# Endangered and Threatened Wildlife and Plants; Revised Designation of Critical Habitat for the Quino Checkerspot butterfly (Euphydryas editha quino)

> Briefs, arguments, decisions, and more.

URL: https://www.frixlaw.com/law-library/documents/fr%3AE9-13800

## Record

- **Collection:** Federal Register
- **Document type:** Rule
- **Published:** June 17, 2009
- **Citation:** 74 FR 28776

## Text

DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R8-ES-2008-0006; 92210-1117-0000-B4]
RIN 1018-AV23

Endangered and Threatened Wildlife and Plants; Revised Designation of Critical Habitat for the Quino Checkerspot butterfly (
Euphydryas editha quino
)

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Final rule.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), are designating final revised critical habitat for the Quino checkerspot butterfly (
Euphydryas editha quino
) under the Endangered Species Act of 1973, as amended (Act). Approximately 62,125 acres (ac) (25,141 hectares (ha)) of habitat in San Diego and Riverside Counties, California, are being designated as critical habitat for the Quino checkerspot butterfly. This final revised designation constitutes a reduction of approximately 109,479 ac (44,299 ha) from the 2002 designation of critical habitat for the Quino checkerspot butterfly.

DATES:

This rule becomes effective on July 17, 2009.

ADDRESSES:

The final rule, final economic analysis, and map of critical habitat will be available on the Internet at
http://www.regulations.gov
at Docket No. FWS-R8-ES-2008-0006 and
http://www.fws.gov/carlsbad/
. Supporting documentation we used in preparing this final rule will be available for public inspection, by appointment, during normal business hours, at the U.S. Fish and Wildlife Service, Carlsbad Fish and Wildlife Office, 6010 Hidden Valley Road, Suite 101, Carlsbad, CA 92011; telephone 760-431-9440; facsimile 760-431-5901.

FOR FURTHER INFORMATION CONTACT:

Field Supervisor, U.S. Fish and Wildlife Service, Carlsbad Fish and Wildlife Office (see
ADDRESSES
section). If you use a telecommunications device for the deaf (TDD), call the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Background

We intend to discuss only those topics directly relevant to the designation of critical habitat for the Quino checkerspot butterfly under the Endangered Species Act, as amended (16 U.S.C. 1531
et seq.
), in this final revised critical habitat designation. For more information on the taxonomy, biology, and ecology of the Quino checkerspot butterfly, refer to the final listing rule published in the
Federal Register
on January 16, 1997 (62 FR 2313), the original final critical habitat rule published in the
Federal Register
on April 15, 2002 (67 FR 18356); the Recovery Plan for the Quino Checkerspot Butterfly (
Euphydryas editha quino
) (Service 2003a); and the proposed revised critical habitat designation published in the
Federal Register
on January 17, 2008 (73 FR 3328).

New Information on Subspecies' Description, Life History, Ecology, Habitat, and Range

We received little new information pertaining to the description, life history, distribution, ecology, or habitat of the Quino checkerspot butterfly following the 2008 proposed rule to revise critical habitat for this subspecies. The following paragraphs discuss the new information that we received, including recent information about another host plant species brought to our attention, and clarification regarding the subspecies' likely expanded range and larval diapause. Please refer to the final listing rule published in the
Federal Register
on January 16, 1997 (62 FR 2313), and the proposed revised critical habitat designation published in the
Federal Register
on January 17, 2008 (72 FR 3328), for an in-depth discussion of the subspecies' biology.

In 2008, oviposition and larval development of the Quino checkerspot butterfly were recorded for the first time on a native host plant,
Collinsia concolor
(Chinese houses). The Quino checkerspot butterfly was observed using numerous individual
C. concolor
plants at multiple locations in Riverside County (Pratt 2008a, p. 1; 2008b, p. 1; 2008c, p. 1; 2008e, p. 1). Although
C. concolor
commonly occurs in habitats with
Plantago erecta
(erect plantain),
P. patagonica
(Patagonian plantain), and
Anterrhinum coulterianum
(Coulter's snapdragon) (Pratt 2001, pp. 42-43; Anderson 2008, pp. 2, 3), this plant is typically found on north-facing slopes in cooler and moister microclimates than where the other host plant species occur (Pratt 2001, p. 40: Pratt 2008b, p. 1). Quino checkerspot butterflies readily oviposit on
C. concolor
in captivity (Pratt 2001, p. 40). Relatively heavy but previously undocumented use of
C. concolor
at multiple high-elevation locations suggests that this host plant may become increasingly important for maintaining the Quino checkerspot butterfly population resilience as habitat conditions become warmer and drier (see below and the “Summary of Comments and Recommendations” section for additional discussion regarding climate change). If
C. concolor
is a novel host plant important for maintaining the resilience of established populations, it should also facilitate the subspecies' adaptation to environmental change that may result from climate change, including range shift (Pimm
et al
. 2001, p. 531; Thomas
et al
. 2001, pp. 577-581; Parmesan 2006, pp. 644, 645, 647). For example, increased preference for a novel host plant allowed the brown argus butterfly (
Aricia agestis
) to use habitats that were too cool for the host plants it already used, thus permitting the butterfly species to cross previously large geographic gaps in its distribution that lacked its formerly preferred host plant (Pimm
et al
. 2001, p. 531; Thomas
et al
. 2001, pp. 577-581).

Next, we did not discuss repeated diapause (the low-metabolic rate resting stage of the life cycle) in our January 17, 2008 (72 FR 3328) proposed revision to critical habitat. One peer reviewer suggested this was an important aspect of the subspecies' biology (see comment 9 below); therefore, we are adding discussion here. Diapause occurs during the larval stage, primarily during summer and fall (Service 2003a, pp. 7-8). Captive rearing and observation of Quino checkerspot butterfly larvae indicate repeated diapause is relatively common (over 50 percent likelihood for the first year; Pratt 2006, p. 10) and larvae can re-enter diapause up to three times (four diapause periods), but more than three diapause periods during an individual's life span is unusual (Pratt 2007a, pp. 10-13).

Finally, the discussion of Edith's checkerspot butterfly (
Euphydryas editha
; the Quino checkerspot butterfly is a subspecies of Edith's checkerspot) range shift in our January 17, 2008 (72 FR 33808), proposed revision to critical habitat requires clarification. Although locally adapted subspecies may shift their distribution within the middle of a greater species distribution (which appears to be occurring with the Quino checkerspot butterfly's elevation range), the northward latitudinal range expansion of subspecies of Edith's checkerspot butterfly implied by Parmesan's (1996) study does not apply to the Quino checkerspot butterfly. Because the subspecies' current northern range edge is approximately 26 miles (mi) (42 kilometers (km)) south of the historical range edge, any northward expansion of the Quino checkerspot butterfly's current range would

constitute recolonization within the subspecies' historical latitudinal range (San Bernardino and Ventura counties; see Service 2003a, pp. 1-3).

Behavior and Population Structure

The best available scientific data indicate that most Quino checkerspot butterfly populations have some degree of metapopulation structure (Service 2003a, p. 22) and display metapopulation dynamics characterized by highly variable habitat occupancy patterns and detectability, similar to most subspecies of Edith's checkerspot butterfly (Mattoni
et al
. 1997, p. 111; Service 2003a, pp. 21-27). Edith's checkerspot butterfly metapopulation structure is described by Ehrlich and Murphy (1987, p. 123) as the subdivision of a population into subpopulations that occupy clusters of habitat patches and interact extensively. Harrison
et al
. (1988, p. 360) described Edith's checkerspot butterfly metapopulation structure as: “a set of [subpopulations] that are interdependent over ecological time.” Although subpopulations within a metapopulation may change in size independently, the probability of a subpopulation existing at a given time is not independent, because they are linked by an extirpation and mutual recolonization process that occurs every 10 to 100 generations (Harrison
et al
. 1988, p. 360).

Rare high-density events and dispersal behavior are thought to be key elements of Edith's checkerspot butterfly population dynamics that structure populations. Harrison (1989, p. 1241) found that although dispersal direction from habitat patches seemed to be random in the bay checkerspot butterfly (
Euphydryas editha bayensis
), dispersing butterflies were most likely to move into habitat patches when they passed within approximately 163 feet (ft) (50 meters (m)) of those habitat patches. Dispersing bay checkerspot butterflies tended to remain in habitat patches where existing butterfly density was low (Harrison 1989, p. 1241). Bay checkerspot butterfly occupancy patterns also suggested that unoccupied habitat separated from occupied habitat by hilly terrain was less likely to be colonized than habitat separated by flat ground (Harrison 1989, p. 1241).

Harrison (1989, pp. 1241, 1242) concluded that the long-term habitat recolonization pattern of her study population was likely due to relatively large numbers of bay checkerspot butterflies having dispersed from persistent “source” subpopulations. Harrison (1989, p. 1239) found bay checkerspot butterfly habitat within 0.6 mi (1 km) of a source subpopulation is 100 percent likely to be colonized by immigrants from the source subpopulation. Harrison (1989, p. 1239) also recaptured a significant number of individuals in habitat 0.6 mi (1 km) from their release point. Over a 5-day period, 5 percent of butterflies released at a single location were recaptured in an isolated “target habitat patch” 0.6 mi (1 km) away (Harrison 1989, p. 1239). Assuming mostly random initial movement direction from the release location at such a great release distance from the recapture site (Harrison 1989, p. 1241), many individuals likely traveled similar or further distances outside the study area.

High habitat colonization rates probably only occur during rare outbreak years, when relatively high local densities combine with favorable establishment conditions in unoccupied habitat (Harrison 1989, p. 1242). These rare outbreak events are also thought to play a crucial role in Quino checkerspot butterfly metapopulation resilience and the subspecies' survival (Murphy and White 1984, p. 353; Ehrlich and Murphy 1987, p. 127). Therefore, protection and management of source subpopulations likely to provide immigrants to unoccupied habitat are required for conservation of the Quino checkerspot butterfly (Service 2003a, pp. 22, 25-26, 35, 94).

Long-distance dispersal has been documented in the Edith's checkerspot butterfly, and dispersal propensity is affected by local environmental conditions and subspecies' adaptation. White and Levin (1981, pp. 348-357) conducted the only mark-recapture movement study that included the Quino checkerspot butterfly. White and Levin (1981, pp. 348-357) studied within-habitat patch movement of the Quino and bay checkerspot butterfly subspecies in southern San Diego County (male bay checkerspots were released into Quino checkerspot butterfly habitat late in the flight season when offspring survival was not considered possible). They concluded that patterns of dispersal changed “dramatically” from year to year (White and Levin 1981, p. 348), and the Quino checkerspot butterfly was less sedentary than the more heavily studied bay checkerspot butterfly (White and Levin 1981, p. 105). Although the average mark-recapture distance traveled by a Quino checkerspot butterfly in White and Levin's (1981, p. 349) study was only 305 ft (93 m), movement records were limited to the local study area. White and Levin (1981, p. 349) stated, “It seems likely from the lower rate of return in 1972 and from the observed pattern of out-dispersal that many marked animals dispersed beyond the area covered by our efforts that year. This out-dispersal might make the value for average distance [traveled] in 1972 an underestimate of significant magnitude.” Long-distance movement in the bay checkerspot butterfly has been documented as far as 4 mi (6.4 km) (Murphy and Ehrlich 1980, p. 319) and 3.5 mi (5.6 km) (Harrison 1989, p. 1239).

The above information indicates that, although Edith's checkerspot butterflies appear to be capable of long-distance dispersal, their movement propensity is variable and driven by external environmental factors. By extension, contiguous habitat between two butterflies observed 1.2 mi (2 km) from each other is within reasonable flight distance of both individuals and should be considered part of a shared home range. Therefore, based on typical long-distance recapture records, we conclude that Quino checkerspot butterflies observed within approximately 1.2 mi (2 km) of each other in contiguous habitat belong to the same population, and contiguous habitat within at least 1.2 mi (2 km) of an observed Quino checkerspot butterfly is part of that individual's population distribution.

Delineating Population Distributions

The best scientific data available to us for use in delineating Quino checkerspot butterfly population distributions consist of geographic information system (GIS)-based habitat information, subspecies observation locations, and subspecies movement data from mark-release-recapture studies. Population-scale occupancy (a population distribution) is defined as all areas used by adults during the persistence time of a population (years to decades; Service 2003a, p. 24). Focused distribution studies over multiple years are required to quantify Quino checkerspot butterfly population distributions. Therefore, the Recovery Plan described Quino checkerspot butterfly population locations in terms of “occurrence complexes” (Service 2003a, p. 35), which were simple non-habitat-based estimators of population distributions (well-mixed or metapopulation structure) and population membership of observed butterflies. Occurrence complexes are mapped in the Recovery Plan using a 0.6-mi (1-km) movement radius from each butterfly observation and may be based on the observation of a single individual. Occurrence locations within at least 1.2 mi (2 km) of each other are considered to be part of the same occurrence complex, as these occurrences are proximal enough that

the observed butterflies were likely to have come from the same population (Service 2003a, p. 35).

Occurrence complexes may expand due to new butterfly observations, or contract due to habitat loss (for example, mapped occurrence complexes were limited by development, see Service 2003a p. 78). According to recorded Edith's checkerspot butterfly movement distances (Gilbert and Singer 1973, pp. 65, 66; Harrison
et al
. 1988, pp. 367-380; Harrison 1989, pp. 1239, 1240), occurrence complexes appropriately describe the area within which a significant proportion of the habitat patch associated with individual observed butterflies is likely to occur (see above discussion and Service 2003a, p. 35).

Some occurrence complexes were identified in the Recovery Plan (Service 2003a, p. 35) as “core.” Core occurrence complexes are those that appear to be centers of population density based on geographic size, number of reported individuals, repeated observations, and evidence of reproduction. Such population density centers are likely to contain “source” subpopulations for a Quino checkerspot butterfly metapopulation (Murphy and White 1984, p. 353; Ehrlich and Murphy 1987, p. 125; Mattoni
et al
. 1997, p. 111; Service 2003a pp. 25-26), or “source” populations for megapopulations (a group of populations also dependent on one another, but on a time scale greater than that of subpopulations; Service 2003a, pp. 21, 24, 25-26). A source subpopulation is one in which the emigration rate typically exceeds the immigration rate, and is thus a source of colonists for unoccupied habitat patches (Service 2003a, p. 166). Therefore, for the purposes of critical habitat designation, we defined a core occurrence complex as an area where at least two of the following criteria apply: (1) Surveyors reported 50 or more adults during a single survey at least once; (2) immature life stages were recorded; or (3) the geographic area within the occurrence complex (within 0.6 mi (1 km) of subspecies occurrences) is greater than 1,290 ac (522 ha; the size of the smallest Core Occurrence Complex where reproduction has been documented on multiple occasions and there are historical collection records indicating long-term resilience).

Status and Local Distribution of Populations in Riverside County

Occurrence data collected in Riverside County since publication of the Recovery Plan in 2003 resulted in expansion of all core occurrence complexes and merging of some core occurrence complexes with non-core occurrence complexes (see discussion below). In particular, occurrence data collections in Riverside County since listing (62 FR 2313; January 16, 1997) have continued almost annually to expand the known elevation limit of the subspecies' range (Pratt
et al
. 2001, pp. 169-171; Service 2003a, p. 44; Goldberg 2005, pp. 8, 9; Pratt and Pierce 2005, pp. 4-5, 11-12; Pratt 2005, p. 1; San Bernardino National Forest (SBNF) GIS database). The Bautista Road Occurrence Complex (described as non-core in the Recovery Plan) is in a relatively high-elevation valley east of Temecula and north of the community of Anza, California. Multiple new observations have occurred within and around the Bautista Road Occurrence Complex (AMEC 2004, p. 6; Mooney Jones and Stokes 2005, p. 10). Consistent with criteria outlined in the Recovery Plan (Service 2003a, p. 35) and above, we now consider the Bautista Road Occurrence Complex to be a Core Occurrence Complex.

From 2004 to 2006, multiple new occurrence locations were also reported in the community of Anza, and north and northwest of the Bautista Road Core Occurrence Complex, Pine Grove Non-core Occurrence Complex, and Lookout Mountain Non-core Occurrence Complex. These new Non-core Occurrence Complexes are: (1) Cave Rocks within the community of Anza, just north of the intersection of Bautista Road and State Route (SR) 371 (AMEC 2004, p. 9); (2) Quinn Flat located between Fobes Ranch Road and Morris Ranch Road northeast of Quinn Flat and SR 74 (Pratt and Pierce 2005, pp. 4-5, 11-12; Pratt 2005, p. 1; SBNF GIS database); (3) Horse Creek adjacent to Bautista Road, southeast of Bautista Spring (AMEC 2004, p. 6; Malisch 2006, p. 1); and (4) North Rouse Ridge located on Rouse Ridge in the hills east of Bautista Canyon, near where Bautista Road exits the foothills (Goldberg 2005, pp. 8, 9; SBNF GIS database ). None of these new observation locations met two or more of the criteria needed to categorize them as a core occurrence complex. However, these new Non-core Occurrence Complexes resulted in: (1) An increased number of known occupied areas near the community of Anza; (2) an expansion of the subspecies' known geographic range at its northeastern extreme (where it had not been previously recorded, but within historical latitudinal limits of the subspecies' distribution); and (3) an increase in the subspecies' known elevation range (Service Geographic Information Systems (GIS) database).

Recent monitoring information indicates the Tule Peak and Silverado Core Occurrence Complexes described in the Recovery Plan (Service 2003a, p. 44) are part of a single high-density population distribution supporting periodic density increases, similar to historical outbreak events (Service 2003a, p. 29), such as the 1977 outbreak in San Diego County reported by Murphy and White (1984, p. 351) (see also Ehrlich and Murphy 1987, p. 127; Carlsbad Fish and Wildlife Office (CFWO) 2004; Pratt 2004, p. 17). Occupancy in the Silverado Core Occurrence Complex was first documented in 1998 (Pratt 2001, p. 17), followed by the discovery of hundreds of Quino checkerspot adults in 2001 within the Tule Peak Core Occurrence Complex (TeraCor 2002, p. 14). Such reports of hundreds of adults in the Tule Peak Core Occurrence Complex were unprecedented since the 1970s, because, typically, five or fewer individuals are reported during project-based surveys (Service GIS database).

In 2004, following a year of above-average host plant density in the Anza area (CFWO 2004), another Quino checkerspot butterfly outbreak event occurred with even higher abundance than was reported in 2001. An estimated 500 to 1000 adult Quino checkerspot butterflies were reported from the Silverado Core Occurrence Complex in a single day in 2004 (Anderson 2007, p. 1; CFWO 2004; Pratt 2004, pp. 16, 17). Additionally, more than 30 new occurrence locations with high adult densities were reported in 2004 in the vicinity of Tule Peak Road (92 to more than 100 observations in a single day) south of the Cahuilla Band of Mission Indians of the Cahuilla Reservation, California (Cahuilla Band of Indians), and the community of Anza (Osborne 2004, pp. 1-6, 8-10; Anderson 2007, p. 5; CFWO 2004; Osborne 2007, pp. 13-16). Based on these new observations, it is appropriate to merge the Tule Peak (core), Silverado (core), and Southwest Cahuilla (non-core) occurrence complexes to form a single, expanded Tule Peak/Silverado Core Occurrence Complex. This population contains higher densities and likely produces more emigrants than any other population within the subspecies' range.

The best available scientific data (including recent outbreaks in the closest core occurrence complex) suggest the new Bautista Road Core Occurrence Complex supports ongoing range shift for the Quino checkerspot butterfly upslope in elevation, and other non-core occurrence complexes north of the community of Anza may be the result of recent colonization events.

Parmesan (1996, pp. 765-766) concluded that the average (not actual) position of known Edith's checkerspot butterfly populations had shifted north and up in elevation, likely due to a warming, drying climate (conclusion supported by the technical recovery team, Service 2003a, pp. 64, 65). Parmesan (1996, pp. 765-766) compared the distribution of the Edith's checkerspot butterfly in the early part of the 20th century to its distribution from 1994 to 1996 using historical records and field surveys. This study identified a rangewide pattern of local Edith's checkerspot butterfly extirpations and noted that 80 percent of historically recorded populations in the southern part of the range were extinct at the time of the re-census in the mid-1990s (with the majority being Quino checkerspot butterfly populations). In contrast, historically recorded Edith's checkerspot butterfly populations in the mid-latitude part of the species' range experienced only 40 percent extirpations, and the extirpation rate in the northern part was as low as 20 percent (Parmesan 1996, pp. 765-766). Fewer than 15 percent of the Edith's checkerspot butterfly extirpations occurred in the highest elevation band (above 7,874 ft (2,400 m)) (Parmesan 1996, pp. 765-766).

Parmesan (1996, pp. 765-766) concluded that this pattern of extirpation indicates contraction of the southern boundary of the Quino checkerspot butterfly's overall distribution by almost 100 mi (160 km) and a shift in the average location of an Edith's checkerspot butterfly occurrence northward by 57 mi (92 km). A parallel elevation gradient in extirpations shifted the mean location of Edith's checkerspot butterfly populations upward by 407 ft (124 m). A breakpoint in the pattern of extirpations occurred at approximately 7,874 ft (2,400 m), with about 40 percent of all populations below the breakpoint recorded as extirpated in suitable habitats, while less than 15 percent were extirpated above the breakpoint. This pattern matched trends in snowpack dynamics in the Sierra Nevada (where the high-elevation populations are found) over the same period as the butterfly study, with significant trends toward lighter snowpack and earlier melt date below 7,874 ft (2400 m), and heavier snowpack and a (non-significant) trend toward later melt date above 7,874 ft (2400 m) (Johnson
et al
. 1999, pp. 63-70). This range shift closely matched shifts in mean yearly temperature (Parmesan 1996, pp. 765-766; Karl
et al
. 1996, pp. 279-292). Parmesan's study found extirpations to be most common at lower elevations and latitudes, and the Quino checkerspot butterfly's range includes both the lower elevation and lower latitude range extremes for Edith's checkerspot butterfly. Therefore, the Quino checkerspot butterfly may be the subspecies of Edith's checkerspot experiencing the greatest effects associated with changes in climate.

Studies have demonstrated a correlation of population distribution and phenology changes with climate change for many other butterfly and insect species in California and around the world (Parmesan
et al
. 1999, p. 580; Forister and Shapiro 2003, p. 1130; Parmesan and Yohe 2003, pp. 38, 39; Karban and Strauss 2004, pp. 251-254; Thomas
et al
. 2004, pp. 146-147; Osborne and Ballmer 2006, p. 1; Parmesan 2006, pp. 646-647; Thomas
et al
. 2006, pp. 415-416). Metapopulation viability analyses of other endangered nymphalid butterfly species indicate that current climate trends pose a major threat to butterfly metapopulations by reducing butterfly growth rates and increasing subpopulation extirpation rates (Schtickzelle and Baguette 2004, p. 277; Schtickzelle
et al
. 2005, p. 89). Most recently, Preston
et al
. (2008, p. 2506) incorporated biotic interactions into niche models to predict suitable habitat for species under the range of climate conditions predicted for southern California in recent climate change models (see also Hayhoe
et al
. 2004, pp. 12422-12427; IPCC 2007, p. 9).

Preston
et al
. (2008, p. 2508) found that Quino checkerspot butterfly habitat decreased and became fragmented under altered climate conditions based on the climate-only model. For increasing temperatures and 110 percent precipitation, there was a shift in habitat to the eastern portion of the currently occupied range corresponding with an upslope movement of the species to higher elevations in adjacent mountains (Preston
et al
. 2008, p. 2508). The abiotic-biotic model (better-performing model) predicted 98 to 100 percent loss of suitable Quino checkerspot butterfly habitat when the temperature increased 1.7 and 2.8 °C (1.5 and 2.5 °F) and when the precipitation was 50 percent or 150 percent of current levels (Preston
et al
. 2008, p. 2508). An increase of less than 1 °C (1.1 °F) with no change in current precipitation resulted in no predicted habitat shift, although there was an eastward (upslope) shift within the current distributional footprint at 110 percent precipitation (Preston
et al
. 2008, p. 2508). Similar climate response patterns in modeled habitat and related and co-occurring insect species further support the validity of Parmesan's (1996, pp. 765-766) Quino checkerspot butterfly observations and conclusions (Preston
et al
. 2008, pp. 2511, 2512). Therefore, the hypothesis of range shift driven by changing climate and precipitation patterns occurring in the foothills north of the community of Anza is well supported by the best available scientific information.

Documented environmental changes that have already occurred in California (Ehrlich and Murphy 1987, p. 124; Croke
et al
. 1998, pp. 2128, 2130; Davis
et al
. 2002, p. 820; Breshears
et al
. 2005, p. 15144), future drought predictions for the state (such as Field
et al
. 1999, pp. 8-10; Brunell and Anderson 2003, p. 21; Lenihen
et al
. 2003, p. 1667; Hayhoe
et al
. 2004, p. 12422; Breshears
et al
. 2005, p. 15144; Seager
et al
. 2007, p. 1181) and North America (IPCC 2007, p. 9), and extirpation of Edith's checkerspot butterfly populations following extreme climatic events (Ehrlich
et al
. 1980, pp. 101-105; Singer and Ehrlich 1979, pp. 53-60; Singer and Thomas 1996, pp. 9-39) model and predict that prolonged drought and other environmental changes related to changing climate patterns will continue into the near future, and these changes may affect Quino checkerspot butterfly populations. Thomas
et al
. (2004, p. 147) estimated that 29 percent of species in scrublands (habitat for the Quino checkerspot butterfly) face eventual extinction, and 7 (with dispersal) to 9 (without dispersal) percent of butterfly species in Mexico will become extinct (mid-range climate predictions; Thomas
et al
. 2004, p. 146). During drought conditions in 2007, surveyors noted that, for the first time since the subspecies was listed, no Quino checkerspot butterflies were observed during Riverside County surveys or core occurrence complex monitoring (CFWO 2007). Therefore, recent subspecies field evidence corresponds with the hypothesis that changing environmental conditions throughout the subspecies' range is resulting in reduced densities at lower elevations.

Maintenance of the Tule Peak/Silverado and Bautista Road core occurrence complexes and habitat connectivity to higher elevation non-core occurrence complexes is needed to prevent an increase in the subspecies' extinction probability and support range shift resulting from environmental changes due to changing climate patterns (Service 2003a, pp. 46, 47; Osborne 2007, pp. 9-10). The Anza/Mount San Jacinto foothills area (in and adjacent to the Bautista Road Core Occurrence Complex) is proximal to what is likely the highest density

population that produces the most emigrants within the subspecies' range (Tule Peak/Silverado Core Occurrence Complex) and supports the greatest elevation gradient within the extant range of the Quino checkerspot butterfly. Regardless of range-shift dynamics, this area likely supports the most resilient populations within the subspecies' current range (see above discussion of recent observations in this area). As discussed above, evidence of range shift resulting from environmental changes due to changing climate patterns includes the following: (1) Parmesan's (1996) subspecies-specific study; (2) Preston
et al
.'s (2008, pp. 2501-2505) subspecies-specific habitat model predictions; (3) recent documented Quino checkerspot butterfly outbreak events (discussed above); (4) the complete lack of Quino checkerspot butterfly observations in Riverside County during 2007 monitoring; (5) documented drought conditions and the likelihood that recurrent drought conditions will persist into the near future (see above discussion); and (6) the discovery of new non-core occurrence complexes in the most northern, highest elevation habitat areas (see above discussion of recent observations in this area). Parmesan's (1996, pp. 765-766) range-shift statistics and Preston
et al
.'s habitat models (2008, pp. 2501-2505) predict the following Quino checkerspot butterfly population changes: (1) Declines in, and loss of, the southernmost and lowest elevation populations (lowest elevation range edge already retracted likely due to a combination of development and the 1980s drought), especially in drier areas where rainfall is most variable (such as southwest Riverside County; Anderson 2000, pp. 3, 6); (2) increases in the density in the highest elevation populations, especially in wetter areas (such as the Anza area; Service 2003a, p. 44); and (3) establishment of new populations higher in elevation where range shift is least impeded by habitat loss due to land-use changes (such as the Mount San Jacinto foothills; Service GIS database and satellite imagery).

The highest elevation core occurrence complexes (Tule Peak/Silverado and Bautista Road) also support the highest (co-occurring) diversity of host plant species (
Plantago patagonica
,
Antirrhinum coulterianum
,
Collinsia concolor
,
Cordylanthus rigidus
(rigid bird's beak), and
Castilleja exserta
(purple owl's-clover)) within the range of the Quino checkerspot butterfly, a factor known to increase population resilience (Service 2003a, p. 17) and mitigate the effects of climate extremes on Edith's checkerspot butterfly populations (Hellman 2002, p. 925). Therefore, prudent design of reserves and other managed habitats near the community of Anza, where the subspecies' range is likely expanding upslope in elevation, should include landscape connectivity to other habitat patches and ecological connectivity (habitat patches linked by dispersal areas; Service 2003a, p. 162) to accommodate such range shift (Service 2003a, p. 64).

Status and Local Distribution of Populations in San Diego County

New Quino checkerspot butterfly observations (Service GIS database) between occurrence complexes identified in the Recovery Plan have resulted in merging of the Otay Valley (core), West Otay Mountain (core), Otay Lakes (core), Proctor Valley (non-core), Dulzura (non-core), and Honey Springs (non-core) occurrence complexes into a single, expanded Otay Mountain Core Occurrence Complex. This merging of occurrence complexes in the Otay area was anticipated in the Recovery Plan, as authors noted that occupied habitat in the vicinity of Otay Lakes and Rancho Jamul appeared to be an area of key landscape connectivity for all subpopulations in southwest San Diego County (Service 2003a, pp. 53, 54).

Several widely distributed new observation locations have been reported since 2002 in central San Diego County (Dudek 2005, p. 1; Faulkner 2005, p. 1; Tierra Environmental Services 2005, p. 4), and between Interstate 8 and State Route 94 (TRC 2008, pp. 33-38) resulting in four new San Diego County non-core occurrence complexes (Fanita Ranch, Sycamore Canyon, and Mission Trails Park, and Barrett Lake). The proximity of these occurrence complexes to historical collection locations (compare above-cited documents to Service 2003a, p. 3) indicates recent detections may reflect short-term increases in population densities; however, it is not likely that increasing densities will persist, given observed and predicted environmental shifts associated with changing climate patterns (see above discussion), increasing nonnative plant invasion, and the relative isolation of these non-core occurrence complexes from core occurrence complexes. Therefore, the best available data indicate that these new observation locations may be the result of surveys in areas not previously searched and likely represent residual, relatively low-density populations experiencing a long-term trend of decreasing abundance.

Multiple new Quino checkerspot butterfly observation locations have been reported in south-central San Diego County since 2002 east of the community of Campo (Dicus 2005a, pp. 1-2; b, p. 1; PSBS 2005a, p. 18; 2005b, p. 26; O'Conner 2006, pp. 2-4). This cluster of occurrence complexes near Campo is over 7 mi (11 km) from the closest previously identified core occurrence complex near the community of Jacumba (Service 2003a, p. 52; Service GIS satellite imagery and database) and over 12 mi (19 km) from the Tecate (non-core) Occurrence Complex (Service 2003a, p. 47; Service GIS satellite imagery and database). We believe the Quino checkerspot butterfly distribution east of the community of Campo is under-documented because of: (1) The small number of surveys conducted in this area (Service survey report files); (2) the existence of contiguous habitat between observation locations (Service GIS vegetation database and satellite imagery); and (3) the presence of relatively high densities of
Antirrhinum coulterianum
and
Collinsia cocolor
host plants in occupied habitat (Bureau of Indian Affairs 1992, p. c-5; Allen and Kurnow 2005, pp. 10, 13-16; Dicus 2005a, pp. 1-2; b, p. 1; PSBS 2005a, p. 18; 2005b, p. 26; O'Conner 2006, pp. 1-4, Science Applications International Corporation 2006, pp. 33, 34, 37).

Methods used in the Recovery Plan (Service 2003a, p. 35) to determine membership of occurrence locations in an occurrence complex using the sparse available occurrence data would likely underestimate the population distribution associated with this obviously independent population near the communities of La Posta and Campo. Therefore, although not quite proximal enough to be considered a single occurrence complex based on overlapping 0.6-mi (1-km) movement distances (Service 2003a, p. 35), we consider this cluster of new observations near Campo to belong to a single new La Posta/Campo Core Occurrence Complex.

Quino checkerspot butterflies were recently observed in a new location in southeast San Diego County that resulted in expansion of the Jacumba Occurrence Complex (Essex and Osborne 2005, p. 82). Additionally, data collected from the Jacumba Occurrence Complex since publication of the Recovery Plan led us to reclassify the Jacumba complex as a core occurrence complex. The Jacumba Occurrence Complex was not classified as a core occurrence complex in the Recovery Plan (Service 2003a, p. 52) due to its relatively small geographic size.

However, adult Quino checkerspot butterflies are consistently observed in the area, even during drought years and under difficult survey conditions (high winds) (CFWO 2002-2007; Klein 2007, p. 1). An estimated 50 individuals were observed in a single day near Jacumba Peak (Pratt 2007b, p. 1). Furthermore, reproduction was documented in the Jacumba Occurrence Complex in 1998 and again in 2004 (Pratt 2007c, p. 1). Therefore, given ongoing documentation of occupancy (Service 2004, 2005, 2008), documented reproduction over multiple years (Pratt 2007c, p. 1), reported observations of large numbers of individuals (50; Pratt 2007b, p. 1), and an increased occurrence complex area (approximately 522 ac (1,290 ha)), we now consider the Jacumba Occurrence Complex to be a core occurrence complex associated with what appears to be a relatively resilient population.

The prediction that drought conditions are likely to continue into the near future (Service 2003a, pp. 63, 64; see above discussion) highlights the importance of conserving populations locally adapted to drier climates and diverse habitat types (Service 2003a, p. 76). The La Posta/Campo and Jacumba core occurrence complex habitats are warmer and drier than the Otay Mountain Core Occurrence Complex and differ substantially in other habitat characteristics (Service 2003a, pp. 36-54; O'Conner 2006, p. 4). Therefore, maintenance of these core occurrence complexes is essential for recovery and survival of the Quino checkerspot butterfly in San Diego County. These new core occurrence complexes were also the only complexes in the subspecies' southern range not affected by the 2003 and 2005 fires. Therefore, new information indicates the La Posta/Campo and Jacumba Core Occurrence Complexes contribute significantly to reducing the subspecies' extinction probability.

Previous Federal Actions

The Homebuilders Association of Northern California,
et al
., filed suit against the Service in March 2005 challenging the merits of the final critical habitat designations for several taxonomic entities, including the Quino checkerspot butterfly. A settlement was reached in March 2006 that required the Service to re-evaluate five final critical habitat designations, including the Quino checkerspot butterfly. The settlement stipulated that proposed revisions to the Quino checkerspot butterfly designation would be submitted for publication to the
Federal Register
by December 7, 2007, and final revisions would be submitted by December 7, 2008. In accordance with a court-approved amendment to the settlement agreement, dated December 5, 2007, the proposed revisions were published in the
Federal Register
on January 17, 2008 (73 FR 3328). Subsequently, a court-approved amendment to the settlement agreement dated November 6, 2008, stipulated the Service deliver the final revised critical habitat designation to the
Federal Register
by June 6, 2009. For more information on previous Federal actions concerning the Quino checkerspot butterfly, refer to the proposed revisions to critical habitat published in the
Federal Register
on January 17, 2008 (73 FR 3328).

Summary of Comments and Recommendations

We requested written comments from the public on the proposed rule to revise critical habitat for the Quino checkerspot butterfly during two comment periods. The first comment period opened with the publication of the proposed rule in the
Federal Register
on January 17, 2008 (73 FR 3328), and closed on March 17, 2008. The second comment period opened with the publication of the notice of availability of the Draft Economic Analysis (DEA) in the
Federal Register
on December 19, 2008 (73 FR 77568) and closed on January 20, 2009. During both public comment periods, we contacted appropriate Federal, State, and local agencies; scientific organizations; and other interested parties and invited them to comment on the proposed rule to revise critical habitat for this subspecies and the associated DEA. During the comment periods, we requested all interested parties submit comments or information related to the proposed revisions to critical habitat, including (but not limited to) the following: unit boundaries; species occurrence information and distribution; land use designations that may affect critical habitat; potential economic effects of the proposed designation; benefits associated with critical habitat designation; areas proposed for designation and associated rationale for the non-inclusion or considered exclusion of these areas; and methods used to designate critical habitat.

During the first comment period, we received 17 comment letters (15 letters addressing the proposed revision of critical habitat, and 2 letters from a single commenter that were not related to proposed revisions to critical habitat): two from peer reviewers, three from Federal agencies, six from representatives of five Native American tribes, and six from public organizations or individuals. During the second comment period, we received nine comments addressing the proposed critical habitat designation and the DEA. Of these latter comments, two were from peer reviewers, two from Federal agencies, two from Native American tribes, and three from public organizations or individuals. We did not receive any requests for a public hearing.

Peer Review

In accordance with our Policy for Peer Review in Endangered Species Act Activities, published on July 1, 1994 (59 FR 34270), we solicited expert opinions from 10 knowledgeable individuals with scientific expertise that included familiarity with the subspecies, the geographic region in which it occurs, and conservation biology principles. Four peer reviewers submitted responses. They provided additional information, clarifications, and suggestions that we incorporated into the rule to improve the final revised critical habitat rule.

We reviewed all comments received from the peer reviewers and the public for substantive issues and new information regarding the designation of critical habitat for the Quino checkerspot butterfly. All comments are addressed in the following summary and incorporated into the final rule as appropriate.

Peer Reviewer Comments

Comment 1
: One peer reviewer stated they had recently communicated with residents in and around the community of Anza and concluded that residents moved to this area based on an appreciation of nature and the outdoors. The peer reviewer suggested the Service should inform residents on how to improve Quino checkerspot butterfly habitat. The peer reviewer also asserted that residents of Anza are suspicious of government intervention and value their personal freedom more than endangered species preservation. The peer reviewer expressed willingness to help organize a meeting that would provide private landowners from Anza with information on how to preserve the subspecies. The peer reviewer concluded that, because of their appreciation for nature, Anza residents would be willing to improve Quino checkerspot butterfly habitat on their lands, but that willingness would be decreased by critical habitat designation; therefore, we should exclude any lands in the vicinity of Anza from our revised critical habitat designation.

Our Response
: We agree that species conservation benefits provided by landowner partnerships to conserve federally listed species may minimize the conservation benefits of designating privately owned lands as critical habitat, and we appreciate the peer reviewer's interest in participating in such an endeavor. We encourage the peer reviewer to continue to communicate and work with residents of Anza (Units 6 and 7) to conserve the Quino checkerspot butterfly, within and outside of areas that meet the definition of critical habitat. Should residents of Anza or surrounding areas be interested in developing a partnership to conserve the Quino checkerspot butterfly, Service biologists are available to participate and provide information on such partnership programs as Safe Harbor Agreements for private landowners. Safe Harbor Agreements provide assurances to landowners under the Act that no additional future regulatory restrictions will be imposed if conservation practices on their land attract or perpetuate federally listed species. At this time, there is no formal partnership between the peer reviewer, residents of Anza, or the Service to conserve the Quino checkerspot butterfly or its habitat, other than the Western Riverside County Multiple Species Habitat Conservation Plan (Western Riverside County MSHCP; Dudek and Associates, Inc. 2003), under which some areas south of the community of Anza are already excluded (see “
Application of Section 4(b)(2) - Other Relevant Impacts - Conservation Partnerships
” section below).

Comment 2
: One peer reviewer observed Quino checkerspot butterflies “by the 100s” near the community of Anza during a subspecies “outbreak.” The peer reviewer observed several unique behaviors in the Anza area in 2004 (they stated 2006 but our records indicate 2004), including a female deep within a stand of
Adenostoma sparsifolium
(redshank), likely searching for sites to deposit eggs. Despite extensive survey efforts prior to this 2004 observation, the peer reviewer had never observed Quino checkerspot butterflies in dense
A. sparsifolium
, and previously assumed the subspecies never went into such areas.

The peer reviewer asserted that Quino checkerspot butterflies move many more miles during periods of high subspecies density than observed during average density years. The peer reviewer hypothesized that, under certain environmental conditions, hormonal changes could be responsible for the behavioral changes he observed. The peer reviewer also noted that, during historical “outbreaks,” Quino checkerspot butterflies were observed in downtown San Diego. The peer reviewer hypothesized this movement behavior may be unique to the Quino checkerspot butterfly among Edith's checkerspot subspecies, and movement between populations may be important for replacing extirpated populations and maintaining gene flow between extant populations. Finally, the peer reviewer stated a lack of conserved “intermediate habitat” between populations may cause extirpation of populations and, eventually, subspecies extinction.

Our Response
: We were aware of the peer reviewers' observations and had incorporated those observations into our analysis (for example, inclusion of closed-woody canopy areas in Primary Constituent Element (PCE) 2; see “Primary Constituent Elements” section below). We appreciate the peer reviewers' insights and contributions to our knowledge of the subspecies' biology.

Although we are not aware of any recorded long-distance movements for the Quino checkerspot butterfly, the one within-habitat patch movement study completed at Otay Lakes (White and Levin 1981, pp. 350, 355) concluded that Quino checkerspot butterflies were “less sedentary” than bay checkerspot butterflies and may disperse greater distances. Plasticity and variability of movement behavior is typical among
Euphydryas
spp. (Service 2003a, pp. 10-13), as demonstrated by the historical observations of Quino checkerspot butterflies in downtown San Diego that were cited by the peer reviewer. These observations indicate that, when many individuals were dispersing during at least one unusually high-density historical event, developed areas did not prevent such movement. Therefore, because the best available scientific information supports the need for within-population movement areas, but does not support the necessity or identification of “intermediate habitat” for dispersal between populations, we included only movement areas within habitat-based population distributions in our critical habitat designation (see “Criteria Used To Identify Critical Habitat” section below).

Comment 3
: Based on personal experience maintaining captive populations, the peer reviewer asserted that Quino checkerspot butterfly populations are more susceptible to inbreeding depression than most other butterfly species. The peer reviewer stated that, when closely related Quino checkerspot butterfly individuals are bred “for some time” without out-crossing, they observe greater egg and larval mortality than generally observed in butterfly species in the family Lycaenidae (coppers and blues). The peer reviewer concluded the Service should consider assisting genetic exchange between populations that appear to be losing genetic variability, such as the small population in Unit 1 (Warm Springs Creek Core Occurrence Complex). The peer reviewer stated they suspected low genetic diversity was a primary cause of the Gavilan Hills/Lake Mathews population extirpation.

Our Response
: We recognize that the increased mortality observed during captive rearing could be indicative of inbreeding depression; however, we have no basis upon which to determine whether or not populations of the Quino checkerspot butterfly outside of a laboratory setting experience inbreeding depression. We agree with the commenter's recommendation that an evaluation of the population genetics of this butterfly could assist its recovery, and we discussed the possible effects of genetic drift and inbreeding depression in the listing rule for the Quino checkerspot butterfly (Service 1997, pp. 2319-2320). We appreciate this information; however, we do not believe it is relevant to our final revised critical habitat designation.

Comment 4
: One peer reviewer stated that populations in Units 6 and 7 near the community of Anza are “continuous and not actually separate.” The peer reviewer indicated that extensive suitable habitat exists between these two units (especially in Terwilliger Valley), which is probably occupied by the Quino checkerspot butterfly. Additionally, the peer reviewer noted there are multiple public land parcels in the area and some have extensive stands of the food plant
Antirrhinum coulterianum
.

Our Response
: While landscape connectivity does exist between Units 6 and 7 in the Anza area, and some occupied habitat exists in the area that was not included in our proposed revised critical habitat units (Cave Rocks and Cahuilla Creek non-core occurrence complexes), habitat within the community of Anza is fragmented, and large areas of landscape connectivity occur outside our mapped habitat-based population distributions (that is, not occupied). Our habitat-based population distributions are the best estimate of population occupancy based on the best available scientific data. Because the habitat-based population distributions are not continuous, we must assume the Bautista Road and Tule Peak/Silverado core occurrence complexes and the Cave Rocks and Cahuilla Creek non-core

occurrence complexes are not part of a single population. We determined that habitat captured by the core occurrence complex habitat-based population distributions in Units 6 and 7 provide the PCEs laid out in the appropriate quantity and spatial arrangement essential to the conservation of the subspecies. Our criteria used to identify critical habitat focused on core occurrence complex habitat-based population distributions designed to capture all habitats likely to support resilient metapopulations, including those likely to support local source or mainland populations (also called subpopulations) and movement areas between habitat patches required for metapopulation resilience (see Service 2003a pp. 163, 165-166 for term definitions). Finally, Terwilliger Valley is not located between Units 6 and 7, it is located east of Unit 6 (Unit 7 is north). Please see “Criteria Used To Identify Critical Habitat” section below for further discussion.

Comment 5
: Two peer reviewers stated the Bautista Road Core Occurrence Complex was probably occupied at the time of listing, but occupancy was not documented because that area was not adequately surveyed at that time. The second peer reviewer asserted that, prior to 1998, butterfly experts did not know much about habitats near the community of Anza, and all high-elevation observations were thought to be dispersing individuals because the only known primary host plant,
Plantago erecta,
did not occur above 3,000 ft (914 m) in elevation. The second peer reviewer noted that Dr. John Emmel observed a Quino checkerspot butterfly [near the community of Anza] along Bautista Road in the 1970s. The second peer reviewer also suggested that surveys be conducted in higher elevation areas where the Quino checkerspot butterfly may eventually colonize to determine if the subspecies is absent and to document possible establishment of new populations in the future. Finally, the second peer reviewer asserted that movement of this subspecies into new areas will not be easy because of inbreeding depression (see Comment 3 above), and suggested the subspecies may move by local and gradual movements and eventually expand into higher elevation sites.

Our Response
: We agree that it is possible that the Bautista Road Core Occurrence Complex was occupied at the time of listing; however, we have insufficient documentation to support that assertion. We received subsequent confirmation of Dr. Emmel's historical Quino checkerspot butterfly observation referenced by the peer reviewer. Dr. Emmel (2008, p. 1) stated that, on March 26, 1988, he observed what appeared to be a single female Quino checkerspot butterfly at the intersection of Bautista Road and Tripp Flats Road at 3,840 ft (1,170 m) elevation. Dr. Emmel (2008, p. 1) further stated that this historical observation within the Bautista Road Core Occurrence Complex may have been of a dispersing individual from a more southern population, and the subspecies may have almost exclusively used
Plantago
spp. in the 1970s and 1980s. Therefore, we are uncertain when the Bautista Road Core Occurrence Complex was initially colonized; however (as stated above in the “
Background
” section), we believe it currently provides colonists to higher elevations and, through this mechanism, likely facilitates range shift resulting from environmental changes that degrade suitable habitat conditions.

Inbreeding depression may slow colonization of new areas. However, when gene flow is restricted (for example, by mountainous terrain; Service 2003a, p. 13), local adaptation can occur quickly because peripheral populations are not swamped by genes adapted to environmental conditions specific to the range core (Zakharov and Hellman 2008, p. 199). Higher rates of local adaptation at a species' range edge may counteract any negative effects of inbreeding depression on colonization rate. Therefore, we did not base any of our conclusions on the hypothesis that inbreeding depression slows colonization of new areas in this subspecies.

Comment 6
: One peer reviewer asserted the use of host plant species other than
Plantago
spp. and
Antirrhinum coulterianum
in Riverside County should be investigated before assuming they are not used. The peer reviewer stated that the western San Diego County populations may also use many undocumented host plants, including
Castilleja affinis
(coast Indian paintbrush),
Castilleja foliolosa
(woolly paintbrush),
Collinsia heterophylla
, and
Antirrhinum nuttallianum
(Nuttall's snapdragon).

Finally, the peer reviewer expressed the opinion that
Penstemon centranthifolius
(scarlet bugler) may also be an important Quino checkerspot host plant near the community of Anza. The peer reviewer stated that they observed Quino checkerspot butterflies in early spring near the community of Anza and that subspecies' presence appears to be positively correlated with relatively heavy feeding damage on
P. centranthifolius
by an as-yet-undetected herbivore. The peer reviewer hypothesized the feeding damage on
P. centranthifolius
could be caused by late-instar Quino checkerspot butterfly larvae because they had difficulty detecting Quino checkerspot butterfly larvae on host plants other than
Plantago
spp. The peer reviewer concluded that
P. centranthifolius
might be important for post-diapause larval feeding because it is the only potential host plant species available for adult egg deposition and post-diapause larval feeding during periods of drought. Therefore, the peer reviewer believes
P. centranthifolius
may be an important food source for the Quino checkerspot butterfly larvae in high-elevation sites during drought.

Our Response
: We agree the Quino checkerspot butterfly may use different host plant species across its range. We provided a list of all host plant species where egg deposition has been documented in our “Primary Constituent Elements” section below, including
Collinsia concolor
, documented in 2008 to be used in the field by the Quino checkerspot. We appreciate information on potential use of
Penstemon centranthifolius
as a host plant; however, Quino checkerspot butterfly use of this potential hostplant species has not been documented, and any related changes to this final revised critical habitat designation would not be appropriate.

Comment 7
: One peer reviewer noted that, based on his experience,
Eriodictyon
spp. (yerba santa),
Chaenactis glabriuscula
(pinchusion flower), and
Ericameria linearifolia
(narrowleaf goldenbush) are important nectar sources for Quino checkerspot butterfly survival. The peer reviewer stated some of the nectar sources on page 3335 of the proposed revised critical habitat rule (73 FR 3328; January 17, 2008) are not important because they are rarely visited by females and, therefore, do not contribute to increased production of eggs or subspecies survival.

Our Response
: We appreciate this information based on the peer reviewer's experience and have revised our list of nectar source examples in the PCEs to include the species named by the peer reviewer. The peer reviewer did not specify which nectar sources on the existing PCE list they did not believe were important. Our list of nectar sources is not exhaustive, and nectar source importance can be site specific. Therefore, we believe our current PCE nectar source list is appropriate (see “Primary Constituent Elements” section below).

Comment 8
: One peer reviewer stated that overcollection did not play a role in

the loss of Quino checkerspot butterfly populations.

Our Response
: The listing rule (62 FR 2313; January 16, 1997) identified over-collection as a threat to the Quino checkerspot butterfly. The Service has initiated a 5-year review on this subspecies and is re-evaluating the magnitude and extent of all threats. We appreciate this information; however, we do not believe it is relevant to our final revised critical habitat designation.

Comment 9
: One peer reviewer stated that they believe all areas containing low shrubs should be included in the PCEs because diapause constitutes the majority of the Quino checkerspot butterfly's annual life cycle, and larvae diapause in low shrubs such as
Eriogonum fasciculatum
(California buckwheat).

Our Response
: This critical habitat designation includes all habitat-based population distributions associated with core occurrence complexes (see “Criteria Used To Identify Critical Habitat” section below), and the PCEs include all vegetation with an open woody canopy, including shrublands (see “Primary Constituent Elements” section below). Therefore, habitat containing low shrubs essential to the conservation of the subspecies, such as
Eriogonum fasciculatum
, is included in this final revised critical habitat designation.

Comment 10
: One peer reviewer maintained that the availability of prominent hilltops should be “weighed carefully in any decision relating to the possible exclusion of critical habitat and associated conservation plans” because the loss of such courtship areas could result in the loss of populations even if other PCEs are present in designated critical habitat.

Our Response
: This peer reviewer is apparently concerned that exclusion of areas from critical habitat will result in the loss of the excluded habitat, especially habitat containing hilltops. Section 4(b)(2) of the Act authorizes the Secretary to designate critical habitat after taking into consideration the economic impacts, national security impacts, and any other relevant impacts of specifying any particular area as critical habitat. An area may be excluded from critical habitat if it is determined that the benefits of exclusion outweigh the benefits of designating a particular area as critical habitat, unless the failure to designate will result in the extinction of the species. We believe the exclusions made in this final revised rule are legally supported under section 4(b)(2) of the Act and scientifically justified. The peer reviewer specifically commented on exclusions where conservation plans are in place. Areas excluded under section 4(b)(2) based on completed habitat conservation plans (HCPs) or other Service-approved management plans receive long-term protection and conservation; therefore, areas excluded from critical habitat designation should not result in the loss of the excluded habitat,. As discussed below, we fully considered and weighed the benefits to the conservation of the subspecies from including the specific areas we determined contain the physical and biological features essential to the conservation of the Quino checkerspot butterfly (including prominent hilltops used for mating) within the habitat conservation plan areas, in light of our determination that these areas will be adequately protected on lands covered by the Western Riverside County MSHCP and the San Diego County Multiple Species Conservation Program (MSCP), City of Chula Vista Subarea Plan (see “
Application of Section 4(b)(2) - Other Relevant Impacts - Conservation Partnerships
” section below).

Comment 11
: One peer reviewer stated, “Although annual surveys for the presence of [Quino checkerspot] butterfly adults are important * * * a population can be represented for several consecutive bad years by diapausing larval clusters that have been shown to survive for at least 4 years.” The peer reviewer added that other butterfly and moth species have adapted to drought conditions in the western United States and are capable of diapausing for up to 30 years.

Our Response
: We are aware Quino checkerspot butterflies can diapause for multiple years (Service 2003a, pp. 8-9), and under extreme drought conditions, no larvae in a surveyed area may have metamorphosed into adults. We are also aware that captive rearing and observations of the Quino checkerspot butterfly larvae indicate that repeated diapause is relatively common (over 50 percent likelihood for the first year; Pratt 2006, p. 10). Larvae can re-enter diapause up to three times (four diapause periods), but more than three diapause periods during an individual's lifespan is unusual (Pratt 2007a, pp. 10-13). Captive-rearing and field data indicate that larvae typically undergo extended diapause when environmental conditions are not favorable for growth (Pratt 2007a, pp. 10-13). Negative surveys are not considered credible if unfavorable weather, such as drought, limits Quino checkerspot butterfly detectability (Service 2002, p. 6). Therefore, we have confidence in the quality of surveys conducted by individuals with recovery permits under section 10 (a)(1)(A) of the Act and the relative rarity of spurious results. We did not base any of our criteria on negative surveys, and included contiguous habitat within 1.2 mi (2 km) of all documented observations within a core occurrence complex (see “Criteria Used To Identify Critical Habitat” section below), therefore we believe the apparent concerns of this peer reviewer have been adequately addressed in this rule.

Comment 12
: One peer reviewer suggested the analysis of Quino checkerspot butterfly nectar resources in the proposed revisions to critical habitat was not sufficient. The peer reviewer maintained that nectar plant availability can vary to a large degree among occupied areas, and the relative importance of nectar plant species will change over the flight period of the butterfly and from year-to-year. The peer reviewer emphasized that it is important to consider the contribution of nectar to increased female longevity and egg production.

Our Response
: We agree that a more detailed nectar-resource-needs analysis would be desirable. However, we are not aware of any quantitative nectar-use data specific to the Quino checkerspot butterfly that would further inform our analysis. Consequently, we determined that the peer-reviewed scientific publications that characterize Quino checkerspot butterfly nectar resources are the best scientific and commercial information available. Furthermore, variability in nectar source availability is not relevant to this final revised critical habitat designation because the PCE description relevant to nectar resources is not dependent on temporal variability (for example, many herbaceous plants are not detectable or identifiable during the fall or winter seasons).

Comment 13
: One peer reviewer (A) asserted that, although climate change may affect insect distributions globally, the hypothesis that it is affecting the Quino checkerspot butterfly is not supported by “sound” biological evidence. Peer reviewer A recommended removing the climate change discussion to save taxpayer dollars, suggesting that this modification would not affect the proposed or final revised critical habitat designation. Peer reviewer A further asserted that our suggestion that the newly identified colonies of Quino checkerspot butterflies (unspecified location, presumed north of the community of Anza) are a result of climate change is speculative. Peer reviewer A noted that Parmesan's (1996)

study did not find new northern or higher elevation populations. Additionally, the peer reviewer claimed Parmesan's (1996) range shift results were a “statistical artifact” of the apparent loss of low-lying southern populations, and that her negative occupancy data might have been the result of surveys conducted during “bad” years when all individuals were diapausing larvae.

Conversely, two other peer reviewers (B and C) expressed support for use of evidence and predictions of range shift resulting from environmental changes due to changing climate patterns to determine what lands meet the definition of critical habitat. Peer reviewer B noted that Quino checkerspot butterfly populations show dramatic changes in abundance from year to year, including responses to yearly patterns of precipitation and temperature. Peer reviewers B and C noted that, because the Edith's checkerspot species is known to respond strongly to climate, the species would also be expected to respond to climate change. Peer reviewer B further stated there is no reason to expect the Quino checkerspot butterfly to respond to ongoing climate change differently from other insects, and every reason to expect it to respond similarly to other climate-sensitive species. Peer reviewer C stated specifically, “The summary of likely impacts of climate change for the near and long-term future of the Quino checkerspot butterfly (largely on page 3332 [of the proposed revised rule]) is well thought out. I fully agree with the recommendations outlined for revision and expansion of protected areas. The recommendations represent a rational adaptation plan to allow the Quino checkerspot butterfly to persist in the face of on-going climate change which is affecting habitat suitability in the region.” Peer reviewer C further stated that shifts upslope in elevation are more probable than latitudinal shifts because the Quino checkerspot butterfly's historical range was bounded on the northern and eastern sides by desert habitat, and elevation shifts require less adaptation than latitudinal shifts.

Peer reviewer C described two possible drivers of the Quino checkerspot butterfly's upslope range shift: (1) The main host plant species may shift upslope; or (2) the subspecies could switch to other host plant species occurring higher in elevation as that habitat becomes more suitable with climate change. They noted that rapid evolution toward use of novel hosts was documented for several subspecies of Edith's checkerspot. Both peer reviewers argued that new scientific information (citing several sources) has further supported Parmesan's (1996) conclusion that the range of Edith's checkerspot butterfly has retracted at lower elevations and more southern latitudes, and is likely expanding at higher elevations and more northern latitudes.

Our Response
: As detailed below, we agree with the opinions of peer reviewers B and C. We agree with peer reviewer A that removing the issue of climate change would not affect the proposed or final revised critical habitat designation; however, we do not agree it is not a relevant criterion for inclusion in critical habitat (see “Criteria Used To Identify Critical Habitat” section below). Unit 7 is designed to capture the habitat occupied by the Quino checkerspot butterfly population that is likely one of the two most resilient in existence, and also most likely to provide colonists to higher elevation habitat in the process of range shift resulting from environmental changes due to changing climate patterns (See “
Background
” section above and “Criteria Used To Identify Critical Habitat” section below).

Furthermore, in response to Peer Reviewer A's concerns, we acknowledge that inherent uncertainty exists in all conclusions drawn exclusively from correlative ecological field studies and qualitative observations (Peet 1991, p. 605). Nonetheless, case studies in complex natural systems are a foundation of ecological science, and conclusions should be drawn from generalizations based on comparison of other systems and as much specific local information as possible (Peet 1991, p. 605). Within the context of this critical habitat designation, we considered all available data concerning the likelihood of elevation range shift in the Quino checkerspot butterfly including: (1) Well-documented loss of lower-elevation populations occurring in this species (Edith's checkerspot) rangewide, and upslope elevation range-shifts (including new higher-elevation populations) in related butterfly species around the world (Parmesan
et al
. 1999 pp. 579-583; Parmesan and Yohe 2003, pp. 37-42; Parmesan 2006, pp. 648-649); (2) significantly earlier butterfly species emergence times (Parmesan 2007, p. 1860, 1864); (3) widening phenological asynchrony between butterfly maturation and host plant availability (Parmesan 2007; pp. 1860, 1864, 1868, 1870); and (4) habitat-based model predictions of pronounced future upslope subspecies range shift resulting from environmental changes due to changing climate patterns (Preston
et al
. 2008, p. 2508). The best available scientific data indicate that the Quino checkerspot butterfly is undergoing range shift and inclusion of unoccupied habitat and non-core occurrence complexes in Unit 7 encompasses habitat that is essential for the conservation of the species in light of this documented range shift regardless of causation or correlation. However, our interpretation of the data documenting and supporting apparent range shift in the Quino checkerspot butterfly is associated with environmental changes due to changing climate patterns.

We acknowledge that Parmesan's (1996, pp. 765-766) study was restricted to known historical occupancy locations and, as a result, did not document any new higher elevation populations. However, we are not aware of any peer-reviewed or other data contradicting Parmesan's (1996) upslope range shift conclusions, and the conclusions are supported by the findings of Preston
et al
. (2008, p. 2512). The peer-reviewed scientific publications and original data we relied on in this critical habitat designation for the Quino checkerspot butterfly constitute the best available scientific or commercial data.

Recent qualitative field observations of the Quino checkerspot butterfly further support the reality of range shift associated with environmental changes due to changing climate patterns. These observations include: (1) Multiple habitat-occupancy documentations at new elevation records; (2) new early emergence records indicating an extended breeding period at higher elevations; (3) higher abundance in populations on the edge of the subspecies' upper elevational range relative to lower elevations; and (4) use of a likely novel host plant species,
Collinsia concolor,
growing in cooler, wetter micro-habitats than known preferred host plant species (see “
Background
” section above). Although new occupancy sites have also been reported at intermediate elevations, these areas were more likely to have been extirpated by the 1980s drought (and subsequently recolonized) than habitats above the subspecies' known elevation range where higher average precipitation and cooler temperatures would have made habitat more suitable. Intermediate elevation sites were also already within the subspecies' known range and, therefore, more likely to have been occupied in the past. Lepidopterists have been searching for Quino checkerspot butterflies where
C. concolor
occurs for as long as they have been collecting butterflies.
C. concolor
is common in most habitats occupied by the butterfly (see “
Background
” section above); however, no lepidopterists had

documented use of this plant by the butterfly prior to 2008. Furthermore, Dr. Gordon Pratt has been personally searching for Quino checkerspot butterfly larvae on
C. concolor
at the microhabitat scale for approximately 10 years, since 1999 or earlier (Pratt 2001; pp. 34-43, 60-61), but 2008 was the first time he was able to document use by the subspecies; therefore, it is likely this host plant was not used historically.

In summary, while acknowledging some inherent uncertainty, we believe our conclusion—that newly identified high-elevation occurrence complexes (such as Quinn Flats Non-core Occurrence Complex) are likely a result of range shift associated with environmental changes due to changing climate patterns—is based on sound scientific information. We agree with the opinion of peer reviewers B and C that our use of evidence and predictions of climate change-driven range shift in determining what lands meet the definition of critical habitat is valid. The data documenting and supporting apparent range shift in the Quino checkerspot butterfly support our inclusion of unoccupied habitat adjacent to known occupied habitat and non-core occurrence complexes in Unit 7 as essential for the conservation of this subspecies.

Comment 14
: One peer reviewer stated that our conclusion that observations in central San Diego County represent residual low-density populations with decreasing abundance is speculative. The peer reviewer maintained that the importance of these populations cannot be assessed without knowing the status of possible diapausing larval clusters in the area.

Our Response
: We did not conclude in the proposed revised rule that Quino checkerspot butterfly observations in central San Diego County represent residual low-density populations with decreasing abundance; we stated, “we cannot determine whether these new non-core occurrence complexes represent: (1) Residual, low-density populations decreasing in abundance; (2) resilient, low-density populations increasing in abundance; or (3) recent colonization events.” We then specified the most likely status is residual, low-density populations decreasing in abundance. These statements do not address apparent short-term abundance or presence trends attributable to diapausing larvae that cannot be detected. Therefore, we edited the “
Background
” section of this final rule to specify that observations in central San Diego County likely represent a long-term (not short-term) decreasing abundance trend.

Assessment of populations using direct detection of diapausing larvae is not possible. Although a preliminary study of diapause site preference was recently undertaken (Pratt 2006, pp. 1-11), field surveys for diapausing larvae are not feasible given the current biological knowledge of the subspecies.

Comment 15
: One peer reviewer (A) expressed concern that heavy use of metapopulation terminology in the proposed rule may be confusing to members of the public. Additionally, the peer reviewer said that it would be valuable to think of Quino checkerspot butterfly populations as actual populations with mostly diapausing larval clusters waiting for a good year, rather than what the peer reviewer interprets the Service describing as a hypothetical [meta]population model involving periodic extirpation of local populations. Conversely, two other peer reviewers (B and C) expressed support for the use of metapopulation ecology as a basis for determining what lands meet the definition of critical habitat. Peer reviewer A pointed out that relatively isolated habitat patches have a much lower conservation value because natural extinctions there are not likely to be “rescued” by natural recolonization. Peer reviewer A stated metapopulation ecology applies to the subfamily to which the Quino checkerspot butterfly belongs (Melitaeine butterflies) and to the subspecies, citing numerous peer-reviewed, published studies of related species. Peer reviewer A emphasized that, in the absence of direct studies of population structure in this subspecies, it would be unwise to assume metapopulation ecology does not apply to the Quino checkerspot butterfly. Peer reviewer C agreed that scientific evidence supports the conclusions that the structure of Quino checkerspot butterfly habitat is inherently patchy, and the Quino checkerspot butterfly has a slightly higher typical dispersal distance than its close relative, the bay checkerspot (
Euphydryas editha bayensis
); both are indicators of metapopulation structure.

Our Response
: We appreciate the peer reviewer's concern that use of scientific terminology associated with complex population models can be confusing. As a result, we tried to minimize the use of scientific terminology and simplified our explanations of metapopulation theory in this final revised critical habitat rule, and referred simply to “populations” wherever metapopulation structure was irrelevant (the language applied to any population structure). We did not receive any additional comments indicating that our use of metapopulation terminology was confusing or that a reader could not understand the basic model concepts.

We agree with the peer reviewers who supported the use of metapopulation dynamics in our population structure analysis. Our critical habitat units are core occurrence complex habitat-based population distributions designed to capture networks of habitat patches occupied by metapopulations. These units would also protect the next most-likely type of Quino checkerspot butterfly population—diffuse but well-mixed populations that may also have shifting densities and population “footprints” (see “
Background
” section above). Because at least some elements of metapopulation dynamics models apply to Quino checkerspot butterfly populations, the technical recovery team authors of the Recovery Plan agreed that metapopulation models should be a foundation of the recovery strategy (Service 2003a, pp. 21-31). Nevertheless, the concepts of shifting population distributions and the need to protect areas of temporarily unoccupied habitat that apply to metapopulations also apply to any large population and, therefore, also support critical habitat units based on habitat-based population distributions regardless of specific population dynamics (see “Criteria Used To Identify Critical Habitat” section below). The best available scientific data (Service 2003a, pp. 21-31) indicate that local populations within a metapopulation or similar geographically defined sections of Quino checkerspot butterfly populations are periodically extirpated, and these habitats within population distributions are generally recolonized at some future time. Therefore, our consideration of metapopulation dynamics in this critical habitat revision is appropriate.

Peer reviewer A seems to conclude that very few Quino checkerspot butterfly individuals in a population mature to adulthood during any given “flight season.” Available captive-rearing data on the Quino checkerspot butterfly's repeated diapause indicate that, in a typical year, approximately 50 percent of a given population does not return to diapause (Pratt 2006, p. 10). The best available scientific data (laboratory observations) indicate that, in a presumably a typical or average growth year, approximately half the post-diapause larvae in a Quino checkerspot butterfly population will mature to adulthood. We are not aware of any other data that contradict our conclusions regarding Quino checkerspot butterfly population dynamics.

Comment 16
: One peer reviewer stated that fritillaries (various butterflies of the family Nymphalidae, especially of the genera
Speyeria
and
Boloria,
having brownish wings marked with black or silvery spots on the underside) are no longer included in the subfamily Melitaeinae and that most recent publications place fritillaries in the subfamily Heliconiinae.

Our Response
: In the proposed revised critical habitat rule, we mentioned that fritillaries were one type of butterfly belonging to the same subfamily as the Quino checkerspot butterfly. While the information provided by the peer reviewer is appreciated, such a taxonomic change does not affect Quino checkerspot butterfly taxonomy and, therefore, does not need to be addressed in this final rule.

Comment 17
: One peer reviewer offered several technical editorial suggestions with regard to our discussion of Parmesan's (1996) study and climate change-driven range shift. The peer reviewer stated that the methods used by Parmesan (1996) were slightly different than described in the proposed revised critical habitat rule and suggested the following specific corrections. The first year of the field census was actually 1992, not 1994 as stated in the proposed revised rule. The historical records ranged from 1860 to 1982, with most dating from 1930-1975. The re-census of these records began in mid-season 1992 and continued through the April field season of 1996 (thus 1996 included the southern populations, but not those in the high-latitude and high-elevation sites in the Sierra Nevada and Canada that don't fly until July and August). The peer reviewer stated that none of Parmesan's (1996) re-censusing included wet El Niño or drought years; therefore, the skewed patterns of extirpations are not attributable to climatic or geographic bias across census years.

The peer reviewer stated that the phrase “experienced 80 percent of all recorded local extirpations” on page 3331 of the proposed revised rule is not accurate. The peer reviewer suggested replacing this phrase with: “* * * and noted that 80 percent of historically recorded populations in the southern part of the range were currently extinct at the time of the re-census in the mid-1990s, while other areas of Edith's checkerspot butterfly further north experienced only 40 percent in the mid-latitudes to as low as 20 percent extirpations along the northern range boundary, and with fewer than 15 percent extirpations in the highest elevation band (above 2,400 m).”

The peer reviewer recommended adding the documentation of upward elevational shift in Edith's checkerspot butterfly from Parmesan (1996) to the description of the northward shift in population distributions on page 3331 of the proposed revised rule. The peer reviewer suggested the following text to be inserted after the statement, “This shift in range closely matched shifts in mean yearly temperature (Parmesan 1996, pp. 765-766): A parallel elevational gradient in extirpations shifted the mean location of Edith's checkerspot butterfly populations upward by 407 ft (124 m). A breakpoint in the pattern of extirpations occurred at 7,874 ft (2,400 m), with about 40 percent of all populations below 7,874 ft (2,400 m) recorded as extirpated in otherwise suitable habitats, while less than 15 percent were extirpated above 7,874 ft (2,400 m; up to the highest known population at 11,319 ft (3,450 m)). This pattern matched trends in snowpack dynamics in the Sierra Nevada (where the high-elevation populations are found) over the same time period as the butterfly study, with significant trends toward lighter snowpack and earlier melt date below 7,874 ft (2,400 m), and heavier snowpack and a (non-significant) trend toward later melt date above 7,874 ft (2,400 m; Johnson
et al
. 1999).” Furthermore, the peer reviewer stated that Karl
et al
. 1996 should be added to the latter statement as a citation for the temperature shift over the 20th century across the Edith's checkerspot butterfly's range.

The peer reviewer suggested we add Ehrlich
et al
. 1980; Singer and Ehrlich 1979; and Singer and Thomas 1996 to the list of citations on page 3332 supporting the statement “Documentation of climate-related changes that have already occurred in California” as examples of Edith's checkerspot butterfly population extirpations following extreme climatic events.

The peer reviewer stated that, on page 3331 of the proposed revised rule, “Thomas,
et al
. 2006, pp. 146-147” should be the year 2004, and this paper is properly cited as discussing projected population extinctions and species range shifts, not observed shifts as all the other cited papers.

Our Response
: We edited the above “
Background
” section to reflect these technical corrections.

Comment 18
: One peer reviewer noted the statement “The hundreds of adults observed during surveys in the Tule Peak Core Occurrence Complex in 2001 were unprecedented” (p. 3331 of the proposed revised rule) is not accurate and cited historical precedents.

Our Response
: We agree this statement was in error. We are aware of greater magnitude historical Quino checkerspot butterfly “outbreaks” than those observed in the Tule Peak Core Occurrence Complex (see “
Background
” section above). We meant that such outbreaks were unprecedented since the 1970s, starting with the 1980s drought and subsequent subspecies decline. The paper we intended to cite was Thomas,
et al
. 2006, pp. 146-147 (not 2004). We have edited the above “
Background
” section to accurately characterize this information.

Public Comments

Comments Related To Primary Constituent Elements and Criteria Used To Identify Critical Habitat

Comment 19:
One commenter requested that we designate Wright's Field in the community of Alpine as revised critical habitat because: (1) Adult Quino checkerspot butterflies were observed for 3 years at a site within approximately 3 km (1.9 mi) of Wright's Field; (2) habitat at Wright's field appears to be “ideal;” (3) Wright's Field provides “connectivity” for core Quino checkerspot butterfly populations to the south (populations not otherwise identified by commenter); (4) designation of Wright's Field would facilitate recovery; and (5) the Quino checkerspot butterfly (not currently known from this location) could be discovered at Wright's Field.

Our Response
: We acknowledge that some areas not included in this final revised critical habitat designation may contain suitable habitat and be proximal to occupied areas. We also acknowledge that management of some habitat areas not designated or proposed as revisions to critical habitat would likely contribute to the conservation (recovery) of this subspecies. However, the Act defines critical habitat as: (1) The specific areas within the geographical area occupied by the species at the time it is listed on which are found those physical and biological features (a) essential to the conservation of the species, and (b) which may require special management considerations or protection, and (2) specific areas outside the geographical area occupied by the species at the time it is listed upon a determination by the Secretary that such areas are essential for the conservation of the species. Not all areas that may contribute to a species' recovery are necessarily essential for conservation of the species. The best available data (including the information provided by the commenter) do not demonstrate that

the Wright's Field area is essential for the conservation of the subspecies.

We delineated proposed revised critical habitat using criteria based on the conservation and biological needs of the subspecies according to the best available science. Areas proposed as critical habitat are: (1) Currently occupied, core occurrence complex habitat-based population distributions (contiguous habitat within 1.2 mi (2 km) of Quino checkerspot butterfly occurrence records); (2) consistent with recommendations in the Recovery Plan (Service 2003a, pp. 35, 165); and (3) designed to include additional habitat contiguous with the Bautista Road Core Occurrence Complex habitat-based population distribution needed to support core occurrence complex resiliency and range shift resulting from environmental changes due to changing climate patterns. These criteria determine the physical or biological features essential to the conservation of this subspecies, as identified by the PCEs in the appropriate quantity and spatial arrangement, and capture the areas outside the geographical area occupied by the Quino checkerspot butterfly at the time of listing that are essential for the conservation of the subspecies (see the “Criteria Used To Identify Critical Habitat” section below). Therefore, we believe our proposed designation and this final designation accurately describe all specific areas meeting the definition of critical habitat for the Quino checkerspot butterfly, and we did not propose Wright's Field for designation as revised critical habitat.

Comment 20
: One commenter requested increasing the extent of the proposed critical habitat designation to include all recovery units, all occurrence complexes outside of recovery units, and sufficient habitat for dispersal (Service 2003a, pp. 31, 34, 35, 71, 73-76).

Our Response
: The Recovery Plan (Service 2003a, p. 75) states “Recovery units include lands both essential and not essential to the long-term conservation of the butterfly, and comprise a variety of habitat types.” Therefore, designation of all land within all recovery units, and all occurrence complexes as revised critical habitat is not appropriate. Moreover, critical habitat designations do not signal that habitat outside of the designation is unimportant or may not contribute to recovery (see response to Comment 19 above). Occupied habitat outside the final revised critical habitat designation will continue to be subject to conservation actions implemented under section 7(a)(1) of the Act, and regulatory protections afforded by the section 7(a)(2) jeopardy standard and the prohibitions of section 9 of the Act.

According to 50 CFR 424.12(e), the Secretary shall designate as critical habitat areas outside the geographical area presently occupied by a species only when a designation limited to its present range would be inadequate to ensure conservation of the species. Accordingly, when the best scientific and commercial data available indicate that limiting designation of critical habitat to areas within the geographical area presently occupied by the species is adequate to ensure the conservation of the species, we will not designate critical habitat outside those areas. In this designation, we did include habitat in Unit 7 that is outside the geographical area currently known to be occupied by the Quino checkerspot butterfly because available data support a determination that this habitat is essential for the conservation of the subspecies. However, we are not aware of any data supporting the commenter's request to include all recovery units, all occurrence complexes outside of recovery units, and unoccupied habitat as critical habitat. For discussions of areas for movement and dispersal that meet the definition of critical habitat, see responses to comments 2 and 4 above.

Comment 21
: One commenter stated that the proposed revised rule did not consider inclusion of the higher-elevation habitat needed to accommodate the subspecies ability to respond to a changing climate in any units except Unit 7, and requested expansion of the critical habitat designation to include all “stepping stone” habitat patches that would facilitate dispersal into unoccupied habitat patches at higher elevations (cited Service 2003a, p. 65).

Our Response
: We believe our criteria capture all areas that meet the definition of critical habitat. Vegetation and host plant distribution data and new distribution information (see response to Comment 20 above) indicate the Bautista Road Core Occurrence complex is part of a greater population distribution, which also shows evidence of supporting range expansion to areas outside of this unit resulting from environmental changes due to changing climate patterns in this area. Hence, we are designating areas between occurrence complexes in Unit 7 where occupancy is expected but has not been documented, but not as stepping-stone habitat patches to facilitate dispersal into unoccupied habitat patches at higher elevations.

We are not aware of any specific data supporting the commenter's request to expand critical habitat to include all possible “stepping stone” habitat patches that would facilitate dispersal into unoccupied habitat patches at higher elevations. The recovery plan describes “stepping stone” movement areas in reference to landscape connectivity between local habitat patches within a metapopulation distribution (Service 2003a, pp. 13, 162); these movement areas were captured by proposed revised critical habitat units (see also the discussion of movement and dispersal areas in response to comments 2 and 4 above).

Comment 22
: One commenter asserted the specificity of PCEs were over-restrictive. The commenter maintained having host plant species as required PCEs creates the risk that critical habitat will not be identified when plants do not germinate under dry environmental conditions.

Our Response:
The PCEs include known nutritional and physiological requirements and sites for breeding, reproduction, and rearing of offspring. Presence of a host plant is an appropriate PCE because the Quino checkerspot butterfly requires host plants for reproduction and rearing of offspring. We list all known host plants within PCE 1(B) and 1(C). Designation of critical habitat is a regulatory process that results in hard-line boundaries, so the only lands “excluded” by text are small, developed areas such as roads and single-family homes. Regardless of regulatory implications, large numbers of host plants (usually more than one species) are required during most years to support continued occupancy. Therefore, some host plants should always be detectible in habitat supporting a core occurrence complex, even in drought years when a majority of seeds fail to germinate and most larvae return to diapause. Furthermore, areas can be determined to support PCE 1 by the presence of nectar sources alone within open woody canopy vegetation (see “Primary Constituent Elements for the Quino Checkerspot Butterfly” section below). Therefore, suitable habitat within critical habitat units should be identifiable, no matter how low densities of germinating host plants are.

Comment 23
: One commenter requested that we amend PCE 2 to include areas beyond 656 ft (200 m) of a habitat patch to facilitate movement within and among habitat patches in a metapopulation distribution. The commenter asserted that PCE 2 describes features that only allow for within-habitat patch movement of Quino checkerspot butterflies, not among-patch movement. In support of

their request, the commenter cited White and Levin's (1981, pp. 350-351) findings that adult Quino checkerspot butterfly within-patch movement often exceeded 656 ft (200 m).

Our Response
: The term “habitat patch” within the context of Quino checkerspot butterfly population dynamics and movement refers to a set of host plant “micro-patches” within the typical flight range of adult butterflies (about 160 to 660 ft (50 to 200 m)) (Service 2003a, p. 22), and all nectar sources within the same distance of these host plant “micro-patches” (Service 2003a, p. 19) in areas of contiguous, open woody canopy vegetation (Service 2003a, pp. 10-11). A habitat patch defines either the entire distribution of a “well-mixed” (non-metapopulation or typical) population, or the distribution of a subpopulation (also called a local population) within a metapopulation (Service 2003a, p. 27). We did not map habitat patches because no such detailed measurements were conducted for the Quino checkerspot butterfly. The critical habitat units in this designation were designed using the best available scientific or commercial data to capture population-scale distributions for either a metapopulation or a well-mixed population.

Areas between habitat patches occupied by subpopulations of a metapopulation within a critical habitat unit should be connected to other habitat patches by open-woody canopy areas with at least one PCE. Movement areas within population distributions are already captured by PCEs 1, 2 and 3; therefore, PCE 2 need not be amended to capture movement within habitat patches or between habitat patches occupied by subpopulations of a metapopulation (see also the discussion of movement and dispersal areas in response to comments 2 and 4 above).

The purpose of PCE 2 is to capture closed-woody canopy vegetation on the periphery of a habitat patch that is used by adults and is also likely to deter adult dispersal out of the habitat patch under typical environmental conditions (Service 2003a, p. 10). All movements recorded during White and Levin's (1981, p. 349) study occurred in contiguous, open-woody canopy areas containing host plants and nectar sources already captured by PCE 1. Therefore, areas where movement distances greater than 656 ft (200 m) were recorded by White and Levin (1981, p. 349) near Otay Lakes occurred at locations that do not need to be captured by PCE 2. Furthermore, although White and Levin (1981, pp. 350-352) did record a number of Quino checkerspot butterfly within-habitat patch movement distances greater than 656 ft (200 m), it is not appropriate to apply a study of within-habitat movement to a determination of areas required for between-patch movement.

Comment 24:
A commenter owns 10,000 ac (4,047 ha) of land near Vail Lake in Riverside County (much of which falls within proposed revised critical habitat). The commenter asserted that the proposed revisions are not valid based on a study conducted by Helix Environmental Planning that the commenter claimed showed no evidence of Quino occupancy on the commenter's land.

Our Response:
We did not receive a copy of the cited study from the commenter. However, we have a survey report in our files submitted by Helix Environmental Planning, Inc. in 2003 documenting the occurrence of adult Quino checkerspot butterfly on the commenter's Vail Lake property. Surveyors made only three visits (a protocol-level survey requires at least 5) to areas distributed over a 7,500 ac (3,035 ha) area completely surrounding Vail Lake (Helix Environmental Planning 2003, p. 1). Surveyors reported over 145 adult Quino checkerspot butterfly observations from 16 sites broadly distributed across the property (Helix Environmental Planning 2003, pp. 1-2). Surveyors also described large populations of host plants and abundant nectar sources (Helix Environmental Planning 2003, pp. 1-2). Furthermore, all areas proposed as revised critical habitat within Unit 5 (Vail Lake/Oak Mountain) are also within our core occurrence complex habitat-based population distribution (see “Criteria Used To Identify Critical Habitat” section below). Therefore, we believe the inclusion of the property in question in the proposed revised critical habitat unit is valid.

Comments Related To Habitat Conservation Plan (HCP) Exclusions

Comment 25:
One commenter stated that the designation of critical habitat on lands within the Western Riverside County MSHCP is inappropriate because these lands do not require special management considerations or protection; management and protection are already provided by the regional HCP. A second commenter asserted that all lands within the Western Riverside County MSHCP area boundary should be excluded because this regional HCP adequately conserves the Quino checkerspot butterfly. Conversely, a third commenter claimed that lands within the Western Riverside County MSHCP should not be excluded from critical habitat because habitat within the HCP boundaries meets the definition of critical habitat per
Center for Biological Diversity et al.
v.
Norton
(CV 01-409, District of Arizona, January 13, 2002), where Judge David C. Bury stated, “The fact that a habitat is already under some sort of management for its conservation is absolute proof that habitat is ‘critical.'”

Our Response
: Section 3(5)(A) provides requirements for identifying (defining) critical habitat, in part, as areas that require special management considerations or protection, while section 4(b)(2) directs the Secretary to consider the impacts of designating such areas as critical habitat and provides the Secretary with discretion to exclude particular areas if the benefits of exclusion outweigh the benefits of inclusion. In this rule, we do not state that areas do not meet the definition of critical habitat under section 3(5)(A) of the Act because they are being adequately managed. Rather, we considered the management of particular areas that do meet the definition of critical habitat in our exclusion analyses under section 4(b)(2) of the Act.

Section 4(b)(2) of the Act states that the Secretary shall designate critical habitat, and make revisions thereto, under subsection (a)(3) on the basis of the best scientific data available and after taking into consideration the economic impact, the impact to national security, and any other relevant impact, of specifying any particular area as critical habitat. In accordance with 50 CFR 424.19, in conducting an impact analysis of critical habitat, the Secretary shall identify any significant activities that would either affect an area considered for designation as critical habitat or be likely to be affected by the designation, and shall, after proposing designation of such an area, consider the probable economic and other impacts of the designation on proposed or ongoing activities. The Secretary may exclude any area from critical habitat if he determines that the benefits of such exclusion outweigh the benefits of specifying such area as part of the critical habitat, unless he determines, based on the best scientific and commercial data available, that the failure to designate such area as critical habitat will result in the extinction of the species concerned. Therefore, consistent with the Act and our implementing regulations, we must consider the relevant impacts of designating areas that meet the definition of critical habitat prior to finalizing a critical habitat designation.

After determining which areas met the definition of critical habitat for the Quino checkerspot butterfly under section 3(5)(A) of the Act, we took into consideration the economic impact, the impact on national security, and other relevant impacts of specifying any particular area as critical habitat for the Quino checkerspot butterfly. In this final designation, we recognize that designating critical habitat in areas where we have partnerships with landowners that have led to conservation or management of listed species on non-Federal lands has a relevant, perceived impact to landowners and a relevant impact to future partnerships and conservation efforts on non-Federal lands. These impacts are described in detail in the “Conservation Partnerships on Non-Federal Lands” section below. Based on these impacts, we evaluated the benefits of designating areas as critical habitat against the benefits of excluding these areas from the critical habitat designation. Please see the “
Exclusions under Section 4(b)(2) of the Act
” section of this final rule for a detailed discussion of the benefits of excluding lands covered by management plans versus the benefits of including these areas in a critical habitat designation. Upon weighing the benefits of inclusion against benefits of exclusion, we determined the benefits of excluding all lands owned by or under the jurisdiction of permittees of the Western Riverside County MSHCP in Units 1 through 6 outweigh the benefits of including these areas in the final revised critical habitat designation. Further, we determined exclusion of these areas will not result in extinction of the Quino checkerspot butterfly. Therefore, we excluded all lands owned by or under the jurisdiction of the permittees of the HCP in Units 1 through 6 from this final revised critical habitat designation (see “
Application of Section 4(b)(2) - Other Relevant Impacts - Conservation Partnerships
” section below).

At the time the Western Riverside County MSHCP permit was issued, Units 1 through 6 were known to contain core occurrence complexes, and over 90 percent of the total area of these units was already designated critical habitat; therefore, the Quino checkerspot butterfly populations within these units are addressed by this regional HCP. However, the new information regarding Quino checkerspot butterfly distribution in Unit 7 was not known at the time the HCP was developed and the permit was issued; therefore, we agree the importance of habitat in this area to the conservation of the Quino checkerspot butterfly is not addressed by the Western Riverside County MSHCP. This area was not designated as critical habitat in 2002. We now have much additional distribution information in this area and determined that designation of Unit 7 is warranted to: (1) Maintain core population resilience, (2) support subspecies range shift to higher elevation habitats due to changing climate patterns that affect the environment, and (3) educate the public about this new distributional data. Therefore, land within the Western Riverside County MSHCP plan area in Unit 7 is included in our final revised designation of critical habitat because the conservation benefits to the subspecies of inclusion of this unique unit outweigh the conservation partnership-related benefits of exclusion (see “
Application of Section 4(b)(2) - Other Relevant Impacts - Conservation Partnerships
” section below for more information).

Comment 26:
One commenter expressed concern that Federal lands within the Western Riverside County MSHCP plan area were not being considered for exclusion. The commenter further stated that any designation of critical habitat within the Western Riverside County MSHCP boundary would be a violation of the plan's associated Implementing Agreement (IA), citing language in section 6.9 of the Western Riverside County MSHCP (Dudek and Associated Inc. 2003) and section 14.10 of the IA.

Our Response
: Contrary to the commenter's assertion, section 14.10 of the IA does not preclude critical habitat designation within the plan area (Dudek and Associated Inc. 2003). Consistent with our commitment under the IA, and after public review and comment on the proposed revision to critical habitat for the Quino checkerspot butterfly, we determined through our analysis under section 4(b)(2) of the Act that the maximum extent of allowable exclusions under the Western Riverside County MSHCP was limited to the exclusion of lands owned by or under the jurisdiction of the permittees of the Western Riverside County MSHCP in Units 1 through 6.

With regard to the Federal lands within the Western Riverside County MSHCP plan area, we determined that National Forest lands contain the physical and biological features essential to the conservation of the Quino checkerspot butterfly, and therefore, meet the definition of critical habitat (see “Criteria Used To Identify Critical Habitat” section below). We acknowledge that the San Bernardino National Forest (Forest Service) has a Land Resource Management Plan (LRMP) that will benefit the Quino checkerspot butterfly and its habitat. The LRMP contains general provisions for species conservation and suggests specific management and conservation actions that will benefit this species and the physical and biological features essential to its conservation. Implementation of the LRMP should address known threats to this species on Forest Service lands. We appreciate and commend the efforts of the Forest Service to conserve federally listed species on its lands.

We considered the request from the commenter that we exclude Forest Service lands from the designation because it would unnecessarily add work in the future to determine the effect regarding critical habitat for actions on its lands and the fact that it had already completed consultation under section 7(a)(2) of the Act on an LRMP. Based on the record before us, we decided not to exclude these lands and are designating National Forest lands that meet the definition of critical habitat for the Quino checkerspot butterfly. We will continue to consider on a case-by-case basis in future critical habitat rules whether to exclude particular Federal lands from such designation when we determine that the benefits of such exclusion outweigh the benefits of their inclusion.

Comment 27
: One commenter claimed that lands within the Western Riverside County MSHCP should not be excluded from critical habitat because this regional HCP does not adequately protect the subspecies and, therefore, the benefits of inclusion outweigh the benefits of exclusion. The commenter provided specific examples of how they believe the Western Riverside County MSHCP does not adequately protect the subspecies, including: (1) Approximately 10 percent of critical habitat in the proposed revised critical habitat rule falls entirely outside any targeted reserve system (outside criteria cells); (2) conservation is not likely (“only optional”) for the 14 percent of proposed revised critical habitat that is within criteria cells but not the conceptual reserve design; (3) the Western Riverside County MSHCP is not being properly implemented; (4) the Western Riverside County MSHCP does not have adequate funding for implementation; and (5) effects of global warming on covered species was never reviewed or addressed by the Western Riverside County MSHCP.

Our Response:
When we issued the permit for the Western Riverside County MSHCP, we determined that it provides

adequate protection for the Quino checkerspot butterfly and its habitat within the plan area boundary. We are monitoring the Western Riverside County MSHCP implementation and the subspecies' status and have not altered this determination. Additionally, we have not determined the Western Riverside County MSHCP to be improperly implemented or inadequately funded. We will evaluate the information submitted by the commenter and consider it in our ongoing assessments of the Western Riverside County MSHCP, and continue to work with permittees to make sure the HCP is adequately funded. If during our ongoing assessments of the Western Riverside County MSHCP we determine the HCP does not adequately protect the subspecies, is not being properly implemented, or does not have adequate funding based on all available information, we will take appropriate action with regard to the HCP permit, and may again revise designated critical habitat, subject to available funding and other conservation priorities.

Given specific Western Riverside County MSHCP conservation actions (for example, conservation of habitat in a reserve system, maintenance of core populations, enhancement of habitat), avoidance and minimization measures, and management for the Quino checkerspot butterfly and its habitat, the additional conservation value that may be afforded through a critical habitat designation in Units 1 through 6 is minimal. Furthermore, as demonstrated by comments received from Western Riverside County MSHCP partners, designation of critical habitat would negatively impact our existing working relationships and partnerships that we have developed. The information provided by the commenter does not change our determination that the benefits of excluding lands owned by or under the jurisdiction of permittees of the Western Riverside County MSHCP in Units 1 through 6 from revised critical habitat outweigh the minimal benefits of including these lands (see “
Application of Section 4(b)(2) - Other Relevant Impacts - Conservation Partnerships
” section below for a complete discussion of this exclusion).

It is true that approximately 15 percent of critical habitat in the proposed revised critical habitat rule owned by or under the jurisdiction of the permittees of the Western Riverside County MSHCP occurs entirely outside of land targeted for reserve assembly (4,020 ac (1,627 ha), only 4 percent of entire area proposed), and effects of climate change on covered species were not specifically reviewed or addressed by the HCP. The majority of proposed revised critical habitat that is outside of criteria cells occurs in large contiguous areas within Unit 7 (approximately 3,701 ac (1,498 ha)), the remainder is in small land parcels on the periphery of Unit 2 (approximately 319 ac (129 ha)). The inclusion of Unit 7 in revised critical habitat is in part to protect habitat needed to support range shift resulting from environmental changes due to changing climate patterns. In areas outside lands targeted for reserve assembly by the Western Riverside County MSHCP, the additional conservation benefits of critical habitat designation are not minimized by the HCP in Unit 7, so the benefits of inclusion are greater than those in Units 1 through 6. Therefore, we determined the benefits of exclusion do not outweigh the benefits of inclusion in Unit 7 and did not exclude lands owned by or under the jurisdiction of permittees of the Western Riverside County MSHCP in that unit from this revised critical habitat designation (see additional discussion in the “
Application of Section 4(b)(2) - Other Relevant Impacts - Conservation Partnerships
” section below).

Comment 28
: One commenter requested that lands within the Western Riverside County MSHCP not be excluded from critical habitat based on conservation benefits. The commenter stated the Western Riverside County MSHCP permittees opposition to the designation of critical habitat suggests they believe the designation would result in a greater conservation burden on them, and therefore would result in a higher level of conservation for the subspecies than will occur under the Western Riverside County MSHCP.

Our Response:
We acknowledge that stakeholder and permittee comment letters indicate opposition to designation of lands covered by the Western Riverside County MSHCP; however, these opinions are based on perception, and as such should not be the basis for determining the conservation value of critical habitat designation (benefits of inclusion). Our analysis of the benefits of inclusion and exclusion provides a more informed measure of the benefits of critical habitat designation than permittee and stakeholder opposition. Conversely, comments received from Western Riverside County MSHCP partners do indicate designation of critical habitat would negatively affect our existing positive working relationships and partnerships, thereby discouraging future HCP participation. See response to Comment 27 above for a discussion of the benefits of inclusion of lands within the Western Riverside County MSHCP plan area in the revised critical habitat designation (see additional discussion in the “
Application of Section 4(b)(2) - Other Relevant Impacts - Conservation Partnerships
” section).

Comment 29
: One commenter believes that we should not exclude lands covered by HCPs because HCPs do not provide as much protection as critical habitat. The commenter cited Taylor
et al
. (2005) as having found that species with critical habitat are less likely to decline, and over twice as likely to recover as those without critical habitat. The commenter also cited Kareiva
et al
. (1999) as finding that most HCPs fail to adequately protect species.

Our Response
: We disagree with the commenter that HCPs provide less protection than critical habitat designation. The Western Riverside County MSHCP and Chula Vista Subarea Plan incorporate on-going management and protection for the Quino checkerspot butterfly that will benefit the long-term conservation of the subspecies. The protection and long-term management provided by these HCPs to Quino checkerspot butterfly habitat extend to private lands that otherwise lack a Federal nexus under which consultation could be triggered. These two regional HCPs provide for proactive monitoring and management of conserved lands important to the survival and recovery of the Quino checkerspot butterfly. Such conservation needs are typically not addressed through application of the statutory prohibition on destruction or adverse modification of critical habitat.

We also note that exclusions are not based on the difference between protection measures provided by critical habitat designation or HCPs in isolation, but how the redundancy of protections provided by an HCP with those provided by critical habitat designation minimizes the overall conservation value of designation, and how the remaining benefits of designation are negated by the benefits of exclusion (maintaining partnerships and fostering future HCPs). Conservation benefits provided by existing HCPs are not considered a benefit of exclusion because they would remain in place regardless of critical habitat designation; however, they do minimize the benefits of inclusion to the extent they are redundant with protection measures that would be provided by critical habitat designation.

The primary benefit of a critical habitat designation is the requirement that Federal agencies do not fund,

authorize, or carry out actions on designated lands that adversely modify or destroy critical habit

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3AE9-13800. Public record. Not legal advice.