms watered the plants over the summer, most plants have perished. There

is no supportable explanation for this beyond the assumption that these plants do not survive

transplantation well. During transplantation, very delicate minor root growth on the smaller plants

were observed, which sometimes detached during planting. It is suspected that these plants were not

developed enough to transplant effectively. The larger plants had a much more developed root mass,

which appeared to have remained intact during the transplantation. Some of these larger plants are still

doing quite well, leafing out and growing new stems.

There were no success thresholds assigned to these plants in the Vegetation Salvage Plan, but the

intention is to keep good data of all of these Castela maintaining some genetic participation in the ecology

of the Chuckwalla Valley.

Photo 6. Remaining Castela around the Visitor Center, December 2015

Robust Fair Poor Dead Total

8 3 1 56 68

Castela Status - DSSF Visitor Center - December 2015



The on-going responsibilities for the salvaged vegetation will be quarterly maintenance and monitoring of

plants in the Plant Salvage Area and the Castela transplants by the Visitor Center, which includes judicious

watering as needed and checking for any pest infestations or any additional unanticipated damage. No

additional watering is proposed in anticipation of the coming rainy season in 2016. Sufficient rainfall is

anticipated that will bolster the remaining survivors into a more robust state. Success thresholds have

been met but close attention should be given to all the species in an effort to continue to give them the

best chance of survival.

4.0 DESERT DRY WASH WOODLAND STUDY

4.1 Overview Desert Dry Wash Woodland (DDWW) is designated as an important vegetation type that qualifies for

monitoring and protection per The Northern and Eastern Colorado Desert Coordinated Management Plan

("NECO" Bureau of Land Management, 2002). In 2012, First Solar began preparations for drilling a second

well near the eastern boundary of the solar site, situated near the Pinto Wash DDWW. This action

triggered the need and timeline for monitoring potential effects of groundwater drawdown on the trees

in Pinto Wash.

This study is intended to monitor DDWW trees near the construction well to see if groundwater drawdown

by the well is affecting them. Well production began in Winter 2012 and ended in Summer 2014. To date,

all the trees are surviving, and many are thriving. There is no evidence that well activity has adversely

affected these trees.


This ongoing study complies with the provisions outlined in the Desert Dry Wash Woodland Monitoring

and Reporting Plan (Ironwood Consulting, Inc., 2011b). Several aspects of the original design and timing

of this study have been altered to conform to conditions observed in the study area, and to improve

efficiency of sampling. Details of the new study design and its departure from the original plan were

coordinated with the BLM and outlined in the 2012 Annual Report for Biological Resources Monitoring for

Desert Sunlight Solar Farm (Ironwood Consulting, 2012), which includes qualitative health and vigor

characteristics and photographs of each species in full, north facing.



After nearly 3 years of monitoring the 80 study trees across all four sites, all trees remain alive although

2 smoke trees appear to be in poor health 24 trees exhibited some loss of live branches, as compared

with baseline measurements taken in late 2012. Significant loss is defined as a loss of 10% or more loss

of "live" branches, although percent loss varied from 5% to 75%.

The greatest loss of tissue across all sites was on smoke trees (21 of 40), with significant decline

observed on 2 smoke trees in the control site, 3 smoke trees at site #2, and 3 smoke trees at site #1.

The only losses of palo verdes were 2 trees at the control site and 1 tree on site #1. However, no palo

verde loss was greater than 20%.

Normal (but modest) patterns of flowering and fruiting for each species took place each year, with the

majority of action happening in late spring into early summer. By December 2015, most trees had

already flowered, set, and dropped seed. Occasional summer monsoonal storms grazed the area this

summer, which accounts for modest leafing-out of many of the palo verdes. There were no noticeable

diseases or insect infestations on any of the trees.

Photos 7 and 8. Example of repeat photographs of two study trees: 28 Dec 2012 and 11 December 2015.

Site #1, Palo Verde #9: 75% live tissue (no change)


Photos 9 and 10. Example of repeat photographs of two study trees: 28 Dec 2012 and 11 December

2015. Site #3, Smoke Tree #3 showing loss of about 10% live branches since baseline study

This study is intended to monitor trees that might be "phreatophytic" near the well to see if groundwater

drawdown is harming them. This study to date has shown no significant changes that could be attributable

to water table drop associated with the well installed near DDWW on the Project.

A number of factors may also affect the efficacy of this study, including:

If these trees are actually obligate phreatophytes, what would be the expected lag time be before

observing any noticeable change in their health? If they are facultative phreatophytes, how could

a decline in health be definitively attributed to groundwater drawdown versus a prolonged

drought?

Strong late summer-early fall monsoonal storms covered the Pinto Wash area in 2011, 2012 013,

and 2015 producing strong surface flows and potential infiltration. Could these storms "mask" any

effects of drought or groundwater drawdown?

Total winter precipitation in the years since the Project started has been poor, and especially

below average in the last four years. Could this lack of seasonal rainfall be the cause of the die-

backs that have been recorded?

What is the effect of existing agricultural wells near Pinto Wash?


Table 6. Desert Dry Wash Study Health and Vigor Results (All measurements are in percentages with yellow highlights indicating loss of >10% branch tissue)

DATE

% % % % % % % % % % % %

alive leaf flw / frt alive leaf flw / frt alive leaf flw / frt alive leaf flw / frt

W1PV01 90 1 90 80 90 5

W1PV02 40 1 40 40 40

W1PV03 65 2 65 65 2 65

W1PV04 90 30 90 90 7 85 25

W1PV05 65 70 75 65

W1PV06 70 70 50 70

W1PV07 75 1 75 75 75

W1PV08 90 40 80 90 2 80 15

W1PV09 75 75 70 75

W1PV10 90 1 90 90 2 90

W1STO1 90 85 90 60

W1ST02 75 75 75 70

W1ST03 90 85 75 40

W1ST04 90 90 80 75

W1ST05 95 85 90 75

W1ST06 60 75 60 20

W1ST07 95 90 95 70

W1ST08 75 75 75 75

W1ST09 95 95 95 75

W1ST10 75 75 75 75

W2PV01 75 1 75 75 1 75

W2PV02 90 90 90 10 90 10

W2PV03 45 45 45 45

W2PV04 95 95 95 95

W2PV05 65 1 65 65 65 5

W2PV06 65 65 65 65

W2PV07 75 4 75 1 75 30 75 10

W2PV08 65 65 65 65

W2PV09 70 70 70 10 70 10

W2PV10 65 65 65 65

W2ST01 60 65 60 50

W2ST02 100 98 95 70

W2ST03 70 5 70 70 65

W2ST04 75 8 75 75 70

W2ST05 60 1 60 60 1, 0 60

W2ST06 85 80 50 30

W2ST07 60 60 60 45

W2ST08 55 55 55 55

W2ST09 70 5 70 50 10

W2ST10 55 65 55 55

Plant ID

Site #1: Closest to well (480m)

Site #2: 783m from well

Winter 2012 Winter 2013 Winter 2014 Winter 2015

BASELINE H&V H&V H&V H&V


Table 6. Desert Dry Wash Woodland Study Health and Vigor Results (continued)

DATE

% % % % % % % % % % % %

alive leaf flw / frt alive leaf flw / frt alive leaf flw / frt alive leaf flw / frt

W3PV01 85 25 80 1 85 30 85 20

W3PV02 45 45 45 5 45 10

W3PV03 80 80 70 80 10

W3PV04 90 90 80 90

W3PV05 60 65 60 60 10

W3PV06 90 1 85 90 90 10

W3PV07 90 85 90 90 20

W3PV08 45 15 50 45 10 45

W3PV09 85 30 85 75 2 85 10

W3PV10 75 75 1 75 5 75 10

W3ST01 40 40 40 1, 0 40

W3ST02 95 90 80 75

W3ST03 75 1 75 70 65

W3ST04 75 1 75 75 75

W3ST05 80 1 75 80 1, 0 70

W3ST06 65 1 65 65 65

W3ST07 80 80 80 65

W3ST08 90 75 70 65

W3ST09 75 80 70 75

W3ST10 100 95 75 90

WCPVO1 90 90 75 10 85 10

WCPV02 75 75 75 10 75 10

WCPV03 93 90 65 90 30

WCPV04 60 1 60 60 50

WCPV05 95 95 90 10 95 10

WCPV06 90 90 80 90

WCPV07 90 35 90 90 40 85

WCPV08 90 10 80 75 20 70 15

WCPV09 85 70 65 85

WCPV10 85 85 80 15 85

WCST01 65 70 65 65

WCST02 75 70 75 60

WCST03 65 65 65 1, 0 65

WCST04 75 75 65 55

WCST05 90 60 65 30

WCST06 85 50 40 10

WCST07 75 75 75 75

WCST08 75 75 70 75

WCST09 65 65 65 65

WCST10 97 95 90 90

Plant ID

Site #3: 1640 m from well

Control Site: 5.3 miles N of well

Winter 2012 Winter 2013 Winter 2014 Winter 2015

BASELINE H&V H&V H&V H&V




The Desert Dry Wash Woodland Monitoring and Reporting Plan (Ironwood Consulting, Inc., 2011b)

includes this language about the efficacy and timing of ongoing implementation of this Study:

On an annual basis, the efficacy of this program will be evaluated. If monitoring is determined by

BLM, CDFG, and CPUC (for SCE components) to be ineffective (either because these trees are using

only surface water sources or other variables interfere with the surveys that make it impossible to

determine any cause-effect relationship), it may be stopped at that time. If these agencies determine

the need for additional monitoring, the study may be extended to an agreed upon time during post-

construction... After a period of three years post-construction, a final dry wash woodland monitoring

program report will be submitted to BLM, CDFG, and CPUC (for SCE components).

The results and discussion imply that this study so far has produced little data that clearly implicates

groundwater drawdown with tree stress or mortality. The study also does not support the concept of palo

verdes and smoke trees being obligate phreatophytes. It is suspected that these trees are most likely

facultative phreatophytes, which employ multiple strategies for acquiring and storing water in this harsh

desert environment (including a combination of surface and groundwater acquisition; shallow and deep

root systems; drought deciduousness; and location along deeper washes channels which consolidate

whatever flows come from infrequent storms).

Close to 3 years of data have been collected for these sites documenting generalized health and vigor, as

well as seasonal patterns of leafing and flowering. This represents close to 3 years of "Baseline Conditions"

for these study trees. All the trees are marked by accurate GPS coordinates and repeatable photographs,

and can be relocated and reevaluated at any time in the future.

As specified in the DDWP, this study is scheduled to continue for a period of three years post-construction

(i.e. post well production). As construction drew to a close on the solar farm in late 2014, production at

the well ceased, and all the trees are surviving.

Although there appear to be some losses of live tissue in some of the trees, it is impossible to correlate

these losses with well production, because the entire region has been under a prolonged drought

throughout the period.

Thus, it is recommended that this study be discontinued at this time.


5.0 INTEGRATED WEED MANAGEMENT

5.1 Overview The following represents a summary of activities associated with weed management that was completed

during 2015. Surveys for weeds were conducted in the following areas associated with the solar farm:

The inner perimeter of the Project where soil had been disturbed including the detention ponds

for monthly surveys

All areas of the solar farm that have been disturbed that are currently occupied by solar panels

and associated infrastructure as annual survey

The undisturbed 250-foot/76.5-meter buffer area around the site as a quarterly survey

The gen-tie right-of-way as a quarterly survey


A series of surveys for the presence of weeds in the solar farm and gen-tie line were completed to estimate

invasiveness of weeds. Table 5 details survey dates and locations in 2015.

A quarterly pedestrian survey of the 250 foot/76.25 meter buffer zone outside the tortoise fence of the

Solar Array portion of Project area was completed. In addition to the outer buffer area, monthly surveys

of disturbed and undeveloped areas along the inside perimeter of the site were completed. These

pedestrian surveys were conducted in the inner perimeter where soils had been disturbed and cleared. In

the first quarter of 2015, an annual survey of the solar farm array area was also completed. This survey

was completed using a pick-up truck. One biologist drove the truck and the other two biologists made

observations of weeds present in the array areas using binoculars.

Any weeds encountered would be recorded with a hand-held GPS unit and were hand-pulled, bagged and

disposed of in a trash dumpster.


Table 7. Summary of Weed Survey Dates and Locations, 2015


5.3.1 Solar Farm During the first quarter of 2015 surveys, Sahara mustard (Brassica tournefortii) was found as individual plants primarily in the southwestern portion of the solar farm (Figure 5). Salt cedar (Tamarix ramosissima) was found in two of the retention basins located on the southern border of the solar farm. During construction, the retention basins were noted as sources of these invasive weeds likely due to stormwater flooding events in the region. In addition, London rocket (Sisymbrium irio) and nettle-leaved goosefoot (Chenopodium murale) were found in scattered locations within the solar farm.

No invasive weeds were detected in the retention basins or around the solar farm site throughout the second and third quarter surveys.

During fourth quarter surveys, approximately 500 salt cedars were detected in retention basin 2-2 on the site. This is the same retention basin where salt cedars were found during the First Quarter, 2015 survey (Figure 1). All salt cedar were dug out, bagged and disposed of in the trash dumpster. One incidental salt cedar was observed in array block 3. This weed was also dug out, bagged and disposed of in a trash dumpster.

Dates

Inner

Perimeter

(Monthly)

250-ft/76.25-m

Buffer Area

(Quarterly)

Gen-Tie Line

(Quarterly)

Annual Survey of

Disturbed Area

(Solar Farm)

1/20/2015 X

2/17/2015 X

3/3/2015 x

3/3-3/8/2015 x x x

4/7/2015 x

5/8/2015 x

6/21-23/2015 x x x

7/9/2015 x

8/10/2015 x

9/10/2015 x

8/28/2015-

8/30/2015x x

10/9/2015 x

11/18/2015 x

12/8/2015 x

12/7-9/2015 x x

First Quarter

Second Quarter

Third Quarter

Fourth Quarter


5.3.2 Gen-Tie Line During the first quarter of 2015 surveys, Sahara mustard and London rocket were found in the gen-tie line from pole pads 1 to 31 along Kaiser Road (Figure 6). The number of weeds within any pole pad area was less than 100 indicating a limited degree of invasiveness. A few nettle-leaved goosefoot weeds was observed between pole pads 8 and 9, and again between pole pads 10 and 11. Sahara mustard and London rocket was again found in the gen-tie line from pole pads 56 through 69 also in a limited degree of invasiveness.

No invasive weeds were detected in the gen-tie corridor in the subsequent surveys for the remainder of the year.

5.3.3 Herbicide Use During December weed surveys, Ironwood biologists observed non-native and native vegetation onsite

that were dying and exhibiting signs of possible herbicide use.

Ironwood was not present during the herbicide application but communication from Next Era Energy

confirmed that pre- and post-emergent herbicides (SFM 75 and Garlon 4) were applied to solar arrays and

retention basins only within the solar farm where weed growth was present as noted by Next Era Energy

in Figure 7. The herbicide applicators were given WEAP training that included weed identification prior

to beginning work and used portable tanks with hand guns for pin point accuracy. Herbicide application

began on November 9th in the arrays and finished at the retention ponds on November 19th and 20th. No

herbicides were applied outside the solar farm (e-mail communication, Adam Dobrzanski).

Photo 11. Dead plants beneath solar arrays Photo 12. Dead plants in retention basins


Photo 13: Native rubber rabbit bush (Ericameria Photo 14: Native creosote (Larea tridentata)

nauseosa) affected by herbicide use affected by herbicide use

An approved Pesticide Use Proposal (PUP) is in effect for use of herbicides at Desert Sunlight (Bureau of

Land Management 2015) that also has an associated Environmental Assessment (EA).

The PUP specifies the application date for pre- and post-emergent herbicides for effectiveness; pre-

emergent herbicides that specifically target germinating seeds, is applied in early fall prior to fall/winter

rains and weed germination and post-emergent herbicides are applied to growing plants with secondary

leaves and is applied while the weed is actively growing, most effectively in early seedling stage. It has

been observed that plants are less likely to be actively growing due to approaching winter weather in

November, so perennial weeds present at the time of herbicide application may not likely to have been

actively growing, which may have limited the effectiveness of foliar application of a post-emergent

herbicide.

The PUP and associated EA both also specify that impacts to non-target plant species would be minimal.

Observations have shown that native plant species not on the target plant list have also been affected by

the herbicide application.




Figure 7. Herbicide Use Areas (in orange)


5.4 Conclusions and Recommendations

On the solar farm, salt cedar continues to be found in the southern retention basins, while London rocket and nettle-leaved goosefoot was found in scattered locations within the solar farm. On the gen-tie corridor, Sahara mustard, London rocket, and nettle-leaved goosefoot were detected, but the numbers indicated a limited degree of invasiveness. All invasive weeds detected were removed, bagged and disposed in a trash dumpster. Continued monitoring and eradication of weeds within the project area is recommended to prevent any increase in invasive weeds.

It is recommended that herbicide application, should it become necessary again, be applied as a pre-

emergent herbicide in early fall as it would be more effective in curtailing germinating weed seeds than

application of a post-emergent at the time of the year when most annual weeds have set seeds and died.

Impacts to native plants from herbicide application should also be minimal, as stated by the PUP and

associated EA. It is also recommended that impacts to native plants from the recent herbicide application

be quantified and documented in the Pesticide Application Records maintained by the applicator and

included in the next annual biological monitoring report to BLM.

6.0 RAVEN MANAGEMENT

6.1 Overview

This report summarizes the implementation of the Raven Management Plan (RMP) during the course of

project activities on the Desert Sunlight Solar Farm Project in 2015. Much of the RMP was implemented

during the construction phase of the project and is discussed in detail in previous annual reports. This

report will focus on implementation of the RMP during 2015 and comparing results collected in previous

years.

The purpose of the RMP is to address potential impacts to desert tortoise (Gopherus agassizii) by

eliminating and minimizing subsides made available to Common ravens (raven; Corvus corax) to the

maximum extent practicable. The purpose of this project-specific plan is to protect juvenile and hatchling

desert tortoises in the project vicinity (within the immediate area of the Chuckwalla Valley) from increased

predation by ravens by eliminating or minimizing raven attractants and resources (e.g., surface water,

trash and animal and plant waste materials; perching, nesting, and roosting sites) during construction,

operation and maintenance, and decommissioning of the project.


6.2.1 Incidental Sightings During the construction phase of the Project, raven(s) sighted by biological monitors were recorded on

standardized data forms during regular daily monitoring activities. Project construction concluded in


December of 2014, which included a drastic reduction in the amount of time biologists spent in and

around the project. There were, however, ravens caught on game cameras during the avian carcass

removal trials which took place 16 December 2014 through 21 January 2015 and 27 March 2015 through

18 May 2015.

6.2.2 Avian Point Count Surveys During construction and Operations and Maintenance, biologists repeated surveys at points within the

Solar Farm site and controls using the same methods employed during baseline surveys (Figure 2). The

purpose of conducting Avian Point Count (APC) surveys is to measure any potential increase or decrease

in the number of Ravens sighted on the Solar Farm project or adjacent to project components.

Avian Point Count Surveys were conducted by avian biologists who had extensive prior experience

surveying for birds in the eastern deserts of California. Biologists performing point counts had competent

bird identification skills and were able to detect species by sight and sound (calling and singing).

Survey periods were chosen to optimize the detection potential for seasonal migrants as well as resident

birds. Surveys were conducted during the time of the day when birds were most active, generally the first

four hours after sunrise.

Avian Point Count Surveys began during fall 2011 and were performed seasonally through mid-November

2015, excluding the summer months (June, July and August). Avian Point Count locations are depicted in

Figure 8.

6.2.3 Nest Surveys Driving surveys followed previously-utilized survey protocols in order to detect raven nests within one

mile of all project components. The ground beneath confirmed raven nests was inspected for desert

tortoise remains. The Project’s Designated Biologist (DB) had the authority to recommend nest or problem

raven removal through consultation with Land Managers and regulatory agencies including: Bureau of

Land Management (BLM), United States Fish and Wildlife Service (USFWS), and California Department of

Fish and Wildlife (CDFW).

Nest surveys may also be used to evaluate and assess population trends in ravens; and an increase in

nesting ravens over the course of Project development and operations could indicate an increase in

subsidy availability.


Figure 8. Avian Point Count locations associated with the Desert Sunlight Solar Farm



6.3.1 Incidental Sightings Incidental detections of ravens utilizing subsidies within the Solar Farm were recorded during all biological

activities during the Project’s construction phase. Biological monitors and surveyors recorded incidental

sightings of ravens utilizing project subsidies on standardized data sheets in order to assess the pressures

these birds are placing on project subsidies. The presence of ravens was documented on the Project site

prior to the initiation of construction activities. Construction monitors consistently reported ravens flying

during early morning hours from the west, heading east. The continuity of these reports suggested that

ravens regularly roost in Pinto Wash (east of the project site) and fly westward (toward the Colorado River

Aqueduct pump station and Eagle Mountain Mine), over the project site, in search of resources.

The number of incidental sightings recorded within the solar-farm footprint corresponded with

construction activities in the years 2011 through 2015. Instances where ravens were documented utilizing

project subsidies were responded to in the following ways:

Project personnel were reminded of the project’s refuse management requirements and all

project-related trash was confined to enclosures that provided proper containment.

Biological monitors attempted to remove (and make unavailable to ravens) all project-related

carrion, including road-killed animals and construction kills.

Efforts were made to contain water and make it unavailable to ravens.

Construction workers and subcontractors are required to address waste management on a daily

basis (i.e. trash sweeps, manage own waste).

Entrance gate guards check the back of open vehicles for trash as they enter the Project.

In the event that additional waste management is needed (i.e., high wind events, storm events),

crews are assembled as necessary to ensure trash is contained in accordance with the RMP.

Ravens were photographed on game cameras 52 times on 35 different carcasses in 2015. Similar to 2014

results, the greatest number of ravens in any single camera frame was two, suggesting that at least one

pair of ravens continues to frequent the Project site.


Photo 15. Common raven pulling apart project trash, while perched on solar panels

6.3.2 Avian Point Count Survey Results

Table 8 below compares five years of Avian Point Count data, with absolute numbers of individuals (Y-

axis) plotted over the course of each year. Data were grouped into seasons since the protocols indicate

that points must be visited once per season (rather than on a monthly basis). Grouping them this way,

thus provides a more accurate comparison over years. These graphs show seasonal trends related to

Raven abundance within the Project vicinity. The two highest counts occurred in fall of 2011 (150

ravens) and Winter of 2014 (153 ravens). Table 9 shows the same data as a continuous time line.


Table 8. Raven Detections during Avian Point Counts 2011-2015

Table 9. Total Number of Raven Detections at Point Counts over Time

0

20

40

60

80

100

120

140

160

180

Winter Spring Fall

Tota

l # R

aven

s D

etec

ted

Total # of Ravens Detected During Avian Point Counts by Year and Season

2012 2013 2014 2015 2011

0

20

40

60

80

100

120

140

160

180

Fall 2011 Winter11-12

Spring12

Fall 12 Winter12-13

Spring13

Fall 13 Winter13-14

Spring14

Fall 14 Winter14-15

Spring15

Fall 15

Total # of Ravens detected During Avian Point Counts Over Time


Program Distance was used to analyze the data from the point counts to determine an overall density

(Tables 10 and 11). Program Distance uses the distance measurements taken by the observer to estimate

a detection function for the species of interest. The detection of objects is a function of distance from the

observer. The Distance software uses the collected data to estimate that function and calculate a more

accurate estimate of density than raw counts alone.

Table 10. Raven Density Estimates by Season and Year

SEASON DENSITY ESTIMATE

LOWER CONFIDENCE

LIMIT

UPPER CONFIDENCE

LIMIT

DETECTION FUNCTION

GOODNESS OF FIT

FALL 2011 0.029 0.009 0.097 Hazard Rate key 0.9432

WINTER 11-12 Unable to estimate detection function

SPRING 2012 0.128 0.031 0.533 Hazard Rate key with 2 cosine adjustments

0.3761

FALL 2012 0.001 0.001 0.003 Uniform key with 2 cosine adjustments

0.3977

WINTER 12-13 0.003 0.002 0.005 Uniform key with 4 simple polynomial

adjustments

0.2953

SPRING 2013 0.024 0.008 0.067 Hazard Rate key with 2 cosine adjustments

0.4743

FALL 2013 0.005 0.002 0.012 Hazard Rate key 0.8095

WINTER 13-14 0.013 0.008 0.021 Negative Exponential with 2 hermite polynomial

adjustments

0.7745

SPRING 2014 0.004 0.002 0.011 Hazard Rate key 0.3660

FALL 2014 0.002 0.001 0.004 Uniform key with 2 cosine adjustments

0.7847

WINTER 14-15 0.003 0.001 0.008 Uniform key with 2 cosine adjustments

0.9838

SPRING 2015 0.001 0.001 0.003 Hazard Rate key with 1 cosine adjustment

0.9748

FALL 2015 0.015 0.008 0.027 Hazard Rate key with 1 cosine adjustment

0.6801


Table 11. Estimated Density of Common ravens at Desert Center over Time

0.029

0.128

0.001 0.003

0.024

0.005

0.013

0.004 0.002 0.003 0.001

0.015

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

0.11

0.12

0.13

0.14

Fall 11 Winter11-12

Spring12

Fall 12 Winter12-13

Spring13

Fall 13 Winter13-14

Spring14

Fall 14 Winter14-15

Spring15

Fall 15

Estimated Density of Common ravens Over Time

6.3.3 Nest Survey Results

Only 4 raven nests were observed during the 2015 breeding season (Table 12). All four nesting attempts

were successful with 8 fledglings produced for a success rate of 2 nestlings/nest.

Two of the active raven nests were within 2 miles of the project perimeter and the other two were > 6

miles from the project footprint (Figure 9).

During each year (2012-2015), biologists surveyed the ground surface below raven nests in search of

juvenile desert tortoise carcasses, which would indicate predation or scavenging by nest occupants.

Ground surface surveys below common raven nests for juvenile tortoises has resulted in no (0) desert

tortoise carcasses detected during any of these search efforts.

Table 12. Comparison of success, failure and total number of raven nests from 2013 through 2015

Note: 2012 data is not included because a specific nesting survey was not completed

6 7 4

4

1

0

0

2

4

6

8

10

12

2013 2014 2015

# o

f N

ests

Common raven Nest Success 2013-2015

Successful Failed


Figure 9. Raptor and Raven Nests Detected during 2015


6.4 Conclusion and Recommendations

The presence of ravens within the Project boundary fluctuated temporally due to natural causes, placing

dynamic pressures on Project subsidies over the course of the Project. Common ravens, including at least

one breeding pair, were documented in the Project area (within at least one mile of the solar farm

perimeter) prior to the onset of construction activities at the Desert Sunlight Solar Farm. Seasonal changes

to the abundance and distribution of common ravens within the Chuckwalla Valley was not well

understood until species-specific surveys were implemented as a requirement of this Project’s RMP.

Through project-specific survey efforts, biologists have learned that seasonal fluctuations in raven

numbers and distribution is a natural phenomenon. The pressure placed on Project subsidies fluctuates

as the abundance of ravens shifts temporally within the Project’s vicinity. Grubbing and vegetation

clearing activities during the construction phase unintentionally provided a temporary food subsidy to

ravens. Raven subsidy use was the highest when vegetation clearing activities in the construction phase

took place during the fall and winter months, corresponding with natural increases in raven numbers

throughout the Chuckwalla Valley. Since the completion of clearing and grubbing activities, there has been

a decrease in the benefit gained by ravens from Project subsidies.

Following completion of the construction phase, there were no more common raven nesting attempts

within close proximity (one-mile) of the project, than there were prior to the onset of Project-related

construction activities. No change to the number of ravens attempting to nest within proximity of the

Project indicates that whatever benefits were gained during the construction phase were temporary.

Additionally, the number of Ravens detected incidentally post-construction are equivalent to the number

detected pre-construction.

The primary goal of this project-specific RMP was to protect juvenile and hatchling desert tortoises in the

Project vicinity (within the immediate area of the Chuckwalla Valley) from increased predation by ravens

by eliminating or minimizing raven attractants and resources (e.g., surface water, trash and animal and

plant waste materials; perching, nesting, and roosting sites) during construction, operation and

maintenance, and decommissioning of the project. During the construction phase and during operations

and maintenance, Common raven nests have been routinely monitored for the presence of desert tortoise

remains, which would indicate predation or scavenging by ravens. To date, no desert tortoise remains

have been found associated with ravens or raven nests within proximity to the Desert Sunlight Solar Farm.

During the construction and subsequent operations and maintenance of this Project, the goals of the

Raven Management Plan have been met through successful implementation of the prescribed measures

that it required. Adaptive management and the continued assessment of applied mitigation measures

resulted in effective action. Monitoring strategies were able to successfully assess the long-term trends

in raven populations and evaluate the pressures that ravens placed on Project subsidies while

determining impacts to desert tortoise populations in the vicinity.

Ironwood Consulting, Inc. Office: 1030 Nevada Street, Suite 201, Redlands, CA 92374 Mail: PO Box 10068, San Bernardino, CA 92423

Phone: (909) 798-0330 Fax: (909)798-0330 www.ironwoodbio.com

REFERENCES

Bureau of Land Management 2011 Desert Sunlight Solar Farm Final Environmental Impact Statement and Record of Decision.

2015 Pesticide Use Proposal Number 0015-CA-060-002, Desert Sunlight Solar Project.

Environmental Assessment Number DOI-BLM-060-0015-0017-EA

Dobrzanski, Adam

2015 Email Communication between Mr. Adam Dobrzanski and Ms. Lehong Chow/Ms. Kathy

Simon. December 21, 2015.

Ironwood Consulting, Inc.

2011a Avian and Bat Protection Plan for the Desert Sunlight Solar Farm Project. Report prepared for Desert Sunlight Holdings, LLC, Oakland, California.

2011b Desert Dry Wash Woodland Monitoring and Reporting Plan, First Solar Desert Sunlight Solar Project, Riverside County. BLM Case File Number CACA-48649. July 2011

2011c Vegetation Salvage Plan, Desert Sunlight Solar Farm. BLM Case File Number CACA-48648. Riverside County, CA. Revised 5 October 2011.

2011d Integrated Weed Management Plan, Desert Sunlight Solar Farm. BLM Case File Number CACA-48648. Riverside County, CA. Revised 17 June 2011.

2012 Annual Report for Biological Resources Monitoring, First Solar Desert Sunlight Solar Project, Riverside County. BLM Case File Number CACA-48649. Biological Opinion # FWS-ERIV-0880789-11F0041, 1 January - 31 December 2012.

2013 2012 Annual Report for Desert Sunlight Solar Farm. Report prepared for Desert Sunlight Holdings. LLC, Oakland, California.

2014 2013 Annual Report for Biological Resource Monitoring. First Solar Desert Sunlight Solar Project, Riverside County. BLM Case File Number CACA-48649. Report prepared for Desert Sunlight Holdings. LLC, Oakland, California.

2015 2014 Annual Report for Desert Sunlight Solar Farm. First Solar Desert Sunlight Solar Project, Riverside County. BLM Case File Number CACA-48649. Report prepared for Desert Sunlight Holdings. LLC, Oakland, California.

Ralph, C. John; Sauer, John R.; Droege, Sam, technical editors

1995. Monitoring Bird Populations by Point Counts. Gen. Tech. Rep. PSW-GTR-149. Albany, CA: Pacific Southwest Research Station, Forest Service, US. Department of Agriculture; 187 p.

Documents

2015 Annual Report for Biological Resources Monitoring€¦ · 2015 Annual Report for Biological Resources Monitoring Desert Sunlight Solar Project, Riverside County BLM CASE FILE