HomeMy WebLinkAboutF&G - Notice of Findings-Coast Yellow Leptosiphon, Lassics Lupine, and Tricolored Blackbird Commissioners STATE OF CALIFORNIA Valerie Termini,Executive Director
Eric Sklar,-President Edmund G.Brown Jr.,Governor P.O.Box 944209
Saint Helena Sacramento,CA 94244-2J TE COUNTY
Anthony C.Williams,Vice President (916)653-4899 ADMINISTRATION
Huntington Beach Fish and Game Commission fgc@fgc.ca.gov
Jacque Hostler-Carrnesin,Member www.fgc.ca.gov SEP 12 2018
McKinleyville
Russell E.Burns,Member _, r
r ,- OROVILLE,CALIFORNIA
Napa � ..�> ,.�a p
Peter S.Silva,Member
Jamulice'
.OF C.11.4
Wildlife Heritage and Conservation
Since 1870
September 12, 2018
TO ALL INTERESTED AND AFFECTED PARTIES:
This is to provide you with Notice of Findings regarding the petitions to list coast yellow
leptosiphon, Lassies lupine and tricolored blackbird as endangered/threatened under
the California Endangered Species Act. The notices will be published in the California
Regulatory Notice Register on September 14, 2018.
Sincerely,
heti Tiemann
Associate Governmental Program Analyst
Attachments
•
•
California Natural Resources Building
1416 Ninth Street, Room 1320,Sacramento,California 95814
BUTTE COUNTY
ADMINISTRATION
NOTICE OF FINDINGS SEP 21
8
OROVILLE,CALIFORNIA
Lassics lupine
(Lupinus constancei)
NOTICE IS HEREBY GIVEN that the California Fish and Game Commission
(Commission), at a meeting in Ventura, California on April 19, 2018, found pursuant to
Fish and Game Code Section 2075.5, that the information contained in the petition to
list Lassics lupine (Lupinus constance;) and other information in the record before the
Commission, warrants adding the Lassics lupine to the list of endangered species under
the California Endangered Species Act (CESA) (Fish & G. Code, § 2050 et seq.). (See
also Cal. Code Regs., tit. 14, § 670.1, subd. (i).)
NOTICE IS ALSO GIVEN that, at its August 23, 2018 meeting in Fortuna California, the
Commission adopted the following findings outlining the reasons for its determination.
I. Background and Procedural History
Petition History
On July 19, 2016, the Commission received a petition (Petition) from Mr. Dave Imper
and Ms. Cynthia Elkins from the Center for Biological Diversity to list Lassics lupine as
an endangered species pursuant to CESA (Fish & G. Code, § 2050 et seq.).
On July 29, 2016, the Commission referred the Petition to the Department for
evaluation.
On August 12, 2016, as required by Fish and Game Code Section 2073.3, the
Commission published notice of receipt of the Petition in the California Regulatory
Notice Register. (Cal. Reg. Notice Register 2016, No. 33-Z, p. 1463). The Department
on September 14, 2016, pursuant to Fish and Game Code Section 2073.5, requested a
30-day extension of time to complete its evaluation report. The Commission approved
the extension at its October 20, 2016 meeting in Eureka, California.
On December 8, 2016, the Department provided the Commission with a report,
"Evaluation of the Petition from Mr. David lmper and Ms. Cynthia Elkins to List Lassics
Lupine (Lupinus constance!) as an Endangered Species under the California
Endangered Species Act" (Evaluation). Based upon the information contained in the
Petition, the Department concluded, pursuant to Fish and Game Code, Section 2073.5,
subdivision (a), that sufficient information exists to indicate that the petitioned action
may be warranted, and recommended to the Commission that the Petition should be
accepted and considered.
Page 1 of 7
On February 8, 2017, at its scheduled public meeting in Rohnert Park, California, the
Commission considered the Petition, the Department's Evaluation and
recommendation, and comments received. The Commission found that sufficient
information existed to indicate the petitioned action may be warranted and accepted the
Petition for consideration.
Subsequently, on February 24, 2017, the Commission published its Notice of Findings
for Lassies lupine in the California Regulatory Notice Register, designating Lassies
lupine as a candidate species (Cal. Reg. Notice Register 2017, No. 8-Z, p. 258).
Department Review
The Commission's action designating the Lassies lupine as a candidate species
triggered the Department's process for conducting a status review to inform the
Commission's decision on whether to list the species. The Commission received the
Department's status review report at its February 7-8, 2018 meeting in Sacramento,
California. On April 19, 2018, in Ventura, California, the Commission found that the
information contained in the petition and the other information in the record before the
Commission warrants listing Lassies lupine as an endangered species under the
California Endangered Species Act.
Species Description
Lassies lupine is an herbaceous perennial plant of the legume family (Fabaceae) that
was described as a new species in 1983. Lassies lupine is only found near the summits
of remote mountains in northern California called the Lassies, which have unique
serpentine-influenced soils. The Lassics are located in Humboldt and Trinity counties
within the Six Rivers National Forest. There are two known populations of Lassies
lupine, occupying a combined area of approximately 1.6 hectares (4 acres). The smaller
of the two Lassies lupine populations is found on a southwest-facing slope of a
mountain called Red Lassie. The larger Lassies lupine population is located entirely
within Mt. Lassie Wilderness on adjoining peaks of Mt. Lassie.
II. STATUTORY AND LEGAL FRAMEWORK
The Commission, as established by the California Constitution, has exclusive statutory
authority under California law to designate endangered, threatened, and candidate
species under CESA. (Cal. Const., art. IV, § 20, subd. (b); Fish & G. Code, § 2070.) The
CESA listing process for Lassies lupine began in the present case with the Petitioners'
submittal of the Petition to the Commission on July 19, 2016. The regulatory and legal
process that ensued is described in some detail in the preceding section above, along
with related references to the Fish and Game Code and controlling regulation. The
CESA listing process generally is also described in some detail in published appellate
case law in California, including:
Page 2 of 7
• Mountain Lion Foundation v. California Fish and Game Commission (1997) 16
Ca1.4th 105, 114-116;
• California Forestry Association v. California Fish and Game Commission (2007)
156 Cal.App.4th 1535, 1541-1542;
• Center for Biological Diversity v. California Fish and Game Commission (2008)
166 Cal.App.4th 597, 600; and
• Natural Resources Defense Council v. California Fish and Game Commission
(1994) 28 Cal.App.4th 1104, 1111-1116.
The "is warranted" determination at issue here for Lassics lupine sterns from
Commission obligations established by Fish and Game Code Section 2075.5. Under
this provision, the Commission is required to make one of two findings for a candidate
species at the end of the CESA listing process; namely, whether the petitioned action is
warranted or is not warranted. Here, with respect to the Lassics lupine, the Commission
made the finding under Section 2075.5(e)(2) that the petitioned action is warranted.
The Commission was guided in making these determinations by statutory provisions
and other controlling law. The Fish and Game Code, for example, defines an
endangered species under CESA as "a native species or subspecies of a bird, mammal,
fish, amphibian, reptile or plant which is in serious danger of becoming extinct
throughout all, or a significant portion, of its range due to one or more causes, including
loss of habitat, change in habitat, over exploitation, predation, competition, or disease."
(Fish & G. Code, § 2062.) Similarly, the Fish and Game Code defines a threatened
species under CESA as "a native species or subspecies of a bird, mammal, fish,
amphibian, reptile or plant that, although not presently threatened with extinction, is
likely to become an endangered species in the foreseeable future in the absence of the
special protection and management efforts required by this chapter." (Id., § 2067.)
The Commission also considered Title 14, Section 670.1, subdivision (i)(1)(A), of the
California Code of Regulations in making its determination regarding Lassics lupine.
This provision provides, in pertinent part, that a species shall be listed as endangered or
threatened under CESA if the Commission determines that the species' continued
existence is in serious danger or is threatened by any one or any combination of the
following factors:
1. Present or threatened modification or destruction of its habitat;
2. Overexploitation;
3. Predation;
4. Competition;
Page 3 of 7
5. Disease; or
6. Other natural occurrences or human-related activities.
Fish and Game Code Section 2070 provides similar guidance. This section provides
that the Commission shall add or remove species from the list of endangered and
threatened species under CESA only upon receipt of sufficient scientific information that
the action is warranted. Similarly, CESA provides policy direction not specific to the
Commission per se, indicating that all state agencies, boards, and commissions shall
seek to conserve endangered and threatened species and shall utilize their authority in
furtherance of the purposes of CESA. (Fish & G. Code, § 2055.) This policy direction
does not compel a particular determination by the Commission in the CESA listing
context. Nevertheless, "'[I]aws providing for the conservation of natural resources` such
as the CESA 'are of great remedial and public importance and thus should be construed
liberally." (California Forestry Association v. California Fish and Game Commission,
supra, 156 Cal. App.4th at pp. 1545-1546, citing San Bernardino Valley Audubon
Society v. City of Moreno Valley(1996) 44 Cal.App.4th 593, 601; Fish & G. Code,
§§ 2051, 2052.)
Finally in considering these factors, CESA and controlling regulations require the
Commission to actively seek and consider related input from the public and any
interested party. (See, e.g., Id., §§ 2071, 2074.4, 2078; Cal. Code Regs., tit. 14,
§ 670.1, subd. (h).) The related notice obligations and public hearing opportunities
before the Commission are also considerable. (Fish & G. Code, §§ 2073.3, 2074,
2074.2, 2075, 2075.5, 2078; Cal. Code Regs., tit. 14, § 670.1, subds. (c), (e), (g), (i);
see also Gov. Code, § 11120 et seq.) All of these obligations are in addition to the
requirements prescribed for the Department in the CESA listing process, including an
initial evaluation of the petition and a related recommendation regarding candidacy, and
a review of the candidate species' status culminating with a report and recommendation
to the Commission as to whether listing is warranted based on the best available
science. (Fish & G. Code, §§ 2073.4, 2073.5, 2074.4, 2074.6; Cal. Code Regs., tit. 14,
§ 670.1, subds. (d), (f), (h).)
Ill. Factual and Scientific Bases for the Commission's Final Determination
The factual and scientific bases for the Commission's determination that designating the
Lassics lupine as an endangered species under CESA is warranted are set forth in
detail in the Commission's record of proceedings including the Petition, the
Department's Petition Evaluation Report, the Department's status review, written and
oral comments received from members of the public, the regulated community, tribal
entities, the scientific community and other evidence included in the Commission's
record of proceedings.
Page 4 of 7
The Commission determines that the continued existence of the Lassics lupine in the
State of California is in serious danger or threatened by one or a combination of the
following factors as required by the California Code of Regulations Title 14,
Section 670.1, subdivision (i)(1)(A):
1. Present or threatened modification or destruction of its habitat;
2. Overexploitation;
3. Predation;
4. Competition;
5. Disease; or
6. Other natural occurrences or human-related activities.
The Commission also determines that the information in the Commission's record
constitutes the best scientific information available and establishes that designating the
Lassics lupine as an endangered species under CESA is warranted. Similarly, the
Commission determines that the Lassics lupine is in serious danger of becoming extinct
throughout all, or a significant portion, of its range due to one or more causes, including
loss of habitat, change in habitat, overexploitation, predation, competition, or disease.
The items highlighted here and detailed in the following section represent only a portion
of the complex issues aired and considered by the Commission during the CESA listing
process for the Lassics lupine. Similarly, the issues addressed in these findings
represent some, but not all of the evidence, issues, and considerations affecting the
Commission's final determination. Other issues aired before and considered by the
Commission are addressed in detail in the record before the Commission, which record
is incorporated herein by reference.
Background
The Commission bases its "is warranted" finding for the Lassics lupine most
fundamentally on the rarity of the Lassics lupine in combination with the immediate
impact of predation and the long-term impact of climate change.
Threats
Present or Threatened Modification or Destruction of Habitat
Lassics lupine habitat is threatened by climate change and, has been impacted by the
2015 Lassics Fire (particularly at the Red Lassic Population). The Mt. Lassie Population
is subject to ongoing habitat degradation and loss from forest encroachment. Lassics
• lupine faces a particularly severe threat from climate change because as the climate
system warms, potentially suitable habitat is expected to shift upwards in elevation, and
suitable habitat for Lassics lupine is expected to disappear. Many trees in the vicinity of
Page 5 of 7
•
the Red Lassic Population were killed by the 2015 Lassics Fire, including some of the
large trees that provide canopy shading for the Red Lassic Population during hot
summer afternoons. These trees, and the shade that they provide, appear to be critical
for the Lassics lupine habitat at the Red Lassic Population. The aftermath of the 2015
Lassics Fire is therefore a serious threat to the continued existence of the Red Lassic
Population. Aerial imagery clearly shows that the forest has become denser and has
encroached into Lassics lupine habitat on Mt. Lassic since the 1930s, a likely result of
historical fire suppression activities. Forest is less suitable for Lassics lupine survival and
reproduction than the treeless upper terrace and north slope ecological settings.
Approximately 0.8 to 1.2 hectares (2 to 3 acres) of habitat with soil that is suitable for
Lassics lupine at the Mt. Lassic Population has been encroached upon by forest, and
forest encroachment is expected to continue into Lassics lupine habitat in the future. The
Department considers degradation and loss of habitat to be a significant threat to the
continued existence of Lassics lupine.
Predation
Pre-dispersal seed predation by rodents has the potential to drive Lassics lupine to
extinction, and post-dispersal seed predation and herbivory are also significant threats
to the species. Deer mice, chipmunks, and California ground squirrels are the most
abundant seed predators near Lassic lupine populations, and are responsible for most
of the seed predation impacts on Lassics lupine. Lassics lupine plants closer to
vegetation, particularly chaparral vegetation, appear to be at greatest risk from seed
predation, and therefore encroaching vegetation is an important contributing factor to
seed predation. The Department considers predation to be a significant threat to the
continued existence of Lassics lupine.
Competition
Jeffrey pine and incense cedar forest trees, saplings, and seedlings compete with
Lassics lupine for light and moisture, particularly in the encroaching forest on the north
slope of Mt. Lassic. The Department considers competition with encroaching trees to be
a significant threat to the continued existence of Lassics lupine.
Other Natural Occurrences or Human-related Activities
The climate of California is certain to change due to warming of the global climate
system. Climate change scenarios for northern California in the vicinity of the Lassics
generally include similar annual precipitation levels, higher temperatures, and less snow
pack. Lassics lupine is sensitive to climate extremes, and mortality appears to be
highest when summer rainfall is low and summer temperatures are high, with these
effects exacerbated by early snowmelt. Furthermore, as the climate system warms,
potentially suitable habitat for mountaintop species such as Lassics lupine is expected
to shift upwards in elevation, and suitable habitat may be reduced or disappear. Climate
change is therefore expected to increase Lassics lupine mortality, and reduce or
Page 6 of 7
eliminate the amount of habitat that is suitable for the species.
Lassics lupine is also a narrowly distributed plant with only two populations and very low
numbers of individuals (approximately 454 adult plants during 2017 monitoring). Lassics
lupine's rarity and extremely limited distribution make the species very vulnerable to
stochastic (chance) events such as landslide, drought or fire, and to all other threats.
The loss of all or a significant
portion of either Lassics lupine population would represent the loss of a significant
portion of Lassics lupine's total range.
The 2015 Lassics Fire killed many trees in the vicinity of the Red Lassic Population,
including trees that provide canopy shading that is critical for the suitability of the habitat
at this location for Lassics lupine. While these trees are still standing, they are leafless
and at greater risk of falling over. The aftermath of the 2015 Lassics Fire is a threat to
the ability of the Red Lassic Population of Lassics lupine to survive and reproduce.
IV. FINAL DETERMINATION BY THE COMMISSION
The Commission has weighed and evaluated the information for and against
designating the Lassics lupine as an endangered species under CESA. This information
includes scientific and other general evidence in the Petition; the Department's Petition
Evaluation Report; the Department's status review; the Department's related
recommendations; written and oral comments received from members of the public, the
regulated community, various public agencies, and the scientific community; and other
evidence included in the Commission's record of proceedings.
Based upon the evidence in the record the Commission has determined that the best
scientific information available indicates that the continued existence of the Lassics
lupine is in serious danger or threatened by present or threatened modifications or
destruction of the species' habitat, predation, competition, disease, or other natural
occurrences or human-related activities, where such factors are considered individually
or in combination. (See generally Cal. Code Regs., tit. 14, § 670.1, subd. (i)(1)(A); Fish
& G. Code, §§ 2062, 2067.) The Commission determines that there is sufficient
scientific information to indicate that designating the Lassics lupine as an endangered
species under CESA is warranted at this time and that with adoption and publication of
these findings the Lassics lupine for purposes of its legal status under CESA and further
proceedings under the California Administrative Procedure Act, shall be listed as
endangered.
Page 7 of 7
BUTTE COUNTY
ADMINISTRATION
California Fish and Game Commission SEP 1 2 2018
NOTICE OF FINDINGS OROVILLE,CALIFORNIA
Coast Yellow Leptosiphon
(Leptosiphon croceus)
NOTICE IS HEREBY GIVEN that the California Fish and Game Commission (Commission), at
a meeting in Ventura, California on April 19, 2018, found pursuant to Fish and Game Code
Section 2075.5, that the information contained in the petition to list coast yellow leptosiphon
(Leptosiphon croceus) and other information in the record before the Commission, warrants
adding coast yellow leptosiphon to the list of endangered species under the California
Endangered Species Act (CESA) (Fish & G. Code, § 2050 et seq.). (See also Cal. Code
Regs., tit. 14, § 670.1, subs. (i).)
NOTICE IS ALSO GIVEN that, at its August 23, 2018 meeting in Fortuna, California, the
Commission adopted the following findings outlining the reasons for its determination.
I. Background and Procedural History
Petition History
On May 25, 2016, the Commission received a petition (Petition) from Ms. Toni Corelli, co-
sponsored by the California Native Plant Society (CNPS), to list coast yellow leptosiphon as an
endangered species pursuant to CESA (Fish & G. Code, § 2050 et seq.).
On May 27, 2016, the Commission referred the Petition to the California Department of Fish
and Wildlife (Department)for evaluation.
On June 10, 2016, as required by Fish and Game Code Section 2073.3, the Commission
published notice of receipt of the Petition in the California Regulatory Notice Register (Cal.
Reg. Notice Register 2016, No. 24-Z, p.1002). The Department on July 25, 2016, pursuant to
Fish and Game Code Section 2073.5, requested a 30-day extension of time to complete its
evaluation report. The Commission approved the extension at its August 24-25, 2016 meeting
in Folsom, California.
On September 26, 2016, the Department provided the Commission with a report, "Evaluation
of the Petition from Ms. Toni Corelli and the California Native Plant Society to List Coast
Yellow Leptosiphon (Leptosiphon croceus) as an Endangered Species under the California
Endangered Species Act" (Evaluation). Based upon the information contained in the Petition,
the Department concluded, pursuant to Fish and Game Code, Section 2073.5, subsection (a),
that sufficient information exists to indicate that the petitioned action may be warranted, and
recommended to the Commission that the Petition should be accepted and considered.
On December 8, 2016, at its scheduled public meeting in San Diego, California, the
Commission considered the Petition, the Department's Evaluation and recommendation, and
comments received. The Commission found that sufficient information existed to indicate the
petitioned action may be warranted and accepted the Petition for consideration.
1
Subsequently, on December 23, 2016, the Commission published its Notice of Findings for
coast yellow leptosiphon in the California Regulatory Notice Register, designating coast yellow
leptosiphon as a candidate species (Cal. Reg. Notice Register 2016, No. 52-Z, p. 2197).
Department Review
The Commission's action designating coast yellow leptosiphon as a candidate species
triggered the Department's process for conducting a status review to inform the Commission's
decision on whether to list the species. The Commission received the Department's status
review report at its February 7-8, 2018 meeting in Sacramento, California. On April 19, 2018, in
Ventura, California, the Commission found that the information contained in the petition and
the other information in the record before the Commission warrants listing coast yellow
leptosiphon as an endangered species under the CESA.
Species Description
Coast yellow leptosiphon is a low-growing annual plant in the Phlox family (Polemoniaceae)
that was first described in 1904. It is known from only one small population that occupies
approximately 167 square meters (1,800 square feet), located on Vallemar Bluff in Moss
Beach, San Mateo County, California. This population is located in coastal prairie habitat atop
a sea bluff at the edge of the coastline.
II. Statutory and Legal Framework
The Commission, as established by the California Constitution, has exclusive statutory
authority under California law to designate endangered, threatened, and candidate species
under CESA. (Cal. Const., art. IV, § 20, subd. (b); Fish & G. Code, § 2070.) The CESA listing
process for coast yellow leptosiphon began in the present case with the Petitioners' submittal
of the Petition to the Commission on May 25, 2016. The regulatory and legal process that
ensued is described in some detail in the preceding section above, along with related
references to the Fish and Game Code and controlling regulation. The CESA listing process
generally is also described in some detail in published appellate case law in California,
including:
• Mountain Lion Foundation v. California Fish and Game Commission (1997) 16 Cal.4th
105, 114-116;
• California Forestry Association v. California Fish and Game Commission (2007) 156
Cal.App.4th 1535, 1541-1542;
• Center for Biological Diversity v. California Fish and Game Commission (2008) 166
Cal.App.4th 597, 600; and
• Natural Resources Defense Council v. California Fish and Game Commission (1994) 28
Cal.App.4th 1104, 1111-1116.
The "is warranted" determination at issue here for coast yellow leptosiphon stems from
Commission obligations established by Fish and Game Code Section 2075.5. Under this
provision, the Commission is required to make one of two findings for a candidate species at
the end of the CESA listing process; namely, whether the petitioned action is warranted or is
2
not warranted. Here, with respect to coast yellow leptosiphon, the Commission made the
finding under Section 2075.5(e)(2) that the petitioned action is warranted.
The Commission was guided in making its determinations by statutory provisions and other
controlling law. The Fish and Game Code, for example, defines an endangered species under
CESA as "a native species or subspecies of a bird, mammal, fish, amphibian, reptile or plant
which is in serious danger of becoming extinct throughout all, or a significant portion, of its
range due to one or more causes, including loss of habitat, change in habitat, over exploitation,
predation, competition, or disease." (Fish & G. Code, § 2062.) Similarly, the Fish and Game
Code defines a threatened species under CESA as "a native species or subspecies of a bird,
mammal, fish, amphibian, reptile or plant that, although not presently threatened with
extinction, is likely to become an endangered species in the foreseeable future in the absence
of the special protection and management efforts required by this chapter." (Id., § 2067.)
The Commission also considered Title 14, Section 670.1, subsection (i)(1)(A), of the California
Code of Regulations in making its determination regarding coast yellow leptosiphon. The
provision provides, in pertinent part, that a species shall be listed as endangered or threatened
under CESA if the Commission determines that the species' continued existence is in serious
danger or is threatened by any one or any combination of the following factors:
1. Present or threatened modification or destruction of its habitat,
2. Overexploitation,
3. Predation,
4. Competition,
5. Disease, or
6. Other natural occurrences or human-related activities.
Fish and Game Code Section 2070 provides similar guidance. The section provides that the
Commission shall add or remove species from the list of endangered and threatened species
under CESA only upon receipt of sufficient scientific information that the action is warranted.
Similarly, CESA provides policy direction not specific to the Commission per se, indicating that
all state agencies, boards, and commissions shall seek to conserve endangered and
threatened species and shall utilize their authority in furtherance of the purposes of CESA.
(Fish & G. Code, § 2055.) This policy direction does not compel a particular determination by
the Commission in the CESA listing context. Nevertheless, "'Maws providing for the
conservation of natural resources' such as the CESA 'are of great remedial and public
importance and thus should be construed liberally." (California Forestry Association v.
California Fish and Game Commission, supra, 156 Cal. App.4th at pp. 1545-1546, citing San
Bernardino Valley Audubon Society v. City of Moreno Valley(1996) 44 Cal.App.4th 593, 601;
Fish & G. Code, §§ 2051, 2052.)
Finally in considering these factors, CESA and controlling regulations require the Commission
to actively seek and consider related input from the public and any interested party (see, e.g.,
Id., §§ 2071, 2074.4, 2078; Cal. Code Regs., tit. 14, § 670.1, subs. (h).). The related notice
obligations and public hearing opportunities before the Commission are also considerable
(Fish & G. Code, §§ 2073.3, 2074, 2074.2, 2075, 2075.5, 2078; Cal. Code Regs., tit. 14,
§ 670.1, subs. (c), (e), (g), (i); see also Gov. Code, § 11120 et seq.). All of these obligations
3
are in addition to the requirements prescribed for the Department in the CESA listing process,
including an initial evaluation of the petition and a related recommendation regarding
candidacy, and a review of the candidate species' status culminating with a report and
recommendation to the Commission as to whether listing is warranted based on the best
available science (Fish & G. Code, §§ 2073.4, 2073.5, 2074.4, 2074.6; Cal. Code Regs., tit.
14, § 670.1, subs. (d), (f), (h).).
Ill. Factual and Scientific Bases for the Commission's Final Determination
The factual and scientific bases for the Commission's determination that designating coast
yellow leptosiphon as an endangered species under CESA is warranted are set forth in detail
in the Commission's record of proceedings including the Petition, the Department's Evaluation;
the Department's status review; written and oral comments received from members of the
public, the regulated community, tribal entities, and the scientific community; and other
evidence included in the Commission's record of proceedings.
The Commission determines that the continued existence of coast yellow leptosiphon in the
state of California is in serious danger or threatened by one or a combination of the following
factors as required by the California Code of Regulations, Title 14, Section 670.1, subsection
(i)(1)(A):
1. Present or threatened modification or destruction of its habitat,
2. Overexploitation,
3. Predation,
4. Competition,
5. Disease, or
6. Other natural occurrences or human-related activities.
The Commission also determines that the information in the Commission's record constitutes
the best scientific information available and establishes that designating the coast yellow
leptosiphon as an endangered species under CESA is warranted. Similarly, the Commission
determines that coast yellow leptosiphon is in serious danger of becoming extinct throughout
all, or a significant portion, of its range due to one or more causes, including loss of habitat,
change in habitat, overexploitation, predation, competition, or disease.
The items highlighted here and detailed in the threats section represent only a portion of the
complex issues aired and considered by the Commission during the CESA listing process for
coast yellow leptosiphon. Similarly, the issues addressed in these findings represent some, but
not all of the evidence, issues, and considerations affecting the Commission's final
determination. Other issues aired before and considered by the Commission are addressed in
detail in the record before the Commission, which record is incorporated herein by reference.
Background
The Commission bases its "is warranted" finding for coast yellow leptosiphon most
fundamentally on the rarity of coast yellow leptosiphon in combination with the threats
identified in the next section.
4
Threats
Present or Threatened Modification or Destruction of Habitat
Habitat loss is considered the primary cause for species extinctions at local, regional, and
global scales (Dirzo and Raven 2003). Most of the coastal prairie habitat, which provides
potential habitat for coast yellow leptosiphon, has been destroyed or modified due to urban
development, agriculture, and invasion of non-native plant species (Ford and Hayes 2007).
Coast yellow leptosiphon was likely present over a larger geographic area prior to the
development of the San Mateo coast and conversion of coastal prairie habitat. Most of the
habitat surrounding the coast yellow leptosiphon population has been eliminated or altered due
to road construction, residential development, and invasion by non-native plant species,
particularly the invasive freeway iceplant which covers the coastal bluff adjacent to the coast
yellow leptosiphon population (Departmental observation). Installation of hardscape and storm
drainage systems related to urban development have altered runoff patterns and hydrology in
and around occupied coast yellow leptosiphon habitat. Although it is likely that coast yellow
leptosiphon has always been rare and restricted in range, past modification and destruction of
habitat has contributed to the limited availability of suitable habitat for this species. These past
changes affect the ability of coast yellow leptosiphon to survive and reproduce.
Development or changes in land use could directly destroy plants and living seeds in the seed
bank and destroy both occupied and potential habitat. Threats to coast yellow leptosiphon may
occur from development and changes in land use near the existing population. A residential
development project is proposed on the parcels immediately adjacent to the coast yellow
leptosiphon population (County of San Mateo 2017; Midcoast Community Council 2017). The
area proposed for development consists of seven lots, which will be consolidated into four lots
for the project. The proposed project will build four, three-story single-family residences,
between 4,740 and 4,859 square feet in size, and is pending design review approval by the
San Mateo County Coastside Design Review Committee (CDRC 2017).
Coast yellow leptosiphon has been buffered from impacts from the adjacent highway by the
1.0-hectare (2.5-acre) undeveloped coastal prairie that provides a natural buffer between
Highway 1 and the coast yellow leptosiphon population. Habitat buffers provide protection from
edge effects (Saunders et al. 1991; Given 1994), which are changes in community structure
that occur at the boundary of two habitats. Habitat buffers also provide extra protection from
human activities, allow for a more natural habitat boundary, slow the speed of water runoff,
and filter sediments, fertilizers, pesticides, heavy metals, and pathogens from runoff(Given
1994;Godfrey 2015; USDA 2017).
Any change in land use on this adjacent property is expected to result in indirect impacts to the
coast yellow leptosiphon population. The proposed development will alter the hydrologic
regime of the site. This will involve increased, altered, and unseasonal runoff patterns resulting
from addition of hard, impervious surfaces, installation of drainage features such as storm
drains and drainage pipes (Mesiti-Miller Engineering, Inc. 2017), and installation and use of
landscape irrigation systems. Development often leads to unseasonal summer moisture
resulting from watering landscape plants, washing cars, and other human activities. In addition,
residential development will lead to an increase in use of fertilizers and nutrients, herbicides,
pesticides, and other household chemicals and products which will run off and disperse into
habitat occupied by coast yellow leptosiphon and could impact the plants as well as alter the
5
soil chemistry. Increased nutrient load and unseasonal moisture resulting from human
activities creates conditions that promote the spread of non-native plant species, which can
outcompete the native plants for light, space, nutrients, water and other factors (Smil 1997;
Vitousek et al.1997; Line and White 2007). Furthermore, development will increase the number
of human visitors using the area, result in soil disturbance and compaction, increase garbage
and pollution, and create conditions that are favorable for the spread of non-native plant
species.
Construction of houses on the parcels adjacent to the coast yellow leptosiphon population will
lead to an increase in human use of the area. Walking paths exist on the bluff, and one heavily
used path exists immediately adjacent to the coast yellow leptosiphon population. Increased
human use of the area will increase the impacts to the habitat from foot traffic, will increase the
spread of weed seeds and introduce nutrients from dog walking, and will increase the risk of
trampling and killing of coast yellow leptosiphon plants. In addition, development of the area
will modify the aesthetics and accessibility of the bluff, potentially resulting in alterations of
walking patterns in the area. People may create new paths through the remaining portions of
the habitat accessible on Vallemar Bluff, potentially through the coast yellow leptosiphon
population.
Predation
The introduction of non-native slugs into the area from neighboring residential landscapes
could pose a threat to the coast yellow leptosiphon population (DFW 2017 Status Review).
Non-native slugs are generalist herbivores that have been shown to negatively affect seedling
survival of a wide range of plant species (Rathcke 1985; Buschmann et al. 2005; Strauss et al.
2009), and could potentially be grazing on coast yellow leptosiphon. Generalist herbivores
such as slugs can reduce plant density and biomass, as well as alter species diversity within
vegetation communities (Buschmann et al. 2005). The Department does not have any specific
information on the impacts of non-native slugs to coast yellow leptosiphon, but it is possible
that herbivory from slugs could negatively impact this species' survival.
Impacts from Invasive Species (Competition and other Factors)
Invading alien species cause major environmental damages and losses and are a significant
risk factor leading to extinction of threatened and endangered species (Pimentel et al. 2004;
Conser and Conner 2009), second only to habitat loss and fragmentation (Wilcove et al. 1998;
Randall and Hoshovsky 2000). Compared to other threats to biodiversity, invasive non-native
plants present a complex problem that is difficult to manage and has long-lasting effects. North
America has accumulated the largest number of naturalized plants in the world (van Kleunen
et al. 2015), and many non-native plant species have established within California,
dramatically changing the state's ecological landscape (Conser and Connor 2009). Many
studies hypothesize or suggest that competition is the process responsible for observed
invasive species impacts to biodiversity; however, invasive species may also impact native
ecosystems by altering environmental conditions and resource availability (D'Antonio and
Vitousek 1992; Levine et al. 2003). Invasive species may threaten native populations through
competition for light, water, or nutrients; allelopathic mechanisms; alteration of soil chemistry;
thatch accumulation that inhibits seed germination and seedling recruitment; changes in
natural fire frequency; disruptions to pollination or seed-dispersal mutualisms; changes in soil
microorganisms; or other mechanisms. The magnitude of invasive species impacts in
6
Mediterranean habitats, such as those in California, largely depends on characteristics of the
invading species and the habitat being invaded (Fried et al. 2014). The invader's life form and
ability to form very dense stands have an effect on the magnitude of impacts, with creeping
plant species such as freeway iceplant having greater effect (Gaertner et al. 2009; Fried et al.
2014). Invasive species may also influence native species colonization rates, and may thus
lead to declines in local diversity over longer timescales (Yurkonis and Meiners 2004). Studies
have not been conducted on the impact of invasive species on coast yellow leptosiphon
specifically; however, negative impacts of plant invasions on Mediterranean ecosystems have
been well demonstrated (Gaertner et al. 2009; Fried et al. 2014).
The coast yellow leptosiphon population is threatened by encroachment of non-native invasive
plants, especially invasive freeway iceplant that is a highly-rated noxious weed by the
California Invasive Plant Council (Cal-IPC 2017). Freeway iceplant is a low-growing, creeping
succulent perennial plant that roots at the nodes and often forms deep mats covering large
areas. Originating from South Africa, is one of the most widespread, non-native plants in the
Mediterranean coastal ecosystems throughout the world, and is considered a severe threat to
the native plant communities it invades (Albert 1995; Santoro et al. 2011). In California, it
occurs along the coast and on the Channel Islands, especially in areas with a warm winter
climate (Cal- IPC 2017). Originally introduced into California in the early 1900s to stabilize soil
along railroad tracks, the California Department of Transportation soon began using it widely to
line highways. It has also been widely promoted as an ornamental plant for home gardens
(Albert 1995, 2000). Because this plant spreads easily by seed and vegetative means, it has
spread beyond landscape plantings and has invaded coastal habitats, including the coastal
prairie where coast yellow leptosiphon grows. Freeway iceplant forms nearly impenetrable
mats that dominate the landscape, and it competes directly with native plant species for light,
nutrients, water, and space (D'Antonio and Haubensak 1998). The fleshy fruits often bear
more than one thousand small seeds (Bartomeus and Vila 2009) that are eaten and widely
dispersed by several mammals such as rabbits (D'Antonio 1990) and rats (Bourgeois et al.
2005). It competes aggressively with native plant species, achieving high rates of space
colonization, which suppresses growth and establishment of other plants (D'Antonio and
Mahal) 1991; Albert 1995; Suehs et al. 2004; Vila et al. 2006). Furthermore, it also interacts
indirectly with native vegetation by altering soil chemistry by lowering pH (Conser and Connor
2009). Although freeway iceplant was originally used to stabilize soil and control erosion, it can
actually contribute to erosion and landslides. It has shallow roots that do not hold soil well, and
it absorbs ample water during rain events, becoming so heavy that it can slump off of steep
hillsides and cliffs, pulling soil down with it (Spitzer 2002). Freeway iceplant covers the bluffs in
much of the habitat near the coast yellow leptosiphon population, and it is growing on the bluff
immediately adjacent to the coast yellow leptosiphon population and is encroaching into the
population.
Other non-native plant species, such as rough cat's ear, rye grass, hare barley, and cut-leaved
plantain, are also present growing in and around the coast yellow leptosiphon population.
These invasive species may threaten the coast yellow leptosiphon population through a variety
of mechanisms, including competition for light, water, or nutrients; thatch accumulation that
inhibits seed germination and seedling recruitment; disruptions to pollination or seed-dispersal
mutualisms; or other mechanisms (D'Antonio and Haubensak 1998).
The coast yellow leptosiphon population will likely continue to experience ongoing and
increasing inputs of invasive plant propagules from nearby populations and other sources. The
7
area is frequently used by pedestrians, who can serve as vectors for invasive species into the
area. Habitat disturbances resulting from the close proximity of the population to urban
development also provides opportunities for invasive species populations to establish and
expand. In addition, the proposed development on the adjacent property would likely increase
the input of invasive plant species from the spread of landscape plants into the area, and will
increase disturbance and habitat modification, providing favorable habitat for invasive species.
Other Natural Events or Human-Related Activities
Bluff-Top Erosion and Rising Ocean Levels—The coast yellow leptosiphon population is
located on Vallemar Bluff, approximately 8 meters (27 feet) from the edge of the bluff, and
bluff-top erosion and rising ocean levels pose a serious threat to this species. Rainfall and
wave splash or spray cause erosion of the bluff face. Additionally, slope instability results in
landslides along the coastal bluff face, resulting in landward recession of the top edge of the
coastal bluff. Coastal bluff landslides are caused by undermining the base of the bluff or from
saturation of the bluff edge or bluff face (Haro, Kasunich & Associates, Inc. 2015). A coastal
bluff recession study was prepared by Haro, Kasunich & Associates, Inc., Consulting
Geotechnical and Coastal Engineers (2015). Historical satellite photos and maps were
reviewed and compared with the bluff edge position as surveyed in 2014. The results indicated
that the coastal bluff had receded inland up to 14.6 meters (48 feet) between.1908 and 2014,
which is a long term historical bluff recession rate of about 0.14 meter (0.45 foot) per year.
Results of the study also indicated that about 3 to 5 meters (10 to 18 feet) of bluff recession
occurred between 1986 and 2014, which is a long term historical bluff recession rate of about
0.11 to 0.20 meters (0.36 to 0.64 feet) per year. Future bluff and coastal recession risk was
estimated using the long-term historical average annual erosion rates as a minimum. Results
suggested that a minimum of 6.9 meters (22.5 feet) of bluff recession will occur at Vallemar
Bluff in the next 50 years (by the year 2065). Mean sea level along the California coast is
expected to rise between 1.0 to 1.4 meters (3.3 to 4.6 feet) by the year 2100 due to climate
change (Heberger et al. 2009), and the accelerating rate of sea level rise will likely result in
increased future recession rates compared to average historical rates (Haro, Kasunich &
Associates, Inc. 2015). Accelerated future sea level rise is expected to result in an estimated
additional 1.7 meters (5.5 feet) of recession over the next 50 years, for a total of 8.6 meters (28
feet) of recession (Haro, Kasunich & Associates, Inc. 2015).
Projected future bluff edge recession was measured from where the bluff is considered stable
as determined by Haro, Kasunich & Associates, Inc. (2015). They used the projected stable
edge to project future recession and arrived at an estimated 50-year coastal recession setback
line for development on Vallemar Bluff using the projected rates of recession described above.
The 50-year setback is considered the minimum distance necessary to provide a stable
building site of a 50-year lifetime of a proposed structure. The portion of the bluff seaward of
the 50-year setback line, which supports a large portion of the coast yellow leptosiphon
population, is considered to be vulnerable to erosion over the next 50 years. It is likely that the
coast yellow leptosiphon population, which is perched near the bluff edge, has been steadily
reduced by cliff erosion. Based on the study conducted by Haro, Kasunich & Associates, Inc.,
the coast yellow leptosiphon population is located on a portion of the bluff that is highly
susceptible to erosion over the next 50 years. If the bluff erodes to the 50-year setback line
that accounts for rising sea level, approximately 80 percent of the coast yellow leptosiphon
population will be destroyed. Erosion of the bluff presents a significant threat to coast yellow
leptosiphon and could lead to the extinction of the species.
8
Direct physical impacts—The coast yellow leptosiphon population is threatened by other
human-related activities, specifically trampling from foot traffic. People commonly walk on the
bluff where the coast yellow leptosiphon population occurs, which may damage or kill.coast
yellow leptosiphon individuals through direct trampling of plants. In addition, there is nothing to
prevent people from riding their bicycles on the bluff, which would further impact the coast
yellow leptosiphon population. The property is easily accessible to the public, and a foot trail
has been worn along the bluff that passes along the edge of the coast yellow leptosiphon
population. A bench is present near the population overlooking the ocean, attracting visitors to
cut through the coast yellow leptosiphon population to view the ocean. In addition to direct
trampling of plants, human use of the site also increases disturbance and compaction of soil
and facilitates the spread of invasive plant species. No barriers exist around the coast yellow
leptosiphon population to protect plants from foot traffic and trampling. The proposed
development will result in increased human activity in the area, thus increasing the threat to
coast yellow leptosiphon from foot traffic and other human impacts.
Climate Change—Warming of the climate system is unequivocal, and since the 1950s, many
of the observed changes are unprecedented over decades to millennia (IPCC 2014). Climate
change presents a major challenge to the conservation of California's natural resources, and it
will intensify existing threats and create new threats to natural systems. Department staff
conducted an assessment of the vulnerability of coast yellow leptosiphon to climate change
using the NatureServe Climate Change Vulnerability Index Version 3.02 (NatureServe 2016).
Based upon the Department's assessment, coast yellow leptosiphon likely has a climate
change vulnerability index value of Highly Vulnerable (NV), indicating that available evidence
suggests that abundance and/or range extent within the geographical area of the species is
likely to decrease significantly by the year 2050. However, some ecological and life history
information used for the climate change vulnerability assessment is not yet known for coast
yellow leptosiphon. In particular, the Department does not know the mechanisms or species
required for effective pollination of coast yellow leptosiphon, the mechanisms used by coast
yellow leptosiphon for seed,dispersal, or coast yellow leptosiphon's seed dispersal distance.
Furthermore, the Department does not know whether or to what extent competing plant
species such as freeway iceplant will be favored by projected future climates. Despite the lack
of information about some of the ecological and life history information for coast yellow
leptosiphon, the confidence in the vulnerability index score is very high based on the results of
the Monte Carlo simulation used in the index (Young et al. 2015).
Vulnerability of Small Populations—Coast yellow leptosiphon has an exceptionally limited
distribution, with only one population that occupies a very small area. The Department
recognizes that species with small numbers of populations and small population sizes are
highly vulnerable to extinction due to stochastic (chance) demographic, environmental, and
genetic events (Shaffer 1981, 1987; Dirzo and Raven 2003; Groom et al. 2006; Primack 2006).
Chance events such as a landslide at the bluff edge could result in the loss of all or a
significant part of the coast yellow leptosiphon population. Species with small numbers of
populations or small populations may also be subject to increased genetic drift and inbreeding,
which can affect population viability (Menges 1991; Ellstrand and Elam 1993). Due to the
vulnerability and rarity of coast yellow leptosiphon, the loss of any portion of the population
would represent the loss of a significant portion of this species' genetic diversity and total
range, and could result in its extinction.
9
IV. Final Determination by the Commission
The Commission has weighed and evaluated the information for and against designating coast
yellow leptosiphon as an endangered species under CESA. The information includes scientific
and other general evidence in the Petition; the Department's Evaluation; the Department's
status review; the Department's related recommendations; written and oral comments received
from members of the public, the regulated community, various public agencies, and the
scientific community; and other evidence included in the Commission's record of proceedings.
Based upon the evidence in the record, the Commission has determined that the best scientific
information available indicates that the continued existence of coast yellow leptosiphon is in
serious danger or threatened by present or threatened modifications or destruction of the
species' habitat, predation, competition, disease, or other natural occurrences or human-
related activities, where such factors are considered individually or in combination. (see
generally Cal. Code Regs., tit. 14, § 670.1, subs. (i)(1)(A); Fish & G. Code, §§ 2062, 2067.)
The Commission determines that there is sufficient scientific information to indicate that
designating coast yellow leptosiphon as an endangered species under CESA is warranted at
this time and that, with adoption and publication of these findings, coast yellow leptosiphon for
purposes of its legal status under CESA and further proceedings under the California
Administrative Procedure Act, shall be listed as endangered.
10
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13
BUTTE COUNTY
ADMINISTRATION
SEP 1 2 2018
California Fish and Game Commission
OROVILLE,CALIFORNIA
NOTICE OF FINDINGS
Tricolored Blackbird
(Agelaius tricolor)
NOTICE IS HEREBY GIVEN that the California Fish and Game Commission (Commission), at
a meeting in Ventura, California on April 19, 2018, found pursuant to Fish and Game Code
Section 2075.5, that the information contained in the petition to list tricolored blackbird
(Agelalus tricolor) and other information in the record before the Commission, warrants adding
tricolored blackbird to the list of threatened species under the California Endangered Species
Act (CESA) (Fish & G. Code, § 2050 et seq.). (see also Cal. Code Regs., tit. 14, § 670.1,
subset. (i).)
NOTICE IS ALSO GIVEN that, at its August 23, 2018 meeting in Fortuna California, the
Commission adopted the following findings outlining the reasons for its determination.
I. Background and Procedural History
Petition History
On August 19, 2015, the California Fish and Game Commission (Commission) received "A
Petition to List Tricolored Blackbird (Agelaius tricolor) as Endangered under the California
Endangered Species Act and Request for Emergency Action to Protect the Species", as
submitted by the Center for Biological Diversity. Commission staff transmitted the petition to
the California Department of Fish and Wildlife (Department) pursuant to Fish and Game Code
Section 2073 on August 20, 2015, and published a formal notice of receipt of the petition on
September 4, 2015 (Cal. Reg. Notice Register 2015, No. 36-Z, p. 1514).
The Commission formally received the Department's petition evaluation and recommendation,
"Evaluation of the Petition from the Center for Biological Diversity to List Tricolored Blackbird
(Agelaius tricolor) as Endangered Under the California Endangered Species Act," at a meeting
on October 8, 2015 in Los Angeles, California (Fish & G. Code, §§ 2073.5 & 2074.2; Cal. Code
Regs., tit. 14, § 670.1, subsets. (d) & (e)). At its public meeting on December 10, 2015, in San
Diego, California, the Commission considered the petition, the Department's petition evaluation
and recommendation, and comments received. The Commission determined that sufficient
information existed to indicate the petitioned action may be warranted and accepted the
petition for consideration. Upon publication of the Commission's notice of its findings, tricolored
blackbird was designated a candidate species on January 8, 2016 (Cal. Reg. Notice Register
2016, No. 2-Z, p. 57).
Status Review Overview
The Commission's action designating tricolored blackbird as a candidate species triggered the
Department's process for conducting a status review to inform the Commission's decision on
whether to list the species. At its scheduled public meeting on December 8, 2016, in San
Diego, California, the Commission granted the Department a six-month extension to complete
the status review and facilitate external peer review. The Commission formally received the
1
Department's report to the Commission titled "A STATUS REVIEW OF THE TRICOLORED
BLACKBIRD (Agetaius tricolor) IN CALIFORNIA" on February 8, 2018. On April 19, 2018, in
Ventura, California, the Commission found that the information contained in the petition to list
tricolored blackbird and the other information in the record before the Commission warrants
listing tricolored blackbird as a threatened species under the CESA.
Species Description
Tricolored blackbird was first collected by Thomas Nuttall in 1836 near Santa Barbara,
California (Nuttall 1840, Baird et al. 1874). A male specimen was sent to John James Audubon
who described it as a unique form of blackbird in his well-known Ornithological Biography
(Audubon 1839).
Tricolored blackbird is sexually dimorphic, with the breeding male plumage entirely black
except for the bright red lesser wing coverts forming a conspicuous red patch ("shoulder" or
"epaulets") on the wing and white median coverts forming a distinct border to the red. The
black body plumage is glossed bluish when viewed in sunlight. The female is mostly dark
brown dorsally and heavily streaked ventrally with dark brown streaks merging to form a
largely solid dark brown belly. The head of the female is indistinctly patterned with a whitish
supercilium, malar, chin, and throat (Beedy et al. 2017).
Although similar in appearance to the related red-winged blackbird (A. phoeniceus), several
features can be used to distinguish the two species in breeding plumage (described by Nuttall
1840, Cooper 1870, Baird et al. 1874). The black plumage of the tricolored blackbird male has
a soft bluish luster that is lacking in the red-winged blackbird. The lesser wing coverts (the red
"shoulder") on the breeding male tricolored blackbird are a much deeper red (described as
crimson, carmine, or the color of venous blood) compared to the brighter red with a tinge of
orange (vermilion or scarlet) in the red-winged blackbird. The median coverts in tricolored
blackbird are white (pale-yellowish when fresh) and create a stark contrast between the black
and red feathers on the wing, whereas in the red-winged blackbird they are generally yellowish
(or black in the subspecies that breeds in much of the Central Valley). The bill of tricolored
blackbird averages thinner and can appear more sharply pointed. In flight, the wings of
tricolored blackbird appear to have a more pointed shape (versus rounded in the red-winged
blackbird) due to differences in length of the primary flight feathers. Female tricolored
blackbirds have darker plumage than most female red-winged blackbirds, although this
difference is less pronounced in the Central Valley where the subspecies of red-winged
blackbird is relatively dark (Beedy et al. 2017)
II. Statutory and Legal Framework
The Commission, as established by the California Constitution, has exclusive statutory
authority under California law to designate endangered, threatened, and candidate species
under CESA (Cal. Const., art. IV, § 20, subd. (b); Fish & G. Code, § 2070). The CESA listing
process for tricolored blackbird began in the present case with the Petitioners' submittal of the
Petition to the Commission on August 19, 2015. The regulatory and legal process that ensued
is described in some detail in the preceding section above, along with related references to the
Fish and Game Code and controlling regulation. The CESA listing process generally is also
described in some detail in published appellate case law in California, including:
2
• Mountain Lion Foundation v. California Fish and Game Commission (1997) 16 CaI.4th1
105, 114-116;
• California Forestry Association v. California Fish and Game Commission (2007) 156
Cal.App.4th 1535, 1541-1542;
• Center for Biological Diversity v. California Fish and Game Commission (2008) 166
Cal.App.4th 597, 600; and
• Natural Resources Defense Council v. California Fish and Game Commission (1994) 28
Cal.App.4th 1104, 1111-1116.
The "is warranted" determination at issue here for tricolored blackbird stems from Commission
obligations established by Fish and Game Code Section 2075.5. Under this provision, the
Commission is required to make one of two findings for a candidate species at the end of the
CESA listing process; namely, whether listing a species is warranted or is not warranted. Here,
with respect to tricolored blackbird, the Commission made the finding under Section
2075.5(e)(2) that listing the species as threatened is warranted.
The Commission was guided in making these determinations by statutory provisions and other
controlling law. The Fish and Game Code, for example, defines an endangered species under
CESA as "a native species or subspecies of a bird, mammal, fish, amphibian, reptile or plant
which is in serious danger of becoming extinct throughout all, or a significant portion, of its
range due to one or more causes, including loss of habitat, change in habitat, over exploitation,
predation, competition, or disease." (Fish & G. Code, § 2062.) Similarly, the Fish and Game
Code defines a threatened species under CESA as "a native species or subspecies of a bird,
mammal, fish, amphibian, reptile or plant that, although not presently threatened with
extinction, is likely to become an endangered species in the foreseeable future in the absence
of the special protection and management efforts required by this chapter." (Id., § 2067.)
The Commission also considered Title 14, Section 670.1, subsection (i)(1)(A), of the California
Code of Regulations in making its determination regarding tricolored blackbird. This provision
provides, in pertinent part, that a species shall be listed as endangered or threatened under
CESA if the Commission determines that the species' continued existence is in serious danger
or is threatened by any one or any combination of the following factors:
1. Present or threatened modification or destruction of its habitat,
2. Overexploitation,
3. Predation,
4. Competition,
5. Disease, or
6. Other natural occurrences or human-related activities.
Fish and Game Code Section 2070 provides similar guidance. This section provides that the
Commission shall add or remove species from the list of endangered and threatened species
under CESA only upon receipt of sufficient scientific information that the action is warranted.
Similarly, CESA provides policy direction not specific to the Commission per se, indicating that
all state agencies, boards, and commissions shall seek to conserve endangered and
threatened species and shall utilize their authority in furtherance of the purposes of CESA.
3
(Fish & G. Code, § 2055.) This policy direction does not compel a particular determination by
the Commission in the CESA listing context. Nevertheless, "'Maws providing for the
conservation of natural resources' such as the CESA 'are of great remedial and public
importance and thus should be construed liberally." (California Forestry Association v.
California Fish and Game Commission, supra, 156 Cal. App.4th at pp. 1545-1546, citing San
Bernardino Valley Audubon Society v. City of Moreno Valley (1996)44 Cal.App.4th 593, 601;
Fish & G. Code, §§ 2051, 2052.)
Finally in considering these factors, CESA and controlling regulations require the Commission
to actively seek and consider related input from the public and any interested party (see, e.g.,
Id., §§ 2071, 2074.4, 2078; Cal. Code Regs., tit. 14, § 670.1, subsection (h)). The related
notice obligations and public hearing opportunities before the Commission are also
considerable (Fish & G. Code, §§ 2073.3, 2074, 2074.2, 2075, 2075.5, 2078; Cal. Code Regs.,
tit. 14, § 670.1, subsection (c), (e), (g), (i); see also Gov. Code, § 11120 et seq.). All of these
obligations are in addition to the requirements prescribed for the Department in the CESA
listing process, including an initial evaluation of the petition and a related recommendation
regarding candidacy, and a review of the candidate species' status culminating with a report
and recommendation to the Commission as to whether listing is warranted based on the best
available science (Fish & G. Code, §§ 2073.4, 2073.5, 2074.4, 2074.6; Cal. Code Regs.,
tit. 14, § 670.1, subsection (d), (f), (h)).
Ill. Factual and Scientific Bases for the Commission's Final Determination
The factual and scientific bases for the Commission's determination that designating tricolored
blackbird as a threatened species under CESA is warranted are set forth in detail in the
Commission's record of proceedings including the Petition, the Department's Evaluation, the
Department's status review, written and oral comments received from members of the public,
the regulated community, tribal entities, the scientific community and other evidence included
in the Commission's record of proceedings.
The Commission determines that the continued existence of tricolored blackbird in the state of
California is in serious danger or threatened by one or a combination of the following factors as
required by the California Code of Regulations Title 14, Section 670.1, subsection (i)(1)(A):
1. Present or threatened modification or destruction of its habitat,
2. Overexploitation,
3. Predation,
4. Competition,
5. Disease, or
6. Other natural occurrences or human-related activities.
The Commission also determines that the information in the Commission's record constitutes
the best scientific information available and establishes that designating tricolored blackbird as
a threatened species under CESA is warranted. Similarly, the Commission determines that
tricolored blackbird, while not presently threatened with extinction, is likely to become an
endangered species in the foreseeable future in the absence of the special protection and
management efforts required by CESA.
4
The items highlighted here and detailed in the threats section represent only a portion of the
complex issues aired and considered by the Commission during the CESA listing process for
tricolored blackbird. Similarly, the issues addressed in these findings represent some, but not
all of the evidence, issues, and considerations affecting the Commission's final determination.
Other issues aired before and considered by the Commission are addressed in detail in the
record before the Commission, which record is incorporated herein by reference.
Background
The Commission bases its "is warranted" finding for tricolored blackbird most fundamentally on
the fact that tricolored blackbird nests and breeds in large colonies coupled with the current
downward population trend influenced by a combination of other threats.
Social species might experience increased risk of population declines and extinction, and
obligate colonial nesting birds may be especially vulnerable. In these species, there is
generally a positive relationship between individual fitness (i.e., reproduction or survival) and
population size or density, a concept which is broadly referred to as the Allee effect (Stephens
and Sutherland 1999). In modern times, three colonial and highly social bird species have
gone extinct in North America north of Mexico, including the Passenger Pigeon (Ectopistes
migratorius), the Carolina Parakeet (Conuropsis carolinensis), and the Great Auk (Pinguinus
impennis) (Cook and Toft 2005).
Tricolored blackbirds may benefit from social and colonial behaviors by reducing mortality due
to predation during the nesting cycle and by facilitating food finding and information sharing.
Smaller groups of birds would likely retain the ability to locate and use secure nesting
substrates, but small colonies might lose the potential benefits of predator satiation and of
social food finding and information sharing. (DFW Status Review 2018).
Although tricolored blackbird has been observed to nest in very small colonies (as few as 4
nests), the species has not been observed to nest as single pairs. Very small colonies (<100
birds) are quite rare, and although nesting success varies greatly across colonies of all sizes,
there is evidence that small colonies are not as successful as larger colonies (Payne 1969),
and that larger colonies produce more young per female (Hamilton 1993, Meese 2013,
Weintraub et al. 2016). Reductions in population size may make tricolored blackbird more
vulnerable to additional declines due to inherent natural history factors, but the degree to which
a small population would limit the species' ability to survive and reproduce is not known.
The fact that half or more of the total tricolored blackbird population will often occur in a small
number of large colonies in silage fields during the first nesting attempt makes the species
vulnerable to losses of productivity (Cook and Toft 2005, Meese 2012, Beedy et al. 2017). In
2011, 65% of the total known population was located at only six colony sites in Merced, Kern,
and Tulare counties (Kyle and Kelsey 2011). This concentration of large portions of the
population makes the species vulnerable to a number of potential threats, especially colony
destruction through harvest, predation, or extreme weather events (Weintraub et al. 2016).
5
Threats
Present or Threatened Modification or Destruction of Habitat
Of the estimated four million acres (16,187 square kilometers [km2]) of wetlands that existed in
the Central Valley in the 1850s that could have been available to tricolored blackbirds as
nesting substrate, only about 5% remain. The conversion of wetland nesting habitat to
agricultural and urban uses has been implicated in the long-term decline of the species: Neff
(1937) observed, "[t]he destruction of [tricolored blackbird] nesting habitats by man is of most
importance," and cited reclamation and drainage as key factors in the loss of many favorable
sites, along with "dredging or cleaning of reservoirs, marshes, and canals in order to destroy
the growths of cattails and tules." Only about 15% of the four million acres (16,187 km2) of
wetlands that existed in the Central Valley in the 1850s remained when Neff conducted his
work in the 1930s, and about 40% of those remaining wetlands were lost between 1939 and
the 1980s (Frayer et al. 1989). Of the freshwater emergent wetlands most likely to be used by
breeding tricolored blackbirds in the Central Valley, 50% were lost between 1939 and the
1980s, with an average loss of 5,200 acres (2,104 hectares) per year (Frayer et al. 1989).
These losses were primarily due to conversion of wetlands to agriculture.
DeHaven et al. (1975b) found no nesting substrate at several locations in Los Angeles, Kern,
Sacramento, and Yolo counties where earlier researchers had studied the species.
Subsequent investigators have continued to document habitat loss at known prior breeding
colony locations through the present. For example, Beedy et al. (1991) found that 9.3%
(n = 17) of the 183 known colony locations used in the 1980s were extirpated by 1990 through
permanent removal of nesting habitat. Hamilton et al. (1999) observed the removal of a
wetland that had supported a productive breeding colony in 1998. DeHaven (2000) noted the
loss of several breeding colonies in Sacramento County to urban development and the
expansion of vineyards. Humple and Churchwell (2002) reported on the draining of a wetland
and the removal of Himalayan blackberry that had previously supported breeding colonies.
Hamilton (2004b) documented the loss or destruction of cattail nesting substrates that had
supported 90,000 breeding birds between 1994 and 2004. During the 2017 statewide survey,
local experts and survey participants were asked to score the suitability of nesting substrate for
all sites visited. Of the 636 sites for which scores were reported during the survey or during
pre-survey site visits, 70 sites (11%) were scored as permanently unsuitable, usually due to
development or conversion to permanent crops like orchards or vineyards; an additional 80
sites had no nesting substrate present during the survey and 101 sites had vegetation present,
but were considered unsuitable by the survey participant. Based on this habitat assessment,
about 60% of known historical breeding sites supported suitable nesting substrate during the
2017 season. (DFW Status Review 2018).
The majority of the wetlands in the Central Valley are managed lands that are maintained by
application of water, and many areas undergo occasional land recontouring or vegetation
control to maintain desired conditions. As of 2006, there were about 205,000 acres (830 km2)
of managed wetlands in the Central Valley (CVJV 2006). Most managed wetlands
(approximately 90%) are flooded primarily in the fall and winter for wintering waterfowl (i.e.,
seasonal wetlands) and are unlikely to provide suitable nesting substrate for tricolored
blackbirds. A small proportion are managed as semi-permanent or permanent wetlands that
hold water during the spring and summer (Iglecia and Kelsey 2012) and are often managed to
support brood habitat for waterfowl. The small proportion of semi-permanent and permanent
6
wetlands may provide suitable nesting substrate for breeding tricolored blackbirds, depending
on management practices.
The availability of novel, nonnative upland nesting substrates may have lessened the impact of
the decline in Central Valley wetlands to the tricolored blackbirds population (Cook and Toll
2005). However, these nonnative vegetation types are often considered undesirable and are
frequently removed (DFW Status Review 2018).
The extent of foraging habitat required for successful breeding is much greater than the extent
of nesting substrate (DFW Status Review 2018). The abundance of insect prey in foraging
habitat has been linked to reproductive success, and tricolored blackbirds may choose
breeding locations in part based on the local prey populations (DFW Status Review 2018).
Because insect populations are variable and unpredictable from year to year, the tricolored
blackbird population likely requires much more foraging habitat on the landscape than is used
in any given year, and once lost, large landscapes with suitable habitat are difficult to replace
(DFW Status Review 2018). For these reasons, loss of foraging habitat is likely as important, or
more so, than the documented losses of nesting substrate to the long-term viability of tricolored
blackbirds (DFW Status Review 2018).
The loss of foraging habitat has been suggested as a likely cause of decline in southern
California (Hamilton et al. 1995, Cook 2010). The extirpation of colonies from most of the
coastal lowlands in southern California, despite the presence of more numerous marsh habitats
relative to inland areas, suggests that foraging habitat sufficient to support breeding colonies is
the population's limiting factor (Unitt 2004). Loss of habitat, particularly foraging habitat, has
been suggested as the greatest threat to the survival of the species in southern California. In
western Riverside County, where the majority of the southern California population occurs,
large residential and commercial developments are planned for much of the San Jacinto Valley.
This will likely result in substantial loss of dairy lands and the alfalfa fields used by tricolored
blackbirds that nest both on and off the San Jacinto Wildlife Area (R. Cook pers. comm.).
Hamilton et al. (1992) reported on the pervasive loss of foraging habitat near breeding colony
sites due to expansion of cultivated agriculture and the conversion of existing agriculture to
incompatible crops in the Central Valley, and considered this the primary threat to population
abundance. DeHaven (2000) observed widespread habitat loss due to urban expansion and
agricultural conversions to vineyards and orchards relative to the 1970s when he and others
conducted tricolored blackbird research across the state, and suggested that habitat loss was a
primary driver of continued population declines. Conversion of pastures and crops suitable for
foraging by tricolored blackbirds was observed in Placer, Sacramento, Stanislaus, and Tulare
counties. DeHaven (2000) noted especially extensive losses in Sacramento County, where
urban development and expansion of vineyards had removed thousands of acres of high-
quality habitat. More than 5,000 acres (20 km2) of habitat had been converted to vineyards in
just a two-year period from 1996 to 1998, resulting in the loss of known breeding colony
locations.
Grasslands have been identified as one of the most vulnerable habitats across North America,
and many grassland species have experienced steep population declines in recent decades
(NABCI 2016). A great deal of effort has been expended on conserving the grasslands in the
central part of North America from the Great Plains to northern Mexico (Knopf and Skagen
7
2012). The grasslands of California have not received the same level of conservation attention,
although losses of grasslands in California have been extensive.
Soulard and Wilson (2015) used Landsat (satellite) data to analyze land-use and land-cover
change in the Central Valley from 2000 to 2010, and compared this to changes in the valley
since 1973. The largest land-cover trend from 2000 to 2010 occurred in grassland/shrubland
habitats. During this 10-year period, an estimated 79,200 acres (321 km2) of grasslands and
shrubiands were lost, representing a 5% decrease in the Central Valley over 10 years. Over
the longer period from 1973 to 2010, grasslands and shrublands declined by 22% (a loss of
476,900 acres [1,930 km2]), due mainly to conversions to more intensive agriculture and urban
development. Although many of the grassland losses were due to agricultural intensification,
losses of agriculture to urban development resulted in relatively little net change in area of
agriculture in the Central Valley from 1973 to 2010. (DFW Status Review 2018).
Cameron et al. (2014) analyzed time series land cover data from the California Farmlands
Mapping and Monitoring Program collected between 1984 and 2008 to evaluate rangeland
habitat (grassland, shrubland, and woodland) conversion in California. The area evaluated
covers much of the breeding range of tricolored blackbird except for southern California. About
483,000 acres (1,955 km2) of rangelands were converted during this 20+ year period, with
urban and rural development and conversion to more intensive agricultural uses accounting for
most (approximately 90%) of the rangeland loss. Agricultural intensification was primarily due
to increases in vineyards and orchards, but smaller amounts of other agricultural crops that
may provide foraging habitat for tricolored blackbirds were also responsible for grassland loss.
The San Joaquin Valley region, which in recent decades has been the center of abundance for
breeding tricolored blackbirds during the early nesting season, experienced the largest amount
of rangeland conversion (DFW Status Review 2018).
Due to the continued expansion of nut trees and vineyards that replace grasslands,
shrublands, or agricultural crops that provide insects required for breeding (e.g., alfalfa),
regions that were previously occupied by thousands of birds have now become permanently
unsuitable for breeding because of insufficient foraging habitat (Meese 2016). For example,
the acreage of pistachio orchards in the Central Valley has grown exponentially in recent years
and the acreage of almonds continues to increase. The five leading pistachio producing
counties in California have also supported a large proportion of the tricolored blackbird
breeding population in recent years (Kern, Tulare, Kings, Fresno, and Madera counties), with
Kern County alone supporting 42% of pistachio production in 2012 (Geisseler and Horvath
2016). These regions of habitat loss in the San Joaquin Valley have also experienced the
largest regional declines in the tricolored blackbird breeding population. In the central Sierran
foothills, many colony sites and the surrounding foraging landscape are zoned for
development, and several development projects that may affect tricolored blackbird habitat
have moved forward in recent years (Airola et al. 2015a, 2016). Statewide, the proportion of
grasslands within 3 miles (4.8 km) of occupied breeding colony locations declined significantly
from 2008 to 2014 (from about 30% to 25%; NAS 2017).
Future development in California is projected to be concentrated in several core areas of the
tricolored blackbird range, including the Central Valley, the foothills of the Sierra Nevada, and
on both sides of the Transverse Ranges in southern California (Jongsomjit et al. 2013), which
would further reduce or degrade the available foraging landscape for breeding colonies. The
proportion of grasslands in the landscape surrounding potential breeding sites has been shown
8
to be the most important land cover type in predicting the occurrence of breeding tricolored
blackbirds, and the proportion of alfalfa in the foraging landscape is highly correlated with
colony size during the early nesting season (NAS 2017). Combined with regular loss of nesting
substrate, the ongoing loss of foraging habitat makes it less likely that these essential breeding
habitat requirements will co-occur on the landscape, with the result being a reduced number of
locations suitable for successful breeding and foraging by tricolored blackbird colonies (DFW
Status Review 2018).
Overexploitation
The tricolored blackbird colonies that form on agricultural grain fields early in the breeding
season are often the largest colonies formed each year, and the complete destruction of these
colonies due to harvest can be especially damaging to annual blackbird productivity (Arthur
2015). Normal harvesting activities typically coincide with the breeding season and the harvest
of fields that contain nesting colonies results in nest destruction and the loss of eggs or
nestlings. The cutting of grain has also killed adult tricolored blackbirds but most adults appear
to survive harvest operations.
Shortly after the discovery of grain colonies in the San Joaquin Valley, Hamilton et al. (1992)
observed the loss of a 15,000-bird colony to harvest. As early as 1993, the USFWS intervened
to encourage harvest delays and protect the largest known breeding colony (Hamilton 1993).
Since then, colony protection through crop purchase or delayed harvest has been the primary
conservation action implemented for the species (see Existing Management section), with
mixed success. Despite annual attempts to locate and protect large colonies since the early
1990s, losses to harvest have occurred in most years, with 2010 and 2016 being the only
years with no known losses to harvest. For context, a brief list of some of the known large
losses follows. Two large colonies representing more than 60,000 breeding birds were lost due
to harvest in 1994 (Hamilton et al. 1995). The two largest breeding colonies in 1995 were
destroyed during harvest of the grain nesting-substrate (Beedy and Hamilton 1997). At least
one colony of 14,000 birds was harvested in 1999 and four colonies were lost to harvest
operations in 2000 (Hamilton et al. 1999, Hamilton 2000). Two colonies totaling approximately
80,000 breeding birds were lost to harvest operations in 2003 (Cook and Toll 2005). Especially
large losses occurred in 2004, 2006, 2007, and 2008, when the largest colonies or the majority
of grain colonies were lost (Meese 2009b). In 2008, several of the largest known colonies were
destroyed, with six colonies being cut that hosted 140,000 breeding birds (Meese 2008). At
least three colonies were lost to harvest in 2011, including the largest known colony, which
supported 17% of the total known population (Kyle and Kelsey 2011, Meese 2011). The largest
colony in southern California in 2013, which contained most of the southern California
population, suffered complete reproductive failure when the field was cut (WRC-MSHCP
2014). At least two colonies in grain fields were destroyed in 2014 during the harvest of nesting
substrate and at least three colonies were partially or totally destroyed due to harvest in 2015
(Meese 2014a, 2015b). After a breeding season with no known harvest losses in 2016, a large
colony (estimated at up to 12,500 birds) was mostly lost in 2017 when the grain nesting
substrate was cut in preparation for harvest (Colibri 2017).
Beginning in 2016, a new partnership was created through a grant from the U.S. Department
of Agriculture's Natural Resources Conservation Service, with Audubon California, dairy trade
organizations, and agencies working together to conduct outreach to dairy owners and to
detect and protect breeding colonies. The program succeeded in enrolling all landowners with
9
tricolored blackbird colonies identified on their property in 2016, and 100% of known
agricultural colonies were protected through delay of harvest. In 2017, most colonies on grain
fields at dairies were again protected, but at least one large colony in Madera County was
destroyed when the grain was cut (Colibri 2017).
Clutch size has been observed to decline in second nesting attempts (Beedy et al. 2017). The
only study to evaluate reproductive success over the course of a breeding season, which was
carried out on silage and wetland colonies in the San Joaquin Valley, showed that reproductive
success declined as the season progressed (Weintraub et al. 2016). The elimination of a first
breeding attempt may cause breeding colonies to miss the period of peak prey abundance,
thereby reducing seasonal reproductive success, as has been observed in other species
(Martin 1987). Colony destruction through harvest typically occurs well after females have laid
eggs and often after eggs have hatched, so the lost energetic input to a failed breeding attempt
and the delay before a second attempt likely reduce total annual productivity, even if birds
attempt to nest a second time (Meese 2008). Most adult tricolored blackbirds appear to nest at
least twice during the breeding season, and destruction of colonies late in the nesting cycle
could eliminate one of these attempts. In addition to the loss of eggs and nestlings, adult birds
are known to have been killed when colonies are harvested. Because nest survival and
reproductive success rates were similar in silage and wetland colonies in the San Joaquin
Valley, Weintraub et al. (2016) suggested that payments to farmers who delay harvest is a
viable conservation action for increasing productivity.
Tricolored blackbird was shown to have experienced low reproductive success from at least
2006 to 2011 (Meese 2013). A number of factors have been shown to influence reproductive
success, including predation and shortage of food, but reproductive failures caused by harvest
at breeding tricolored blackbird colonies on agricultural fields of the San Joaquin Valley may
have contributed to population declines through loss of much of the annual reproductive
potential of the species in several years. (DFW Status Review 2018).
Destruction of colonies in agricultural fields has been occurring since tricolored blackbirds were
discovered nesting in this substrate type in the early 1990s. In recent years (2015— 2017), the
protections provided to tricolored blackbird as a candidate under CESA, the availability of
funds to implement colony protection programs, law enforcement actions conducted by the
Department, and a coordinated effort by agencies, the dairy and farming industries, and
nonprofit groups, have led to a dramatic decline in this source of mortality (DFW Status Review
2018). These protections, and a resulting increase in productivity, may have contributed to
population stability observed between 2014 and 2017 (DFW Status Review 2018). However,
losses of large colonies to grain harvest have continued and the future success of breeding
colonies on agricultural crops will depend on the availability of funds to continue programs that
locate and monitor breeding colonies on grain fields early in the nesting season and
compensate farmers for delaying harvest. If the recent reinterpretation of the MBTA by the
U.S. Department of the Interior solicitor removes the prohibition on incidental take, protection
under CESA may be necessary in order to ensure continued participation in colony protection
programs.
Predation
In the early 1990s, Hamilton and others found that many breeding colonies in emergent
wetland nesting substrates suffered partial or complete destruction by predation (primarily by
10
black-crowned night-herons; Hamilton et al. 1992, 1995, Hamilton 1993), resulting in
consistently lower reproductive success in wetlands compared to other nesting substrates.
Beedy and Hamilton (1997) reported that more recently, black-crowned night-herons
eliminated all or most nests at several freshwater marsh breeding colonies. Hamilton (2000)
later reported that wetland colonies with no black-crowned night-heron predation were highly
successful. DeHaven (2000) reported that he also observed high rates of colony failure due to
predation in the 1970s, a time when the majority of the population still bred in wetland
substrates. Whether recent rates of loss to predation are similar to historical rates of loss is
unknown.
In recent decades, complete nesting failures have been caused by novel predators on
agricultural grain fields, and the increasing concentration of birds in mega-colonies may have
increased their susceptibility to nest predation (Kelsey 2008). Cattle Egrets from a single
rookery caused complete or near-complete failure of large breeding colonies in Tulare County
from 2006 to 2011 (Meese 2012). White-faced ibis prey on the eggs of tricolored blackbird, and
in 2016 caused the complete failure of a large breeding colony on a silage field in Tulare
County (Meese 2016, Beedy et al. 2017).
Although many species have been documented as predators of tricolored blackbirds, most
have not had severe effects on the population or on the breeding success at nesting colonies.
However, a few species have caused the complete failure of entire breeding colonies through
heavy predation on eggs and nestlings. In recent decades, the predators that have destroyed
entire colonies have usually been wading birds that hunt in large groups (i.e., black-crowned
night-heron, cattle egret, and white-faced ibis). These species have had significant negative
impacts on the overall productivity rate of tricolored blackbirds in several years over the last
three decades (Hamilton et al. 1995, Cook and Toft 2005, Meese 2012). A few other species,
including common raven, raccoon, and coyote have had large effects on breeding success, but
these predators have typically not caused complete colony failure or have had less widespread
effects (DFW Status Review 2018).
Other Natural Events or Human-Related Activities
Contaminants—In the two decades since their introduction, neonicotinoid insecticides have
become some of the most widely used insecticides in the world, including in California.
(Goulson 2013). They are highly effective at killing insects and have relatively low mammal
and bird toxicity; however, at higher concentrations they can have lethal and sublethal impacts
to vertebrates (Mineau and Palmer 2013). Neonicotinoids have been implicated in the decline
of invertebrate communities and, in a few cases, the decline of insectivorous birds. Ingestion of
only a few neonicotinoid-coated seeds (a single seed in the case of corn) might be sufficient to
kill a songbird, but there has been little work conducted on the availability and consumption of
treated seeds by vertebrates, and no data are available on the acute toxicity of any
neonicotinoid insecticide specifically to tricolored blackbirds (Goulson 2013, Mineau and
Palmer 2013; DFW Status Review 2018). Neonicotinoids may also have chronic toxicity effects
(exposure over longer time periods) on reproductive success, but chronic effects are even less
studied than acute effects (Mineau and Palmer 2013).
Neonicotinoids have been shown to have adverse effects on a number of non-target
invertebrate species, and may indirectly affect tricolored blackbirds through suppression of
insect prey populations (DFW Status Review 2018). They have been shown to have adverse
11
effects on a number of non-target invertebrate species, with most studies focusing on bees
(Hopwood et al. 2012, Godfray et al. 2014). In California, long-term observational data have
revealed declines in the number of butterfly species and declines in abundance for many
butterfly species in the Central Valley, both of which were negatively associated with annual
application rates of neonicotinoid insecticides (Forister et al. 2016). Imidacloprid was shown to
have a negative association with a wide variety of insectivorous bird populations in the
Netherlands, suggesting that the pesticide may have led to food deprivation in birds (Hallmann
et al. 2014).
Drought, Water Availablility, and Climate Change—Drought reduces water supply reliability
and has far-reaching impacts on most habitat types in California (DWR 2014, 2015a). Several
significant statewide droughts have occurred in California over the last century (1928-1934,
1976-1977, 1987-1992, and 2007-2009) (DWR 2015a), and California recently experienced
the three driest consecutive years of statewide precipitation in the historical record between
2012 and 2014. The winter of 2015 produced a record low statewide mountain snowpack of
only 5% of average.
Tricolored blackbirds have adapted to use a variety of novel vegetation types as nesting
substrate, but wetlands continue to support the largest number of breeding colonies each year.
Because of the need for wetlands that are flooded during the spring and summer breeding
season, the various approaches to wetland management, and the dependence on water
deliveries to maintain wetland habitats in most of the tricolored blackbird's range, assessing
the availability of suitable wetland nesting substrate in a given year is difficult. A recent method
applied reflectance to satellite imagery to identify areas of open surface water in the Central
Valley (Reiter et al. 2015). Although not an ideal approach to quantifying and assessing
distribution of wetlands, the method would identify wetlands with large amounts of open water.
In addition, identification of open water on the landscape during the tricolored blackbird
breeding season is likely a good proxy for the availability of water for wetland management.
Reiter et al. (2015) showed that open surface water declined across the Central Valley
between 2000 and 2011. Drought had a significant negative effect on open surface water in
the late summer and early fall. Cumulative years of drought resulted in a noticeable reduction
in surface water. Although not a direct measure of tricolored blackbird breeding habitat,
declines in surface water during the drought likely resulted in reduced availability of wetlands
with sufficient water to provide high quality nesting substrates.
Although more resilient to dry conditions than wetland vegetation, plants species that provide
upland nesting substrate for tricolored blackbird colonies also experience negative effects due
to drought. After several years of dry conditions during California's most recent drought, many
Himalayan blackberry copses that have historically supported tricolored blackbird colonies
were observed to be dry and mostly barren of leaves. In a few cases, extremely dry blackberry
bushes continued to be used by breeding colonies, but many were unoccupied. Milk thistle,
which provides high-quality nesting substrate across much of the tricolored blackbird range
when annual precipitation patterns support vigorous growth, was largely absent from
historically used areas until California experienced an average water year in the winter of
2015-2016 (Airola et al. 2016). The wetter weather created nesting substrate in areas that had
not been used by tricolored blackbirds in several years, and breeding colonies once again
occupied these areas.
12
The availability of large insect prey is an important factor in tricolored blackbird reproductive
success, and may influence colony site selection. Large landscapes with suitable foraging
habitat are strong drivers of colony site occupancy and abundance (NAS 2017).
Insect abundance is strongly related to biomass of herbaceous vegetation, including important
tricolored blackbird prey items like grasshoppers in grasslands (Falcone 2010). Climate,
especially drought, is thought to play a key role in abundance of grasshoppers and other insect
species in grasslands (Vose et al. 2016). The response of insect populations can differ
depending on drought severity. For example, non-severe drought and warm temperatures can
have a positive effect on grasshopper populations through increased survival and faster
population growth (Kemp and Cigliano 1994). However, extreme or prolonged drought can
negatively affect grasshopper populations through desiccation of eggs or through decreased
biomass of primary producer food sources (i.e., grasses and forbs) (Vose et al. 2016).
Reductions in precipitation not only lead to reductions in the abundance of insects in
grasslands, but may also make insect prey less accessible through changes in behavior (e.g.,
moving underground) (Barnett and Facey 2016). Severe droughts likely have strong negative
effects on grasshoppers and insect prey in general (Kemp and Cigliano 1994, Vose et al.
2016).
The established impacts of precipitation on insect populations in grasslands, especially
grasshoppers, suggests a mechanism for drought impacts on tricolored blackbird productivity.
Research is needed that measures grasshopper and other prey abundance relative to
precipitation and primary productivity around occupied tricolored blackbird colonies, and
evaluates the effect on tricolored blackbird reproductive success.
Average annual temperatures have been rising in California in recent decades, and climate
models are in broad agreement that temperatures in California will rise significantly over the
next century (DWR 2015b). The average temperature is expected to rise by approximately
2.7°F (1.5°C) by 2050, and depending on the emissions scenario, average temperatures could
increase by 4.1-8.6°F (2.3-4.8°C) by the year 2100 (Moser et al. 2012). Summer
temperatures will rise more than winter temperatures, and the increases will be greater in
inland California. As a result, the average number of extremely hot days (at least 105°F [41°C])
per year in Sacramento is expected to increase fivefold (up to 20 days) by the middle of the
century, and may increase to as many as 50 days per year by 2100 (Moser et al. 2012).
Tricolored blackbirds have been observed to cease initiation of breeding when temperatures
exceeded 90°F (32°C), although care of existing nests continued in temperatures over 100°F
(38°C) (Hamilton et al. 1995). Extremely high temperatures have also caused colony failure.
Rising temperatures may directly affect annual tricolored blackbird productivity by truncating or
interrupting the breeding season, although more work is needed on the effect of temperature
on initiation and success of nesting attempts. Tricolored blackbirds have begun nesting earlier
in the year, perhaps in response to climate change (e.g., see Tottrup et al. 2010, Mazerolle et
al. 2011). Between 1939 and 2009, the mean date of first breeding date has shifted to occur
about 22 days earlier (M. Holyoak pers. comm.).
Along with projected negative impacts to tricolored blackbird foraging habitat due to housing
and agricultural development discussed above, the areas of California with the largest climate-
projected effects on a variety of bird species are largely concentrated within the tricolored
blackbird range in the Central Valley (Jongsomjit et al. 2013). A suite of analyses integrating
the effects of climate change and land use changes in California's rangelands concluded that
13
grassland habitat loss in California could reach 37% by the year 2100 (Byrd et al. 2015).
Thorne et al. (2016) estimated the vulnerability of California's natural communities to climate
change by examining how a range of climate change scenarios would change the spatial
distribution of those communities. Two important tricolored blackbird communities, grassland
and freshwater marsh, were projected to be among the most affected natural communities in
California, with freshwater marsh being one of only four communities receiving the highest
vulnerability rank. Under multiple emission scenarios, the regions modeled as being most
highly stressed by future climate change include much of the tricolored blackbird's core range
in the Central Valley and surrounding foothills. The extent of freshwater marsh was projected
to decrease by 71%-97% by year 2100. Of the area currently occupied by grassland in
California, 16%-48% is expected to no longer be suitable, depending on the climate change
scenario. The current level of emissions is on track with the higher-impact scenarios (Thorne et
al. 2016).
The recent severe drought in California was at least partially due to, and made more severe
by, climate change (Diffenbaugh et al. 2015). Climate change is projected to bring longer and
more severe droughts to California in the future (Diffenbaugh et al. 2015, Williams et al. 2015),
exacerbating the impacts to tricolored blackbird habitat described above. The Central Valley
may be particularly vulnerable to warming-driven drought increases in the future (Williams et
al. 2015), and water deliveries are projected to be reduced by 5.6% from 2013 to 2033 due to
climate change effects on reliability (DWR 2014). Climate change effects on water supplies
and stream flows are expected to increase competition among urban and agricultural water
users and environmental needs (Moser et al. 2012). This competition may lead to decreases in
available wetland nesting substrate provided by private and public land managers. Declines in
the availability of water for agriculture may also reduce prey populations provided by high
quality crops like alfalfa and rice.
IV. Final Determination by the Commission
The Commission has weighed and evaluated the information for and against designating
tricolored blackbird as a threatened species under CESA. This information includes scientific
and other general evidence in the Petition; the Department's Evaluation; the Department's
status review; the Department's related recommendations; written and oral comments received
from members of the public, the regulated community, various public agencies, and the
scientific community; and other evidence included in the Commission's record of proceedings.
Based upon the evidence in the record the Commission has determined that the best scientific
information available indicates that the continued existence of tricolored blackbird is in serious
danger or threatened by present or threatened modifications or destruction of the species'
habitat, predation, competition, disease, or other natural occurrences or human-related
activities, where such factors are considered individually or in combination (see generally Cal.
Code Regs., tit. 14, § 670.1, subsection (i)(1)(A); Fish & G. Code, §§ 2062, 2067).
The Commission determines that there is sufficient scientific information to indicate that
designating tricolored blackbird as a threatened species under CESA is warranted at this time
and that, with adoption and publication of these findings, tricolored blackbird for purposes of its
legal status under CESA and further proceedings under the California Administrative
Procedure Act, shall be listed as threatened.
14
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