[Federal Register: June 21, 2005 (Volume 70, Number 118)]
[Proposed Rules]               
[Page 35607-35614]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]



Fish and Wildlife Service

50 CFR Part 17

Endangered and Threatened Wildlife and Plants: 90-Day Finding on 
a Petition To List the California Spotted Owl as Threatened or 

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 90-day petition finding and initiation of status 


SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
90-day finding on a petition to list the California spotted owl (Strix 
occidentalis occidentalis) as threatened or endangered, under the 
Endangered Species Act (Act) of 1973, as amended (16 U.S.C. 1531 et 
seq.). We find that the petition presents substantial scientific or 
commercial information indicating that listing the species may be 
warranted. Therefore, we are initiating a status review of the species 
to determine if listing the species is warranted. To ensure that the 
review is comprehensive, we are soliciting scientific and commercial 
information regarding this species.

DATES: The finding announced in this document was made on June 21, 
2005. To be considered in the 12-month finding for this petition, 
comments and information must be submitted to the Service by August 22, 

ADDRESSES: Submit new information, materials, comments, or questions 
concerning this species to Field Supervisor, Sacramento Fish and 
Wildlife Office, U.S. Fish and Wildlife Service, 2800 Cottage Way, Room 
W-2605, Sacramento, California 95825, or by facsimile to 916-414-6710. 
See also the ``Public Information Solicited'' section for more 
information on submitting comments. The complete file for this finding 
is available for public inspection, by appointment, during normal 
business hours at the above address.

FOR FURTHER INFORMATION CONTACT: Arnold Roessler at the Sacramento Fish 
and Wildlife Office (see ADDRESSES section above), or at (916) 414-


Public Information Solicited

    When we make a finding that substantial information is presented to 
indicate that listing a species may be warranted, we are required to 
promptly commence a review of the status of the species. Based on 
results of the status review, we will make a 12-month finding as 
required by section 4(b)(3)(B) of the Act. To ensure that the status 
review is complete and based on the best available scientific and 
commercial data, we are soliciting information on the California 
spotted owl. We request any additional data, comments, and suggestions 
from the public, other concerned governmental agencies, Native American 
Tribes, the scientific community, industry, or any other interested 
parties concerning the status of the California spotted owl. Of 
particular interest is information pertaining to the factors the 
Service uses to determine if a species is threatened or endangered: (1) 
Present or threatened destruction, modification, or curtailment of its 
habitat or range; (2) overutilization for commercial, recreational, 
scientific, or educational purposes; (3) disease or predation; (4) 
inadequacy of existing regulatory mechanisms; and (5) other natural or 
human-caused factors affecting its continued existence. In addition, we 
request data and information regarding the changes identified in the 
``Summary of Threats Analysis'' section. Finally, if we determine that 
listing the owl is warranted, it is our intent to propose critical 
habitat to the maximum extent prudent and determinable at the time we 
would propose to list the species. Therefore, we request data and 
information on what may constitute physical or biological features 
essential to the conservation of the species, where these features are 
currently found and whether any of these areas are in need of special 
management, and whether there are areas not containing these features 
which might of themselves be essential to the conservation of the 
species. Please provide specific comments as to what, if any critical 
habitat should be proposed for designation, if the species is proposed 
for listing and why that proposed habitat meets the requirements of the 
    If you wish to comment, you may submit your comments and materials 
concerning this finding to the Field Supervisor, Sacramento Fish and 
Wildlife Office (see ADDRESSES section). Our practice is to make 
comments, including names and home addresses of respondents, available 
for public review during regular business hours. Respondents may 
request that we withhold their home address, which we will honor to the 
extent allowable by law. There also may be circumstances in which we 
would withhold a respondent's identity, as allowable by law. If you 
wish us to withhold your name and/or address, you must state this 
request prominently at the beginning of your comment. We will not 
consider anonymous comments. To the extent consistent with applicable 
law, we will make all submissions from organizations or businesses, and 
from individuals identifying themselves as representatives or officials 
of organizations or businesses, available for public inspection in 
their entirety. Comments and materials received will be available for 
public inspection, by appointment, during normal business hours at the 
above address.


    Section 4(b)(3)(A) of the Act requires that the Service make a 
finding on whether a petition to list, delist, or reclassify a species 
presents substantial scientific or commercial information indicating 
that the petitioned action may be warranted. This finding is based on 
information contained in the petition, supporting information

[[Page 35608]]

submitted with the petition, and information otherwise available in our 
files at the time we make the finding. To the maximum extent 
practicable, we are to make this finding within 90 days of our receipt 
of the petition, and publish our notice of the finding promptly in the 
Federal Register.
    Our standard for substantial scientific or commercial information 
within the Code of Federal Regulations (CFR) with regard to a 90-day 
petition finding is ``that amount of information that would lead a 
reasonable person to believe that the measure proposed in the petition 
may be warranted'' (50 CFR 424.14(b)). If we find that substantial 
scientific or commercial information was presented, we are required to 
promptly commence a review of the status of the species.
    In making this finding, we relied on information provided by the 
petitioners and otherwise available in our files at the time of the 
petition review, and evaluated that information in accordance with 50 
CFR 424.14(b). Our process of coming to a 90-day finding under section 
4(b)(3)(A) of the Act and section 424.14(b) of our regulations is 
limited to a determination of whether the information in the petition 
meets the ``substantial scientific or commercial information'' 
    Our 90-day finding considers whether the petitioners have stated a 
reasonable case that listing may be warranted. Thus, our finding 
expresses no view as to the ultimate issue of whether the species 
should be listed. We reach a conclusion on that issue only after a 
thorough review of the taxon's status. In that review, which will take 
approximately 9 more months, we will perform a rigorous, critical 
analysis of the best available commercial and scientific information. 
We will ensure that the data used to make our determination as to the 
status of the species (i.e., our 12-month finding) is consistent with 
the Act and Information Quality Act (44 U.S.C. 3504(d)(1) and 3516). 
Upon completion, our 12-month finding will be published promptly in the 
Federal Register.
    On April 3, 2000, we received a petition to list the California 
spotted owl as a threatened or endangered species submitted by the 
Center for Biological Diversity and the Sierra Nevada Forest Protection 
Campaign (Center for Biological Diversity 2000), on the behalf of 
themselves and 14 other organizations. Along with listing, the petition 
also requested the concurrent designation of critical habitat, 
emergency listing, and emergency designation of critical habitat. On 
October 12, 2000, we published a 90-day finding on that petition in the 
Federal Register (65 FR 60605). In that notice, we found that the 
petition presented substantial scientific or commercial information to 
indicate that listing the California spotted owl may be warranted, and 
we initiated a status review of the taxon. On February 14, 2003, we 
published a 12-month finding on the petition in the Federal Register 
(68 FR 7580). In that notice, we found that the petitioned action was 
not warranted because the overall magnitude of threats to the species 
did not rise to the level requiring protection under the Act.
    On May 11, 2004, the Center for Biological Diversity and five other 
groups filed a lawsuit in Federal District Court for the Northern 
District of California (Center for Biological Diversity, et al. v. 
Norton et al., No. C-04-1861) alleging that our 12-month finding 
violated the Act and the Administrative Procedure Act (5 U.S.C. 706). 
On September 1, 2004, we received an updated petition dated September 
2004 to list the California spotted owl as a threatened or endangered 
species and to designate critical habitat concurrent with listing 
based, in part, on information that was not available to us at the time 
we made our 12-month finding (Center for Biological Diversity 2004). 
The updated petition was submitted by the Center for Biological 
Diversity and the Sierra Nevada Forest Protection Campaign, acting on 
behalf of themselves and six other organizations. The submission 
clearly identified itself as a petition, and included the requisite 
identification information of the petitioners, as required in 50 CFR 
    In view of the new petition, on March 8, 2005, the District Court 
in Center for Biological Diversity v. Norton issued an Order to Show 
Cause why it should not stay the litigation pending the Service's 
action on the new petition. In response to that Order, on March 14, 
2005, we submitted a declaration to the Court stating that we could 
submit for publication in the Federal Register a 90-day finding on this 
petition by June 13, 2005, and, if we found that the information 
presented in the petition was substantial, submit for publication in 
the Federal Register a 12-month finding by March 14, 2006. On March 17, 
2005, the Court stayed the case for 90 days, directed us to report to 
the Court and the parties concerning the status of our review of the 
petition by June 13, 2005, and continued the hearing on pending cross-
motions for summary judgment to June 23, 2005. On March 25, 2005, the 
Court concurred with the parties' requests to continue the hearing date 
until June 30, 2005, and to allow the Plaintiffs and Intervenor-
Defendants (American Forest and Paper Association, California Forestry 
Association, and Sierra Pacific Industries) until June 23, 2005, to 
file any responses to our June 13, 2005, filing. This notice 
constitutes the 90-day finding for the September 1, 2004, petition.

Species Information

Description and Taxonomy

    Spotted owls (Strix occidentalis) are medium-sized, brown owls with 
brown eyes, round heads without ear tufts, white spots on the head, 
neck, back, and underparts, and white and light brown bars on the wings 
and tail. Individuals range from 41 to 48 centimeters (cm) (16 to 19 
inches (in)) in length, and have wingspans of 107 to 114 cm (42 to 45 
in) (Center for Biological Diversity 2000). Sexes cannot be 
distinguished by plumage, but can be readily identified by size and 
vocalization. Females are usually larger than males, with females 
weighing 535 to 775 grams (g) (19 to 27 ounces (oz)) and males weighing 
470 to 685 g (17 to 24 oz) (Gutierrez et al. 1995).
    The California spotted owl is one of three recognized subspecies of 
spotted owls. The California spotted owl is intermediate in color 
between the darker northern spotted owl (Strix occidentalis caurina) 
and lighter Mexican spotted owl (S. o. lucida). The size of the spots 
of the California spotted owl is also intermediate between the larger 
spots of the Mexican subspecies and the smaller spots of the northern 
subspecies. The other subspecies are listed by the Service as 
threatened. The final rule to list the northern spotted owl was 
published in the Federal Register on June 26, 1990 (55 FR 26114) and 
the final rule to list the Mexican spotted owl was published in the 
Federal Register on March 16, 1993 (58 FR 14248).

Range and Distribution

    The California spotted owl still occurs throughout its historic 
range in California, extending along the west side of the Sierra Nevada 
from Shasta County south to Tehachapi Pass, and in all major mountains 
of southern California, including the San Bernardino, San Gabriel, 
Tehachapi, north and south Santa Lucia, Santa Ana, Liebre/Sawmill, San 
Diego, San Jacinto, and Los Padres ranges (Beck and Gould 1992). In 
addition, a few sites have been found on the eastern side of the Sierra 
Nevada and in the central Coast Ranges at least as far north as 
Monterey County (Service 2002). For regulatory purposes,

[[Page 35609]]

we established the Pit River as the boundary between the northern 
spotted owl and the California spotted owl (55 FR 26114). The northern 
spotted owl ranges from southwestern British Columbia, Canada, through 
western Washington, western Oregon, and northern California south along 
the coast to San Francisco Bay (Service 1990). The range of the Mexican 
spotted owl is from southern Utah and Colorado south through Arizona 
and New Mexico, and is disjunct from the ranges of the other 
subspecies. The range is discontinuous through the Sierra Madre 
Occidental and Oriental of Mexico to the mountains at the southern end 
of the Mexican Plateau (Service 1993).
    There are no reliable total population estimates for the California 
spotted owl. The number of California spotted owl territories has been 
used as an index to illustrate the range of the species and 
jurisdictions in which it occurs. This number is actually a cumulative 
total of all sites known to be historically or currently occupied by at 
least one spotted owl. This total increases over time as spotted owls 
move to new territories and as researchers survey new areas, even 
though many territories with sufficient suitable habitat are not 
occupied at the present and some territories no longer have sufficient 
suitable habitat to support spotted owls due to logging or fires. For 
example, in the Sequoia and Kings Canyon National Parks study area, 
only 34 of 44 territories (77 percent) with a history of spotted owl 
occupancy were occupied by either spotted owl pairs (n = 32) or 
resident singles (n = 2) in 2004 (Munton in litt. 2005). And in the 
Eldorado study area, only 26 of 49 territories (53 percent) were 
occupied by spotted owl pairs (n = 25) or a single spotted owl (n = 1) 
in 2004 (Seamans in litt. 2005a). Thus, the number of territories 
should not be viewed as a population estimate for the taxon.
    The total number of California spotted owl territories known in the 
Sierra Nevada is 1,865 (Service 2002). Of these, 1,399 territories are 
in Lassen, Plumas, Tahoe, Eldorado, Stanislaus, Sierra, and Sequoia 
National Forests, and 129 territories are in Lassen, Kings Canyon, 
Sequoia, and Yosemite National Parks. Fourteen territories are on BLM 
land in the Sierra Nevada, 3 are on State parks, 1 is on California 
Department of Forestry and Fire Protection land, 4 are on California 
State Lands Commission Land, 1 is on Native American land, and 314 are 
on private lands (Service 2002).
    In southern California, the spotted owl occupies ``islands'' of 
high-elevation forests isolated by lowlands covered by chaparral, 
desert scrub, and, increasingly, human development (Noon and McKelvey 
1992, LaHaye et al. 1994). California spotted owls have been found on 
440 territories in southern California, in 15 to 20 populations 
comprised of 3 to 270 individuals and separated from each other by 10 
to 72 kilometers (km) (6 to 45 miles (mi)) (Verner et al. 1992a, 
Gutierrez 1994, LaHaye et al. 1994, Service 2002). There are 329 
territories in the Angeles, Cleveland, Los Padres, and San Bernardino 
National Forests, 2 on BLM land, 8 on State parks, 6 on Native American 
lands, and 95 on private lands. In addition, 1 territory is in Mexico 
(Service 2002).

Life History

    Spotted owls usually reach reproductive maturity at 2 years of age, 
although there are rare accounts of nesting first-year birds (Verner et 
al. 1992b). Spotted owls are monogamous, and usually pair with the same 
mate from year to year (Verner et al. 1992b). Mate constancy, however, 
may be more of an attachment to a specific home range than to a 
specific mate (Forsman et al. 1984). The breeding season of California 
spotted owls extends from mid-February to mid-September or early 
October (Verner et al. 1992b).
    Among the variety of taxa on which they prey, California spotted 
owls tend to select a few key species (Verner et al. 1992b). In the 
upper elevations of the Sierra Nevada (about 1,200 to 1,525 meters (m) 
(4,000 to 5,000 feet (ft)), the primary prey is the northern flying 
squirrel (Glaucomys sabrinus), which is most common in larger stands of 
mature forests (Verner et al. 1992b). In lower elevations of the Sierra 
Nevada and in southern California, the primary prey is the dusky-footed 
woodrat (Neotoma fuscipes) (Thrailkill and Bias 1989), which is most 
abundant in shrubby habitats and uncommon in pure conifer forests or 
forests with little shrub understory (Williams et al. 1992). Both 
flying squirrels and woodrats occur in the diets of owls in the central 
Sierra Nevada (Verner et al. 1992b). Other prey items include gophers 
(Thomomys spp.), mice (Peromyscus spp.), diurnal squirrels 
(Tamiasciurus douglasii, Sciurus griseus), ground squirrels, 
(Spermophilus beecheyi), and chipmunks (Eutamias spp.) and a variety of 
other rodents, shrews (Sorex spp.), moles (Scapanus spp.), bats (Myotis 
spp.), birds, frogs, lizards, and insects (Verner et al. 1992b, 
Gutierrez et al. 1995, Tibstra 1999). Predators and closest competitors 
to spotted owls are great horned owls (Bubo virginianus) (Forsman et 
al. 1984) and barred owls (Strix varia) (Leskiw and Gutierrez 1998, 
Hamer et al. 2001, Kelly et al. 2003).
    The elevation of known nest sites of California spotted owls ranges 
from about 305 to 2,348 m (1,000 to 7,700 ft), with approximately 86 
percent of sites occurring between 915 and 2,135 m (3,000 and 7,000 ft) 
(USFS 2001). In conifer forests, mean elevation of nest sites was 1,160 
m (5,300 ft) in the northern Sierra Nevada and 1,830 m (6,000 ft) in 
southern California (Gutierrez et al. 1992).
    Spotted owls are mostly nonmigratory, remaining within their home 
ranges year round. However, in the Sierra Nevada, some individuals 
migrate downslope from early October to mid-December and return to 
their breeding territories in late February to late March, thereby 
establishing disjunct winter home ranges below the level of heavy, 
persistent snow (Verner et al. 1992b, Laymon 1989). These seasonal 
migrations range from 15 to 58 km (9 to 36 mi) with altitudinal changes 
from approximately 500 to 1,500 m (1,640 to 4,921 ft) (Verner et al. 
1992b, Laymon 1989, Gutierrez et al. 1995).
    Spotted owls primarily disperse as juveniles (natal dispersal), but 
may also disperse as adults (breeding dispersal) if habitat within 
their home range has been degraded or if they have separated from a 
mate (Verner et al. 1992b). Natal dispersal occurs in September and 
October. Mean natal-dispersal distance of 26 owls in the Sierra 
National Forest and Sequoia National Park estimated using radio 
telemetry was 15.9 km (9.9 mi) (Tibstra 1999) and median distance of 42 
owls on the Lassen National Forest estimated using recapture data was 
25 km (16 mi) for females and 23 km (14 mi) for males (Blakesley in 
litt. 2002). Mean natal-dispersal distances of 129 owls in southern 
California estimated using recapture data were 10.1 km (6.3 mi) for 
males and 11.7 km (7.3 mi) for females (LaHaye et al. 2001).

Habitat Use and Home Range

    California spotted owls, like the other two subspecies of spotted 
owls, use or select habitats for nesting, roosting, or foraging that 
have structural components of old forests, including large-diameter 
trees that are typically greater than 61 cm (24 in) diameter at breast 
height (dbh; breast height has been standardized at 137 cm (4.5 ft) 
above the ground) (Call 1990, Gutierrez et al. 1992, Zabel et al. 1992, 
Moen and Gutierrez 1997, USFS 2001), decadent trees (trees with 
cavities, broken tops, etc.); high tree density (Laymon 1988, Call 
1990, Bias and Gutierrez 1992, Gutierrez et al. 1992, LaHaye et al. 

[[Page 35610]]

Moen and Gutierrez 1997); multi-layered canopy/complex structure (Call 
1990, Gutierrez et al. 1992, LaHaye et al. 1997, Moen and Gutierrez 
1997); high canopy cover (greater than 40 percent and mostly greater 
than 70 percent; Laymon 1988, Bias and Gutierrez 1992, LaHaye et al. 
1992, Gutierrez et al. 1992, Zabel et al. 1992, Moen and Gutierrez 
1997, North et al. 2000); snags (Laymon 1988, Call 1990, Bias and 
Gutierrez 1992, Gutierrez et al. 1992, LaHaye et al. 1997); and downed 
logs (Call 1990). The mixed-conifer forest type (sugar pine (Pinus 
lambertiana), ponderosa pine (Pinus ponderosa), white fir (Abies 
concolor), Douglas-fir (Pseudotsuga menziesii), giant sequoia 
(Sequoiadendron giganteum), incense-cedar (Calocedrus decurrens), 
California black oak (Quercus kelloggii), and red fir (Abies 
magnifica)) is the predominant type used by spotted owls in the Sierra 
Nevada. About 80 percent of known sites are found in mixed-conifer 
forest, 10 percent are in red fir forest (red and white fir, lodgepole 
pine (Pinus contorta), quaking aspen (Populus tremuloides)), 7 percent 
are in ponderosa pine/hardwood forest (ponderosa pine, interior live 
oak (Quercus wislizenii), canyon live oak (Quercus chrysolepis), black 
oak, incense-cedar, white fir, tanoak (Lithocarpus densiflorus), 
Pacific madrone (Arbutus menziesii)), and the remaining 3 percent are 
in foothill riparian/hardwood forest (cottonwood (Populus spp.), 
California sycamore (Platanus racemosa), interior live oak, Oregon ash 
(Fraxinus latifolia), California buckeye (Aesculus californica), 
ponderosa pine, Jeffrey pine (Pinus jeffreyi)) (Verner et al. 1992a, 
USFS 2001).
    Six major studies, summarized in Gutierrez et al. (1992), described 
habitat relations of California spotted owls in four study areas 
(Lassen, Tahoe, Eldorado, and Sierra) spanning the length of the Sierra 
Nevada. These studies examined spotted owl habitat use at three scales: 
landscape; home range; and nest, roost, or foraging stand. Spotted owls 
preferentially use areas with at least 70 percent canopy cover, use 
habitats with 40 to 69 percent canopy cover in proportion to their 
availability, and spend less time in areas with less than 40 percent 
canopy cover than expected if habitat were selected randomly. 
California spotted owls in the Sierra Nevada prefer stands with 
significantly greater canopy cover, total live-tree basal area, basal 
area of hardwoods and conifers, and snag basal area for nesting and 
roosting. Stands suitable for nesting and roosting have: (1) Two or 
more canopy layers; (2) dominant and codominant trees in the canopy 
averaging at least 61 cm (24 in) in dbh; (3) at least 70 percent total 
canopy cover (including the hardwood component); (4) higher than 
average levels of very large, old trees; and (5) higher-than-average 
levels of snags and downed woody material (Gutierrez et al. 1992, USFS 
    In the coast range, California spotted owls occupy redwood/
California-laurel forests, which consist of a mix of coast redwood 
(Sequoia sempervirens), California laurel (Umbellularia californica), 
tanoak, Pacific madrone, red alder (Alnus rubra), white alder (A. 
rhombifolia), coast live oak, Santa Lucia fir (Abies bracteata), and 
bigleaf maple (Acer macrophyllum) (Verner et al. 1992a). Spotted owls 
can be found at elevations below 305 m (1,000 ft) along the Monterey 
coast to approximately 2,590 m (8,500 ft) in the inland mountains 
(Stephenson and Calcarone 1999). Lower-elevation (below 915 m (3,000 
ft)) spotted owls can be found in pure oak stands and higher-elevation 
(above 1,981 m (6,500 ft)) spotted owls can be found in pure conifer 
    In southern California, spotted owls also use riparian hardwood/
hardwood forests (coast and canyon live oak, cottonwood, California 
sycamore, white alder, and California laurel), live oak/bigcone 
Douglas-fir forests (coast and canyon live oak, bigcone Douglas-fir 
(Pseudotsuga macrocarpa)), and mixed-conifer forests (Verner et al. 
1992a). Spotted owl nests at 103 sites were in areas with higher canopy 
closure (mean = 79 percent) than were 296 random sites (mean = 52 
percent), and they were in areas with more conifers at least 75 cm (29 
in) dbh, more hardwoods at least 45 cm (18 in) dbh, more broken-topped 
trees, and more snags than were random sites (LaHaye et al. 1997).
    Based on all of the above-cited studies, nesting habitat for 
California spotted owls throughout their range generally is described 
as stands with an average dominant and codominant trees greater than 61 
cm (24 in) dbh and canopy cover of greater than 70 percent. Foraging 
habitat is generally described as stands of trees of 30 cm (12 in) in 
diameter or greater, with canopy cover of 40 percent or greater.
    Spotted owl pairs have large home ranges that may overlap those of 
other spotted owls (Verner et al. 1992b). Estimates of California 
spotted owl home-range size are extremely variable. All available data 
indicate that they are smallest in habitats at relatively low 
elevations that are dominated by hardwoods, intermediate in size in 
conifer forests in the central Sierra Nevada, and largest in the true 
fir forests in the northern Sierra Nevada (Zabel et al. 1992, USFS 
2001). Based on an analysis of data from radiotelemetry studies of 
California spotted owls, mean home-range sizes of breeding-season pairs 
were estimated as 3,642 hectares (ha) (9,000 acres (ac)) in true fir 
forests on the Lassen National Forest, 1,902 ha (4,700 ac) in mixed 
conifer forests on the Tahoe and Eldorado National Forests, and 1,012 
ha (2,500 ac) in mixed conifer forests on the Sierra National Forest 
(USFS 2001). The home ranges of two pairs of radio-tagged California 
spotted owls in the San Bernardino Mountains of southern California 
were smaller than those reported for the Sierra Nevada and varied 
widely between pairs (325 to 816 ha (803 to 2,016 ac)) (Zimmerman et 
al. 2001).

Changes to Habitat

    The habitat used by California spotted owls today is comprised of 
forests that have been shaped by numerous interacting natural impacts 
such as fires and precipitation, and human impacts including fire 
suppression, timber harvest, livestock grazing, and urbanization. Fire 
intervals are estimated to have been 5 to 30 years in the mixed-conifer 
forests of the Sierra before European arrival (Weatherspoon et al. 
1992), and moderate-intensity fires (fires that were hot enough to scar 
but not kill most mature trees) historically occurred every 15 to 30 
years in the forests of southern California (Stephenson and Calcarone 
1999). Suppression of wildland fires, established in California as 
State and Federal policy by the early 20th century, virtually 
eliminated forest fires. For example, it is estimated that only 269 ha 
(664 acres) burn annually in the 237,146-ha (586,000-acre) Eldorado 
National Forest, whereas approximately 11,736 ha (29,000 acres) burned 
annually there before European arrival (Weatherspoon et al. 1992). Due 
to the lack of frequent fires, many forested areas have grown dense 
layers of understory trees and have accumulated large amounts of woody 
debris on the forest floor, thereby increasing the chances of high-
intensity, stand-replacing crown fires in the Sierras and in the 
mountains of southern California (Kilgore and Taylor 1979, McKelvey and 
Weatherspoon 1992, Weatherspoon et al. 1992, Stephenson and Calcarone 
1999). In addition, in areas throughout the range of the California 
spotted owl, trees that are dead or dying due to disease add to the 
already dense accumulations of woody debris. This abundance of fuels 
led to the recent

[[Page 35611]]

large-scale fires in spotted owl habitat in southern California. One of 
the challenges in assessing the effects of fire management of 
California spotted owl habitat is the need to weigh the long-term 
benefits of the reduction of risk of catastrophic fires against any 
potential short-term effects on the quality or quantity of spotted owl 
    Timber harvest is another obvious impact to California spotted owl 
habitat (Guti[eacute]rrez 1994, Verner et al. 1992a). In the Sierra 
Nevada, timber harvest steadily intensified from the railroad building 
and mining eras of the 1800s until the 1950s, then remained at 
relatively high levels through the 1980s (McKelvey and Johnston 1992). 
Since the late 1980s, the volume of timber harvested in the Sierra 
Nevada has declined substantially. Verner et al. (1992a) discussed five 
major factors of concern for California spotted owl habitat that have 
resulted from historical timber-harvest strategies: (1) Decline in the 
abundance of very large, old trees; (2) decline in snag density; (3) 
decline in large-diameter logs; (4) disturbance or removal of duff and 
topsoil layers; and (5) change in the composition of tree species. Of 
these concerns, they believed significant changes in diameter 
distributions of trees in the Sierra Nevada and rapid reductions in the 
distribution and abundance of large, old, and decadent trees posed the 
greatest threats to the California spotted owl. Thus, extensive 
commercial harvest in the past of large old trees in late-successional 
forests directly affected the key structural components of California 
spotted owl habitat. Changes in California's Forest Practices Act, as 
well as changes in the management of Federal forest lands have largely 
eliminated past practices. The difficulty is that it will take many 
decades for these forests to regain these late-successional components 
and, in the interim, forests must be managed without modifying 
remaining suitable habitat to the degree that we negatively affect 
spotted owl numbers or distribution.

Threats Analysis

    Section 4 of the Act and its implementing regulations (50 CFR 424) 
set forth the procedures for adding species to the Federal list of 
endangered and threatened species. A species may be determined to be an 
endangered or threatened species due to one or more of the five factors 
described in section 4(a)(1) of the Act: (A) Present or threatened 
destruction, modification, or curtailment of habitat or range; (B) 
overutilization for commercial, recreational, scientific, or 
educational purposes; (C) disease or predation; (D) inadequacy of 
existing regulatory mechanisms; or (E) other natural or manmade factors 
affecting its continued existence. In making this finding, we evaluated 
whether threats to the California spotted owl as presented in the 
petition and other information available to us may pose a concern with 
respect to the taxon's survival such that listing under the Act may be 
warranted. Our evaluation of these threats, based on information 
provided in the petition and available in our files, is presented 

A. Present or Threatened Destruction, Modification, or Curtailment of 
the Species' Habitat or Range

    The petition states that more than 100 years of logging in the 
Sierra Nevada Mountains resulted in loss of spotted owl habitat, which 
negatively affects spotted owl numbers and distribution, and in 
fragmentation of habitat, which negatively affects spotted owl 
dispersal. The petition cites the 10 areas of concern (AOCs) in the 
Sierra Nevada described in Beck and Gould (1992), and then explicitly 
modifies them into nine AOCs. These AOCs, which comprise less than one-
half of the taxon's range, are of concern because they are bottlenecks 
or gaps in spotted owl distributions, support locally isolated 
populations, contain highly fragmented habitat, or have low spotted owl 
density. The petition contends that logging as prescribed in the Sierra 
Nevada Forest Plan Amendment (SNFPA) (USFS 2004a), the Herger Feinstein 
Quincy Library Group Forest Recovery Act Pilot Project (HFQLG Pilot 
Project), and on private lands threatens to further degrade and destroy 
spotted owl habitat, resulting in continued declines in numbers of 
spotted owls.
    The petition cites the recently published meta-analysis of 
population dynamics of California spotted owls (Franklin et al. 2004) 
as evidence that spotted owl populations are declining and that 
management of forests may be a cause of these declines. This meta-
analysis analyzed demographic data of spotted owls on the Lassen (1990 
to 2000), Eldorado (1986 to 2000), Sierra (1990 to 2000), and San 
Bernardino 1987 to 1998) National Forests and in Sequoia and Kings 
Canyon National Parks (1990 to 2000). The petition reports that the 
pooled estimate for adult apparent survival for the four National 
Forests (0.819) was lower than that from Sequoia and Kings Canyon 
National Parks (0.877) and that from 15 northern spotted owl studies 
(0.850). The petition states that estimates for [lambda] (lambda, the 
finite rate of population change, where [lambda] <  1.0 indicates a 
declining population and [lambda] > 1.0 an increasing population) for 
four of the five study areas (the exception was Eldorado) were less 
than 1.0, but that none of the estimates for [lambda] was different 
from [lambda] = 1.0 given the 95-percent statistical confidence 
intervals. In addition to citing the meta-analysis, the petition 
references site-specific studies (e.g., Blakesley et al. 2001, Seamans 
et al. 2001) that indicate negative population trends. The petition 
claims that we did not adequately address these reported declines in 
our 12-month finding (68 FR 7580) due to our heavy reliance on 
[lambda], 95-percent confidence intervals, and scientific uncertainty.
    The petition also notes that recent fires, as well as human 
activities including urban development, livestock grazing, mining, 
recreation, and road construction, have contributed to past and present 
loss and degradation of spotted owl habitat.

Evaluation of Information in the Petition and Other Information in our 

    As described above in ``Historic Habitat Loss,'' spotted owl 
habitat has been degraded or removed due to many human activities over 
approximately the past 150 years. Beck and Gould (1992), Verner et al. 
(1992a), USFS (2001), USFS (2004a), and the petitioners agree that the 
risk associated with management within the AOCs in the Sierra Nevada is 
higher than that in other areas. USFS (2004a) explicitly states that 
the revised SNFPA increases the risk of continued declines in spotted 
owl density within the AOCs. In our 2003 12-month finding (68 FR 7580), 
we analyzed the effects to spotted owl habitat from timber harvest on 
Federal, State, and private lands relative to the Federal and State 
regulations in effect at that time. After publication of our 12-month 
finding, the Forest Service issued a revised SNFPA (USFS 2004a) that 
allows for full implementation of the HFQLG Pilot Project, and for more 
flexibility in locating and implementing effective fire-fuels 
treatments than did the 2001 SNFPA (USFS 2001). We have not yet 
completed a detailed analysis of how these differences will affect the 
California spotted owl. Although not mentioned in the petition, we are 
aware that recent changes in the Fuel Hazard Reduction Emergency Rule 
and Variable Retention Rule of the California State Forest Practices 
Code will influence the management of California spotted owl habitat, 
but we have not yet analyzed exactly how they will do so. As noted 
above, issues raised by the petitioners regarding changes in the SNFPA 

[[Page 35612]]

2001 to 2004 and information in our files concerning changes to the 
California State Forest Practices Code justify further analysis in a 
status review and 12-month finding due to the certainties related to 
the relative risks associated with fire management or lack thereof and 
spotted owl habitat.
    When we published our 2003 12-month finding (68 FR 7580), the meta-
analysis (Franklin et al. 2004) was in draft form. At that time, the 
final, published version was not available. A detailed analysis of any 
changes made by the authors, including how such changes may alter our 
2003 analysis, is appropriately conducted as part of a status review 
and 12-month finding process.
    We agree with the petition that recent fires, urban development, 
livestock grazing, mining, recreation, and road construction have 
contributed to past and, to a lesser extent, present loss and 
degradation of California spotted owl habitat. Of these impacts, fire 
and its effects are of particular concern. For example, information in 
our files indicates that five spotted owl territories in the San Diego 
Ranges were completely burned in 2003, and nine territories in the San 
Gabriel Mountains were burned so heavily in 2002 and 2003 that it is 
doubtful that they can support spotted owls at this time (USFS 2004a, 
Loe in litt. 2005). The impacts of these recent fires and anticipated 
future fires in spotted owl habitat justify further analysis. Based on 
the information presented in the petition and information available in 
our files, we find that substantial information indicates that there is 
a threat of destruction, modification, or curtailment of the species' 
habitat or range due to fires.
    To summarize Factor A, a number of changes have taken place during 
the past 2 years that may affect California spotted owl habitat and 
effect corresponding changes in California spotted owl populations. 
These include: revisions to the 2001 SNFPA (USFS 2001) in the 2004 
SNFPA (USFS 2004a); revisions to the California State Forest Practices 
Code; impacts of recent fires and anticipated future fires in spotted 
owl habitat; and how these threats affect our interpretation and 
application of the results of the final report on the meta-analysis of 
the population dynamics of the California spotted owl (Franklin et al. 
2004). We find that these changes constitute substantial information 
that the threatened destruction, modification, or curtailment of the 
species' habitat or range may be a factor that threatens the continued 
existence of the taxon, and thus that the petitioned action may be 

B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    The petition does not present any threats relative to factor B, nor 
is there any new information available in our files.

C. Disease or Predation

    The petition states that West Nile Virus (WNV) presents a serious 
potential threat to California spotted owls, and recommends that its 
effects on spotted owls be monitored closely. As stated in the 
petition, WNV was first detected in the United States in 1999 in New 
York, and has quickly spread to the western United States. The petition 
states that WNV has not been detected thus far in a wild spotted owl, 
but that an infected, captive spotted owl suffered mortality.
    The petition cites a personal communication (Peery in litt. 1999) 
in support of its claims that, because great horned owls and red-tailed 
hawks (Buteo jamaicensis) tend to forage in open areas and because 
great horned owls are known predators of spotted owls (Forsman et al. 
1984), the reduction of canopy cover and creation of breaks in the 
canopy due to logging may increase predation of spotted owls.

Evaluation of Information in the Petition and Other Information in our 

    As stated in the petition, WNV has not yet been detected in a wild 
spotted owl. Although not mentioned in the petition, we are aware that, 
in 2004, researchers in California took blood samples and oral swabs 
from captured spotted owls to test for the presence of WNV and WNV 
antibodies. One team tested for WNV in California spotted owls in the 
Eldorado study area and in northern spotted owls of northern California 
in the Willow Creek, Green Diamond Resource Company, and Hoopa Tribal 
Lands study areas (n = 119) (Franklin in litt. 2004, 2005, 
Guti[eacute]rrez in litt. 2005). Another team took blood samples from 
California spotted owls in Plumas and Lassen National Forests (n = 68) 
(Keane 2005). None of the spotted owls tested positive for WNV exposure 
(Keane 2005, Franklin in litt. 2005, Guti[eacute]rrez in litt. 2005). 
In addition, none of the small mammals (e.g., mice, northern flying 
squirrels, dusky-footed woodrats) sampled in two study areas (Willow 
Creek and Eldorado) (n = 251) tested positive for WNV (Franklin in 
litt. 2005). Neither the petition nor information available in our 
files presents substantial information that WNV may threaten the 
continued existence of the California spotted owl.
    The petition does not present any scientific information that 
supports the idea that logging increases predation of spotted owls by 
great horned owls or red-tailed hawks, and we are unaware of any such 
information. Therefore, neither the petition nor information available 
in our files presents substantial information that predation may 
threaten the continued existence of the California spotted owl.

D. Inadequacy of Existing Regulatory Mechanisms

    The petition contends that the SNFPA (USFS 2004a) does not 
adequately protect large trees, high canopy closure, multiple-canopy 
layers, snags, and downed wood, that it allows for fuels treatment in 
more Protected Activity Centers (PACs) than the 2001 Sierra Nevada 
Forest Plan (USFS 2001), and that it does not provide limits on the 
proportion of areas that can be degraded through logging. The 
appendices to the petition include letters and declarations from 
spotted owl biologists (e.g., J. Blakesley, B. Noon, Z. Peery, and J. 
Verner) in support of this contention. The petition also contends that 
the California State Forest Practices Code provides almost no specific 
protections for the spotted owl or its habitat.

Evaluation of Information in the Petition and Other Information in our 

    As stated above in factor A, we analyzed the effects to spotted owl 
habitat from timber harvest on Federal, State, and private lands in our 
2003 12-month finding (68 FR 7580) relative to the Federal and State 
regulations in effect at that time, and we are aware that recent 
changes to the 2001 SNFPA (USFS 2001) and to the California State 
Forest Practices Code (the Fuel Hazard Reduction Emergency Rule and 
Variable Retention Rule of the Code) may affect California spotted owl 
habitat. Accordingly, the petition and information available in our 
files present substantial scientific information that due to the change 
in regulatory mechanisms since our last status review, existing 
regulatory mechanisms may be inadequate to ensure the continued 
existence of the California spotted owl, and thus that the petitioned 
action may be warranted.

[[Page 35613]]

E. Other Natural or Manmade Factors Affecting the Species' Continued 

    The petition states that short-term fluctuations in climate 
negatively affect reproduction in spotted owls and may increase the 
risk of extinction of California spotted owls. It states that logging, 
historic livestock grazing, and fire suppression have increased the 
risk of stand-replacing fires. The petition also presents concern that 
threats from hybridization and site competition with the barred owl 
have increased in recent years due to the barred owl's recent expansion 
farther into the range of the California spotted owl.

Evaluation of Information in the Petition and Other Information in Our 

    As stated in the petition, variation in survival of California 
spotted owls has been shown to be based on habitat variation, whereas 
variation in reproductive output was based equally on variations in 
habitat and climate (Franklin et al. 2000). Although not stated in the 
petition, research shows that weather conditions explained all or most 
of the temporal variations in fecundity observed in California spotted 
owls (North et al. 2000, Franklin et al. 2004, LaHaye et al. 2004) and 
northern spotted owls in northwestern California (Franklin et al. 
2000), and that spotted owls compensate for this highly variable annual 
reproduction with high annual adult survival (Franklin et al. 2000). 
Researchers also state that the long-term effects of variations in 
reproductive success of spotted owls in California due to climate are 
unknown, and will require decades of study (Franklin et al. 2000, North 
et al. 2000, Franklin et al. 2004, LaHaye et al. 2004). Therefore, 
neither the petition nor our files contain substantial information that 
indicates that climate is a threat to the continued existence of the 
California spotted owl at this time.
    Various human activities, especially fire suppression, have 
resulted in more fire-prone forests, as discussed in our 2003 12-month 
finding (68 FR 7580). Management of this threat is the purpose of the 
SNFPA (USFS 2004a), and, as described in factors A and D above, changes 
to the 2001 SNFPA and California State Forest Practices Code will be 
addressed in our 12-month finding. In addition, as described in factor 
A above, anticipated effects due to fires will be addressed in our 12-
month finding.
    As stated in the petition, barred owls hybridize with spotted owls. 
However, information in our files indicates that, although barred owls 
and spotted owls occasionally hybridize (e.g., Hamer et al. 1994, Kelly 
and Forsman 2004), this behavior is an ``inconsequential'' phenomenon 
that takes place mostly when barred owls move into new areas, and 
declines as barred owls become more numerous and have more access to 
other barred owls (Kelly and Forsman 2004:808). Further, Kelly and 
Forsman (2004) documented only 47 hybrids out of more than 9,000 banded 
northern spotted owls and barred owls in Oregon and Washington from 
1970 to 1999. Thus, we conclude that there is not substantial 
scientific information indicating that hybridization with barred owls 
poses a threat to the continued existence of the California spotted 
    However, as stated in the petition, barred owls apparently have 
displaced many northern spotted owls from their territories (Kelly et 
al. 2003, Pearson and Livezey 2003, Gremel 2004), and have expanded 
their range into that of the California spotted owl (Dark et al. 1998) 
as far south as Sequoia National Park. Information in our files 
indicates that, during the past 2 years, the known range of barred owls 
has expanded 200 miles southward in the Sierras, including two hybrid 
spotted/barred owls in the Eldorado National Forest (Seamans et al. in 
press 2005, Seamans in litt. 2005b) and a male barred owl in Kings 
Canyon National Park (Steger et al. in review). Other information in 
our files shows that barred owls physically attack (Pearson and Livezey 
2003) and possibly kill (Leskiw and Guti[eacute]rrez 1998) northern 
spotted owls as well as negatively affect northern spotted owl site 
occupancy (Kelly et al. 2003, Pearson and Livezey 2003), reproduction 
(Olson et al. 2004, Livezey 2005), and survival (Anthony et al. 2004). 
Thus, we have determined that the petition and our files present 
substantial scientific information to conclude that barred owls 
constitute a threat to site occupancy, reproduction, and survival of 
California spotted owls.
    To summarize Factor E, neither the petition nor information in our 
files present substantial scientific information regarding the threats 
to California spotted owls from climate or from hybridization with 
barred owls. However, we find that the petition and information in our 
files present substantial scientific information regarding the threat 
of fires to California spotted owl habitat and of barred owls to site 
occupancy, reproduction, and survival of California spotted owls.

Summary of Threats Analysis

    The petitioners have not presented substantial new scientific 
information on many of the threats to California spotted owls and their 
habitat (e.g., effects from past logging, livestock grazing, urban 
development, and recreation) that were addressed in our 12-month 
finding of February 14, 2003 (68 FR 7580). However, as noted by the 
petition, the following changes have taken place during the past 2 
years that may affect the status and distribution of the California 
spotted owl or change our understanding of possible declines in 
California spotted owl populations: (1) Revisions to the 2001 SNFPA 
(USFS 2001) in the 2004 SNFPA (USFS 2004a); (2) revisions to the 
California State Forest Practices Code; (3) possible changes to the 
draft meta-analysis of the population dynamics of the California 
spotted owl in the final, published meta-analysis (Franklin et al. 
2004); (4) impacts of recent fires and anticipated future fires in 
spotted owl habitat; and (5) further range expansion of the barred owl. 
These changes constitute substantial information and thus justify 
further detailed analysis in a status review and 12-month finding.


    We have reviewed the petition and other information available in 
our files. Based on this review, we find that the petition and 
information in our files present substantial information that listing 
the California spotted owl as threatened or endangered may be 
    The petition also requested that critical habitat be designated for 
the California spotted owl. If we determine in our 12-month finding 
that listing the California spotted owl is warranted, we will address 
the designation of critical habitat in the subsequent proposed listing 
rule or as funding allows.

References Cited

    A complete list of all references cited herein is available, upon 
request, from the Sacramento Fish and Wildlife Office (see ADDRESSES 


    The primary author of this notice is Kent Livezey, Western 
Washington Fish and Wildlife Office, U.S. Fish and Wildlife Service, 
510 Desmond Drive SE, Lacey, Washington 98503.

    Authority: The authority for this action is the Endangered 
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).

[[Page 35614]]

    Dated: June 13, 2005.
Elizabeth H. Stevens,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 05-11938 Filed 6-20-05; 8:45 am]